| multisensory activation of the phosphorelay initiating sporulation in bacillus subtilis: identification and sequence of the protein kinase of the alternate pathway. | the phosphorelay is the signal-transduction system recognizing and integrating environmental signals to initiate sporulation. the major signal input to the phosphorelay is an atp-dependent kinase, kina, responsible for phosphorylating the spoof protein. mutants lacking kina, however, still sporulate, suggesting that other kinases can fulfil its role. in order to identify these kinases, genes for kinases were isolated by hybridization using a degenerate oligonucleotide probe designed for common r ... | 1993 | 8497199 |
| rehydration induces rapid onset of lipid biosynthesis in desiccated nostoc commune (cyanobacteria). | water, which contained [1,3-3h]glycerol, [35s]sodium sulfate, or [32p]sodium orthophosphate, was used to rehydrate air-dried cells of the desiccation-tolerant filamentous cyanobacterium nostoc commune. the cells retained their capacities for the uptake and transport of all three compounds and, in response to rewetting, they mobilized the radiolabels into lipid precursors and initiated complex lipid biosynthesis. the onset of these events, measured in short-term, long-term and pulse-chase labelin ... | 1993 | 8504158 |
| interaction of cryptophycin 1 with tubulin and microtubules. | the cryptophycins are newly discovered antimitotic agents isolated from the cyanobacterium nostoc. previous studies using cultured cells demonstrated that microtubules are the target of these compounds. we have studied the interaction of cryptophycin 1 with tubulin and microtubules in vitro. cryptophycin 1 is an effective inhibitor of tubulin polymerization, causes tubulin to aggregate, and depolymerizes microtubules to linear polymers somewhat similar to the spiral-like structures produced by t ... | 1995 | 8543019 |
| spectroscopical and functional characterization of the hemoglobin of nostoc commune (utex 584 (cyanobacterial). | structural analysis of a monomeric hemoglobin from the cyanobacterium nostoc commune strain utex 584, cyanoglobin (potts et al. (1992) science 256, 1690-1692), is presented. cyanoglobin binds molecular oxygen reversibly, with high oxygen affinity and non-cooperativity. there was no evidence for decreased stability of the pigment at 37 degrees c. cyanoglobin-specific antibodies showed no cross-reactivity with two reference hemoglobins, leghemoglobin a and sperm whale myoglobin. the absorption spe ... | 1996 | 8547335 |
| factors regulating methyl mercury uptake in a cyanobacterium. | the simultaneous addition of dithiothreitol (dtt), mercaptoethanol, and glutathione (30 microm each) and ch3hg+ to nostoc calcicola cells reduced ch3hg+ uptake in the order gsh > dtt > mercaptoethanol. however, the preexposure of cyanobacterial cells to similar thiols resulted in different pattern of ch3hg+ uptake in the sequence: gsh > mercaptoethanol > dtt. light-grown cyanobacterial cells demonstrated a faster initial uptake of ch3hg+ (rate 0.619 mumol ch3hg+ mg-1 protein min-1, 10 min) with ... | 1995 | 8565882 |
| disintegration of phycobilisomes in a rice field cyanobacterium nostoc sp. following uv irradiation. | the effects of ultraviolet-b (uv-b, 280-315 nm) irradiation on survival, growth and phycobilisome assembly have been studied in the n2-fixing cyanobacterium nostoc sp. survival and growth were virtually arrested after 120 min of uv irradiation. the phycobiliprotein fractions showed a decrease in absorption and fluorescence as well as a shift towards shorter wavelengths indicating the impairment of energy transfer from phycobiliproteins to the photosynthetic reaction centers. this was further sup ... | 1995 | 8589643 |
| the devr gene product is characteristic of receivers of two-component regulatory systems and is essential for heterocyst development in the filamentous cyanobacterium nostoc sp. strain atcc 29133. | strain ucd 311 is a transposon-induced mutant of nostoc sp. strain atc c 29133 that is unable to fix nitrogen in air but does so under anoxic conditions and is able to establish a functional symbiotic association with the hornwort anthoceros punctatus. these properties of strain ucd 311 are consistent with previous observations that protection against oxygen inactivation of nitrogenase is physiologically provided within a. punctatus tissue. upon deprivation of combined nitrogen, strain ucd 311 c ... | 1996 | 8606181 |
| transaldolase genes from the cyanobacteria anabaena variabilis and synechocystis sp. pcc 6803: comparison with other eubacterial and eukaryotic homologues. | we have sequenced and analysed the transaldolase (tal) genes from two cyanobacteria, anabaena variabilis (atcc 29413) and synechocystis sp. pcc 6803, which are filamentous heterocyst-forming and unicellular organisms, respectively. the deduced amino acid sequences of the two cyanobacterial tal genes are 78% identical and are highly homologous to both eubacterial and eukaryotic transaldolases (escherichia coli, two yeasts, and man) with values ranging from 54 to 60% amino acid identity. in contra ... | 1996 | 8616240 |
| geosiphon pyriforme, a fungus forming endocytobiosis with nostoc (cyanobacteria), is an ancestral member of the glomales: evidence by ssu rrna analysis. | geosiphon pyriforme inhabiting the surface of humid soils represents the only known example of endocytobiosis between a fungus (zygomycotina; macrosymbiont) and cyanobacteria (nostoc; endosymbiont). in order to elucidate the taxonomical and evolutionary relationship of geosiphon pyriforme to fungi forming arbuscular mycorrhiza (am fungi), the small-subunit (ssu) ribosomal rna genes of geosiphon pyriforme and glomus versiforme (glomales; a typical am fungus) were analyzed and aligned with ssu rrn ... | 1996 | 8660431 |
| ca2+ uptake and its regulation in the cyanobacterium nostoc mac | the uptake of ca2+ and its regulation in the cyanobacterium nostoc mac were investigated. cation uptake pattern was found to be biphasic, consisting of (a) rapid binding of cations to the negatively charged cell surface and (b) its metabolism dependent on intracellular import at least up to 60 min with the saturation at 2 mm ca2+ (km, 1.5 mm, vmax 42.1 nmol ca2+ mg-1 protein min-1 ). the cellular ca2+ uptake was light and atp dependent, and the addition of 3(3,4-dichlorophenyl)-1,1-dimethyl urea ... | 1996 | 8661678 |
| impact of aluminium, fluoride and fluoroaluminate complex on atpase activity of nostoc linckia and chlorella vulgaris. | this study demonstrates a ph-dependent inhibition of mg(2+)- and ca(2+)-atpase activities of nostoc linckia and chlorella vulgaris exposed to alcl3, alf3, naf and alcl3+naf together. alf3 and the combination of alcl3+naf were more inhibitory to both the enzymes as compared with alcl3 and naf. toxicity of the test compounds increased with increasing acidity. interaction of alcl3+naf was additive on n. linckia and c. vulgaris, respectively, at ph 7.5 and 6.8, and synergistic at ph 6.0 and 4.5. in ... | 1996 | 8696079 |
| cyclic peptides and depsipeptides from cyanobacteria: a review. | an elaborate array of structurally-novel and biologically-active cyclic peptides and depsipeptides are found in blue-green algae (cyanobacteria). several of these compounds possess structures that are similar to those of natural products from marine invertebrates. most of these cyclic peptides and depsipeptides, such as the microcystins and the lyngbyatoxins, will probably only be useful as biochemical research tools. a few, however, have the potential for development into useful commercial prod ... | 1996 | 8730577 |
| promiscuity of heme groups in the cyanobacterial cytochrome-c oxidase. | the cyanobacteria nostoc sp. strain mac, anabaena 7937, synechocystis 6803, and anacystis nidulans (synechococcus 6301) were grown and incubated in the light under three different oxygen regimes: phase-a cells were harvested from photoautotrophically growing cultures at a cell density of 2.8-3.2 microliter packed cell mass/ml and an oxygen concentration of approx. 350 microm (corresponding to > 150% air saturation). phase-b cells were harvested 24 hrs after 20 microm 3-(3,4-dichlorophyl)-1,1-dim ... | 1995 | 8747548 |
| regulation of photosynthetic enzymes in light- or dark-grown cyanobacterium nostoc sp. mac. | | 1996 | 8878946 |
| glbn (cyanoglobin) is a peripheral membrane protein that is restricted to certain nostoc spp. | the glbn gene of nostoc commune utex 584 is juxtaposed to nifu and nifh, and it encodes a 12-kda monomeric hemoglobin that binds oxygen with high affinity. in n. commune utex 584, maximum accumulation of glbn occurred in both the heterocysts and vegetative cells of nitrogen-fixing cultures when the rate of oxygen evolution was repressed to less than 25 micromol of o2 mg of chlorophyll a(-1) h(-1). accumulation of glbn coincided with maximum synthesis of nifh and ferredoxin nadp+ oxidoreductase ( ... | 1996 | 8932316 |
| transcriptional regulation of zwf, encoding glucose-6-phosphate dehydrogenase, from the cyanobacterium nostoc punctiforme strain atcc 29133. | the gene encoding glucose-6-phosphate dehydrogenase (g6pd), zwf, in nostoc punctiforme strain atcc 29133 is part of a four-gene operon that also encodes fructose bisphosphatase (fbp), transaldolase (tal) and a gene product termed opca, which is contranscribed with zwf and essential for g6pd activity. the effect of exogenous nitrogen and carbon sources on transcription of these genes was investigated. growth in the presence of ammonium yielded low levels of transcripts encoding all genes of the o ... | 1996 | 8939431 |
| reconstitution of the 2fe-2s center and g = 1.89 electron paramagnetic resonance signal into overproduced nostoc sp. pcc 7906 rieske protein. | the rieske 2fe-2s protein is a distinguishing subunit of the photosynthetic electron transport cytochrome b6f complex in chloroplast and cyanobacterial thylakoid membranes. we have constructed plasmids for overproduction in escherichia coli of fusion, full-length, and truncated forms of the rieske (petc) protein from the cyanobacterium nostoc sp. pcc 7906. a glutathione s-transferase/rieske fusion protein was used to prepare specific chicken egg-yolk antibodies against the rieske protein. expres ... | 1996 | 8952502 |
| effective concentrations of nitrophenolics toward growth yield of selected microalgae and cyanobacteria isolated from soil. | the effective concentrations (ec), which cause a certain percentage of inhibition in growth yield, of four nitrophenolics (o-nitrophenol, m-nitrophenol, p-nitrophenol (pnp), and 2,4-dinitrophenol) and the major metabolites of pnp reduction (p-nitrosophenol and p-aminophenol) toward growth of two microalgae (chlorella vulgaris and scenedesmus bijugatus) and two cyanobacteria (nostoc muscorum and nostoc linckia), all isolated from soil, were determined following linear regression analysis. the ec5 ... | 1995 | 8964245 |
| heterocyst formation. | heterocysts are microaerobic, n2-fixing cells that form in a patterned array within o2-producing filamentous cyanobacteria. structural features of heterocysts can be predicted from consideration of their physiology. this review focuses on the spacing mechanism that determines which cells will differentiate, and on the regulation of the progression of the differentiation process. applicable genetic tools, developed primarily using anabaena pcc 7120, but employed also with nostoc spp., are reviewe ... | 1996 | 8982449 |
| amino acid transport in taxonomically diverse cyanobacteria and identification of two genes encoding elements of a neutral amino acid permease putatively involved in recapture of leaked hydrophobic amino acids. | the activities of uptake of thirteen 14c-labeled amino acids were determined in nine cyanobacteria, including the unicellular strains synechococcus sp. strain pcc 7942 and synechocystis sp. strain pcc 6803; the filamentous strain pseudanabaena sp. strain pcc 6903, and the filamentous, heterocyst-forming strains anabaena sp. strains pcc 7120 and pcc 7937; nostoc sp. strains pcc 7413 and pcc 7107; calothrix sp. strain pcc 7601 (which is a mutant unable to develop heterocysts); and fischerella musc ... | 1997 | 9006043 |
| purification and spectroscopic characterization of a recombinant chloroplastic hemoglobin from the green unicellular alga chlamydomonas eugametos. | hemoglobins (hb), which have the important task of delivering molecular oxygen by facilitating its reversible binding to the heme, are now thought to have evolved in all groups of organisms including prokaryotes, fungi, plants and animals. our recent finding of a light-inducible chloroplastic hb in the green unicellular alga chlamydomonas eugametos has further extend this idea, while raising questions about the function that an hb could play in a high oxygen environment such as in the chloroplas ... | 1996 | 9022709 |
| plasmids from two morphologically distinct cyanobacterial strains share a novel replication origin. | a 2.9-kbp replication origin from a plasmid endogenous to the filamentous cyanobacterium fremyella diplosiphon utex 481 was genetically characterized and sequenced. deletion analysis of the 2.9-kbp dna fragment delimited the minimum region necessary for replication in f. diplosiphon fd33 to approximately 2.5 kbp. dna sequence analysis revealed that the f. diplosiphon plasmid replication origin is structurally very similar to and shares significant identity with the 1.75-kbp replication origin re ... | 1993 | 8366056 |
| effect of cadmium on the bioelement composition of nostoc uam208: interaction with calcium. | | 1997 | 9060371 |
| uv-b-induced synthesis of photoprotective pigments and extracellular polysaccharides in the terrestrial cyanobacterium nostoc commune. | liquid cultures of the terrestrial cyanobacterium nostoc commune derived from field material were treated with artificial uv-b and uv-a irradiation. we studied the induction of various pigments which are though to provide protection against damaging uv-b irradiation. first, uv-b irradiation induced an increase in carotenoids, especially echinenone and myxoxanthophyll, but did not influence production of chlorophyll a. second, an increase of an extracellular, water-soluble uv-a/b-absorbing mycosp ... | 1997 | 9068639 |
| a polyketide-synthase-like gene is involved in the synthesis of heterocyst glycolipids in nostoc punctiforme strain atcc 29133. | a tn5-1063-derived mutant of nostoc punctiforme strain atcc 29133 was unable to fix n2 in air although it reduced acetylene in the absence of o2. mutant strain ucd 307 formed cells morphologically similar to heterocysts, but it failed to synthesize the characteristic heterocyst glycolipids. sequence analysis around the site of insertion revealed an orf of 3,159 base pairs, termed hgle. hgle putatively encodes a 115.4-kda protein containing two domains with conserved amino acid sequences identifi ... | 1997 | 9075624 |
| protein tyrosine phosphorylation in the cyanobacterium anabaena sp. strain pcc 7120. | components of a protein tyrosine phosphorylation/dephosphorylation network were identified in the cyanobacterium anabaena sp. strain pcc 7120. three phosphotyrosine (p-tyr) proteins of 27, 36, and 52 kda were identified through their conspicuous immunoreactions with rc20h monoclonal antibodies specific for p-tyr. these immunoreactions were outcompeted completely by free p-tyr (5 mm) but not by phosphoserine or phosphothreonine. the p-tyr content of the three major p-tyr proteins and several mino ... | 1997 | 9079918 |
| three new cryptophycins from nostoc sp. gsv 224. | cryptophycin 46 (2), -175 (3), and -176(4) have been identified as three new trace constituents of nostoc sp. gsv 224. cryptophycin-46 is an epimer of cryptophycin-3 (5) and to date is the only naturally occurring analogue having the s configuration at c-10 (c-2 in unit b). cryptophycins-175 and -176 also differ in unit b where 3 is the o-methyl analogue of cryptophycin-45 (6) and 4 is the o-desmethyl analogue of cryptophycin-21 (8). the relative and absolute stereochemistries of the three new a ... | 1997 | 9090872 |
| analysis of the sequences within and flanking the cyanoglobin-encoding gene, glbn, of the cyanobacterium nostoc commune utex 584. | a 3.5-kb segment of dna containing nifu glbn nifh nifd was cloned from a gene library of nostoc 584 and sequenced. the nifu-glbn intergenic region contains short tandemly repeated repetitive sequences (5'-aattacg). a sequence corresponding to a nifa-like upstream activator sequence (with the consensus recognition sequence for bifa in anabaena 7120), elements of a nifh promoter and a sequence that may function as a transcription terminator, were identified downstream from glbn. glbn, unique to ce ... | 1994 | 8063099 |
| discovery of cyanovirin-n, a novel human immunodeficiency virus-inactivating protein that binds viral surface envelope glycoprotein gp120: potential applications to microbicide development. | we have isolated and sequenced a novel 11-kda virucidal protein, named cyanovirin-n (cv-n), from cultures of the cyanobacterium (blue-green alga) nostoc ellipsosporum. we also have produced cv-n recombinantly by expression of a corresponding dna sequence in escherichia coli. low nanomolar concentrations of either natural or recombinant cv-n irreversibly inactivate diverse laboratory strains and primary isolates of human immunodeficiency virus (hiv) type 1 as well as strains of hiv type 2 and sim ... | 1997 | 9210678 |
| siderophore production in two species of nostoc as influenced by the toxicity of nitrophenolics. | | 1997 | 9211704 |
| strain characterization and classification of oxyphotobacteria in clone cultures on the basis of 16s rrna sequences from the variable regions v6, v7, and v8. | a major problem in development of a polyphasic taxonomy is that the identification of oxyphotobacterial strains (cyanobacteria and prochlorophytes) in culture collections may be incorrect. we have therefore developed a diagnostic system using the dna sequence polymorphism in the 16s rrna regions v6 to v8 for individual strain characterization and identification. pcr primers amplifying v6 to v8 from oxyphotobacteria in unialgal cultures were constructed. direct solid-phase or cyclic sequencing wa ... | 1997 | 9212409 |
| rrna sequences and evolutionary relationships among toxic and nontoxic cyanobacteria of the genus microcystis. | a primary-structure analysis of the 16s rrna gene was performed with 10 strains representing five described and one unidentified species of the genus microcystis. the phylogenies determined illustrate the evolutionary affiliations among microcystis strains, other cyanobacteria, and related plastids and bacteria. a cluster of 10 strains that included hepatotoxic isolates identified as microcystis aeruginosa formed a monophyletic group. however, the genus microcystis appeared to be polyphyletic an ... | 1997 | 9226902 |
| ornithine cycle in nostoc pcc 73102: presence of an in vitro functional argininosuccinate lyase. | the presence of argininosuccinate lyase (asl), an enzyme catalyzing the final step of arginine biosynthesis, was demonstrated in the heterocystous cyanobacterium nostoc pcc 73102 by measuring in vitro enzyme activity and by visualization of asl in native protein gels. activity staining of a native page gel revealed one asl-dependent band with a molecular mass of about 240 kda. a colorimetric assay for asl based on the measurement of urea produced from arginine in the presence of an excess of arg ... | 1997 | 9228773 |
| isolation, primary sequence determination, and disulfide bond structure of cyanovirin-n, an anti-hiv (human immunodeficiency virus) protein from the cyanobacterium nostoc ellipsosporum. | a novel anti-hiv protein, cyanovirin-n (cv-n), was isolated from an aqueous cellular extract of the cultured cyanobacterium (blue-green alga) nostoc ellipsosporum, purified by reverse-phase hplc, and sequenced by n-terminal edman degradation of the intact protein and peptide fragments produced by endoproteinase digestions. cv-n consists of a single 101 amino acid chain which exhibits significant internal sequence duplication, but no significant homology to previously described proteins or to the ... | 1997 | 9299483 |
| characterization of cyanobacteria by sds-page of whole-cell proteins and pcr/rflp of the 16s rrna gene. | planktonic, filamentous cyanobacterial strains from different genera, both toxic and nontoxic strains, were characterized by sds-page of whole-cell proteins and pcr/rflp of the 16s rrna gene. total protein pattern analysis revealed the mutual relationships at the genus level. restriction fragment length polymorphism (rflp) of the 16s rrna gene with reference strains proved to be a good method for the cyanobacterial taxonomy. the nonheterocystous strains outgrouped from the nitrogen-fixing ones. ... | 1997 | 9382701 |
| sequence variation of the trna(leu) intron as a marker for genetic diversity and specificity of symbiotic cyanobacteria in some lichens. | we examined the genetic diversity of nostoc symbionts in some lichens by using the trna(leu) (uaa) intron as a genetic marker. the nucleotide sequence was analyzed in the context of the secondary structure of the transcribed intron. cyanobacterial trna(leu) (uaa) introns were specifically amplified from freshly collected lichen samples without previous dna extraction. the lichen species used in the present study were nephroma arcticum, peltigera aphthosa, p. membranacea, and p. canina. introns w ... | 1998 | 9435083 |
| glutamine synthetase from n2-fixing cyanobacterium nostoc muscorum--purification, biochemical and immunological characteristics. | a modified procedure for purification of glutamine synthetase [l-glutamate: ammonia ligase (adp-forming)] from n2-fixing cyanobacterium n. muscorum, to homogeneity is described using deae-sephadex and blue-sepharose affinity chromatography. specific activities of the purified enzyme in biosynthetic and transferase assays were 8.5 and 28 mumole product formed min-1 mg-1 protein. apparent molecular mass of native gs enzyme was about 610 kda as estimated by gel filtration. on sds-page the enzyme pr ... | 1997 | 9475046 |
| a comparison of physical properties, oxalate-oxalic acid soluble substances, protein content, and in vitro protein digestibility of the blue-green alga nostoc commune vauch. from the philippines and japan. | the physical properties, amount of oxalate-oxalic acid soluble substances (ooss), protein and in vitro protein digestibility of nostoc commune from the philippines and japan were determined. the samples were the spherical type from the philippines (ps), the dry field discoid type from the philippines (pd), and the dry field discoid type from japan (jd). the discoid types, pd and jd, regardless of origin showed higher settling volume in water (sv) and bulk density than ps. the ooss values obtaine ... | 1997 | 9477423 |
| uvb-induced reduction in biomass and overall productivity of cyanobacteria. | effect of middle wave ultraviolet radiation (uvb) was studied in three different species of cyanobacteria (nostoc, anabaena and scytonema) by estimating their growth pattern, biomass yield, chlorophyll content, total starch and protein content. the results show that exposure of the cyanobacteria with uvb dose corresponding to an increase or decrease of 20% in its environmental flux will have drastic effects on biomass production, photosynthetic rate and nitrogen fixation. cyanobacteria are prima ... | 1998 | 9514891 |
| [the destruction of microscopic organisms by their irradiation with a special form of uhf electromagnetic signals]. | electromagnetic signals of special form produced by an ultra-high frequency generator were used to destroy various microorganisms: baker's yeast; blue-green alga nostoc muscorum; mold fungus; and two flagellates, plant flagellate euglena gracilis and an animal flagellate parasitizing on humans. the control samples before irradiation and experimental samples damaged and destroyed by irradiation were examined on a microscope with a computer system of image analysis. the results are presented as co ... | 1997 | 9518060 |
| hydrogen uptake in nostoc sp. strain pcc 73102. cloning and characterization of a hupsl homologue. | structural genes encoding an uptake hydrogenase of nostoc sp. strain pcc 73102 were isolated. from partial libraries of genomic dna, two clones (pnfo01 and pnfo02) were selected and sequenced, revealing the complete sequence of both a hups (960 bases) and a hupl (1,593 bases) homologue in nostoc sp. strain pcc 73102. a comparison between the deduced amino acid sequences of hups and hupl of nostoc sp. strain pcc 73102 and anabaena sp. strain pcc 7120 showed that the hups proteins are 89% identica ... | 1998 | 9531626 |
| electrophoretic applications of phycobiliproteins. | phycobiliproteins are homologous chromoproteins which constitute the phycobilisomes, the light harvesting complexes of the photosynthetic apparatus in cyanobacteria, rhodophyta and cryptophyta. in the present work, phycocyanin (pc) and phycoerythrin (pe) from a nostoc species are proposed as protein markers for electrophoretic techniques. phycocyanin is a blue-colored phycobiliprotein; it carries phycocyanobilin as chromophoric group and is composed of two subunits, alpha and beta, with mr of 14 ... | 1998 | 9548282 |
| characterization of host-range mutants of cyanophage n-1. | fifteen host-range (h) mutants of cyanophage n-1 were characterized with reference to their efficiency of plating, time of appearance, morphology and size of plaques on nostoc muscorum and its three phage-resistant (nm 1/n-1, nm 2/n-1 and nm 8/n-1) mutants. while phage n-1 did not adsorb to the three phage-resistant mutants, the h mutants differed one from the other in having lower or higher adsorption rate constants on n. muscorum or the phage-resistant mutants. the inability of majority of h m ... | 1997 | 9607077 |
| cloning and characterisation of the pknd gene encoding an eukaryotic-type protein kinase in the cyanobacterium anabaena sp. pcc7120. | protein phosphorylation catalysed by protein kinases is an important mechanism for signal transduction in both prokaryotes and eukaryotes. a novel gene, pknd, encoding a protein similar to eukaryotic-type protein kinases, was cloned from anabaena sp. pcc7120. the n-terminal region of pknd is 60% identical to that of pkna, another putative ser/thr kinase from the same strain. both pkna and pknd have c-terminal regions that are rich in pro and thr residues. expression of pknd was undetectable by r ... | 1998 | 9613569 |
| characterization of the glnb gene product of nostoc punctiforme strain atcc 29133: glnb or the pii protein may be essential. | bacterial pii proteins, encoded by glnb genes, are central signalling molecules in nitrogen regulatory pathways and are modulated by post-translational modification in response to the cellular nitrogen status. the glnb gene was cloned from the filamentous heterocyst-forming cyanobacterium nostoc punctiforme strain atcc 29133 (pcc 73102) by heterologous hybridization to a synechococcus sp. strain pcc 7942 gene fragment. expression of the cloned gene was verified by hybridization to n. punctiforme ... | 1998 | 9639924 |
| multiple oligomeric forms of glucose-6-phosphate dehydrogenase in cyanobacteria and the role of opca in the assembly process. | multiple molecular forms of glucose-6-phosphate dehydrogenase (g6pdh) were detected by activity staining in non-denaturing polyacrylamide gels of cell-free extracts from a range of cyanobacteria including anabaena sp. pcc 7120, synechococcus sp. pcc 7942, plectonema boryanum pcc 73110, synechocystis sp. pcc 6803, nostoc sp. mac pcc 8009 and the marine strain synechococcus sp. wh7803. in most of the species tested, the profile of g6pdh activities was modulated by the growth of the cells in the pr ... | 1998 | 9639925 |
| evolution of cyanobacteria by exchange of genetic material among phyletically related strains. | the cyanobacterial radiation consists of several lineages of phyletically (morphologically and genetically) related organisms. several of these organisms show a striking resemblance to fossil counterparts. to investigate the molecular mechanisms responsible for stabilizing or homogenizing cyanobacterial characters, we compared the evolutionary rates and phylogenetic origins of the small-subunit rrna-encoding dna (16s rdna), the conserved gene rbcl (encoding d-ribulose 1,5-bisphosphate carboxylas ... | 1998 | 9642201 |
| binding of the epoxide cryptophycin analog, ly355703 to albumin and its effect on in vitro antiproliferative activity. | cryptophycin, isolated from the cyanobacterium nostoc, is a cytotoxic dioxadiazacyclohexadecenetetrone which causes rapid depletion of microtubules in intact cells. in the present report, the effect of protein binding of a new synthetic cryptophycin analog, ly355703 (cryptophycin 52), is discussed. in handling the compound, it was found to bind extensively to surfaces, and a high degree of plasma protein binding was also observed (about 99% in human plasma). similarly, while ly355703 displays po ... | 1998 | 9683814 |
| structure and properties in solution of psad, an extrinsic polypeptide of photosystem i. | psad is a small, extrinsic polypeptide located on the stromal side (cytoplasmic side in cyanobacteria) of the photosystem i reaction centre complex. the gene from the cyanobacterium nostoc sp. pcc 8009 was expressed in escherichia coli and the structure of the recovered protein in solution investigated. size-exclusion chromatography, dynamic light scattering and measurement of 15n transverse relaxation times showed that the protein is a stable dimer in solution, whereas in the reaction centre co ... | 1998 | 9692933 |
| a transposition-induced mutant of nostoc ellipsosporum implicates an arginine-biosynthetic gene in the formation of cyanophycin granules and of functional heterocysts and akinetes. | in strain ne1 of tn5-1058-mutagenized nostoc ellipsosporum, the transposon was found within a gene whose translation product is similar in amino acid sequence to the arginine-biosynthetic protein n-acetylglutamate semialdehyde dehydrogenase encoded by argc of bacillus subtilis. the argc reported from anabaena sp. strain pcc 7120 hybridized to a sequence different from the one interrupted by the transposon in ne1. the newly identified gene from n. ellipsosporum was denoted argl. the argl mutation ... | 1998 | 9695912 |
| cellular uptake of a novel cytotoxic agent, cryptophycin-52, by human thp-1 leukemia cells and h-125 lung tumor cells. | cryptophycin (cp) is a newly developed anticancer agent isolated from the terrestrial cyanobacteria of the genus nostoc. cp is a mitotic inhibitor, causing cells to accumulate in mitosis with the disappearance of intracellular microtubules. in this report, we studied the interaction and uptake of a new synthetic cp analog, cp-52, with 2 human tumor cell lines, thp-1 and h-125. in vitro colony-forming assay showed that cp-52 has antiproliferative activity against thp-1 and h-125 cell lines with i ... | 1998 | 9714056 |
| partial purification and characterization of ornithine carbamoyl transferase (oct) from the cyanobacterium nostoc sp. strain pcc 73102 | ornithine carbamoyl transferase (oct) catalyzes the formation of citrulline and orthophosphate from ornithine and carbamoyl phosphate. we have partially purified oct from the filamentous cyanobacterium nostoc sp. strain pcc 73102, using ammonium sulfate precipitation (35-55%), a gel-filtration column (sephacryl s-200), followed by an affinity column (sepharose-6b-palo). the partially purified oct was analyzed on native-page and shown to be an active enzyme with an estimated molecular weight of a ... | 1998 | 9732532 |
| mutation of an alternative sigma factor in the cyanobacterium nostoc punctiforme results in increased infection of its symbiotic plant partner, anthoceros punctatus. | an alternative group 2 sigma factor was identified in the nitrogen-fixing, symbiotically competent cyanobacterium nostoc punctiforme and designated sigh. transcription of sigh was specifically induced within 1.5 h following exposure of n. punctiforme to its symbiotic plant partner, anthoceros punctatus. a mutation in sigh resulted in a sixfold-higher initial infection of a. punctatus tissue without a parallel increase in nitrogen-fixing activity. | 1998 | 9733698 |
| a simple procedure for purifying the major chloroplast fructose-1,6-bisphosphatase from spinach (spinacia oleracea) and characterization of its stimulation by sub-femtomolar mercuric ions. | a rapid procedure for the purification of the redox-regulated chloroplast fructose-1,6-bisphosphatase [ec 3.1.3.11] from spinach leaf extract to homogeneity is described. no thiol-reducing agents were present during the purification and the enzyme is > 99% in the oxidized form. a rapid procedure to reduce and activate the fru-1,6-p2ase by dithiothreitol in the absence of thioredoxin is described. reduction activates the enzyme up to several hundred-fold when assayed at ph 8.0 with 2 mm mg2+. the ... | 1998 | 9735161 |
| tenuecyclamides a-d, cyclic hexapeptides from the cyanobacterium nostoc spongiaeforme var. tenue. | four modified cyclic hexapeptides, tenuecyclamides a-d (1-4), were isolated along with the known antibiotic, borophycin (5), from the methanol extract of nostoc spongiaeforme var. tenue (tau strain il-184-6). the planar structure of tenuecyclamides a-d (1-4) was determined by homonuclear and inverse-heteronuclear 2d-nmr techniques as well as by high-resolution mass spectrometry measurements. the absolute configuration of the asymmetric centers was studied by marfey's method for hplc. the stereoc ... | 1998 | 9784161 |
| differential behaviour of two cyanobacterium species to uv radiation. artificial uv radiation induces phycoerythrin synthesis. | altitude is an important factor contributing to the local uv-b climate. in the european alps solar uv-b increases approximately 21% 1000 m-1. a nostoc muscorum (utex 389) originating from scotland and a nostoc sp. isolated from a highland lake (yanaqocha) located 3980 m above sea level (cusco, perú) have been used in a study where the tolerance to uv radiation (uvr) stress of both species was determined. following irradiation doses of 15 kj uv (uv-a plus uv-b, equivalent to approximately 6 h exp ... | 1998 | 9800379 |
| a pcr technique based on the hip1 interspersed repetitive sequence distinguishes cyanobacterial species and strains. | the use of primers based on the hip1 sequence as a typing technique for cyanobacteria has been investigated. the discovery of short repetitive sequence structures in bacterial dna during the last decade has led to the development of pcr-based methods for typing, i.e., distinguishing and identifying, bacterial species and strains. an octameric palindromic sequence known as hip1 has been shown to be present in the chromosomal dna of many species of cyanobacteria as a highly repetitious intersperse ... | 1998 | 9802020 |
| safety evaluation of nostoc flagelliforme (nostocales, cyanophyceae) as a potential food. | the safety of the alga genus nostoc flagelliforme born. etflah. as a human food source was evaluated in an oral acute toxicity study and in a 28-day oral subacute toxicity study using rats. in the acute toxicity study, the dried powder of n. flagelliforme was orally administered to male and female rats at a dose of 1250 mg/kg and 2500 mg/kg. neither mortality nor changes in general condition were observed in either the study groups or the control group over a 14-day observation period. in the su ... | 1998 | 9862649 |
| transcriptional regulation of nostoc uptake hydrogenase. | filamentous, heterocystous cyanobacteria may contain both an uptake hydrogenase (encoded by hupsl) and a bidirectional enzyme (encoded by hoxfuyh). the present study identifies three strains (anabaena variabilis, nostoc muscorum and nostoc sp. strain pcc 73102) with a contiguous hupl in both vegetative cells and heterocysts. the two nostoc strains differ in either containing a bidirectional enzyme (n. muscorum) or lacking this enzyme (n. pcc 73102). transcriptional studies, using reverse transcr ... | 1999 | 9919654 |
| a cyanobacterial hemoglobin with unusual ligand binding kinetics and stability properties. | the glbn gene of the cyanobacterium nostoc commune utex 584 encodes a hemoprotein, named cyanoglobin, that has high oxygen affinity. the basis for the high oxygen affinity of cyanoglobin was investigated through kinetic studies that utilized stopped-flow spectrophotometry and flash photolysis. association and dissociation rate constants were measured at 20 degrees c for oxygen, carbon monoxide, nitric oxide, and methyl and ethyl isocyanides. the association rate constants for the binding of thes ... | 1999 | 10026295 |
| sequence of a 2.6-kb cryptic plasmid from a marine cyanobacterium synechococcus sp. | we have shown previously that the copy number of plasmid psy10 from the marine cyanobacterium synechococcus sp. nkbg 042902 is dependent on the salinity of the growth medium. we report here the complete nucleotide sequence (2561 bp) of this plasmid. the longest open reading frame, orf-b (1.08 kb), occurs on a 1.6-kb ecori fragment. this orf encodes a putative protein which is 360 aa residues in length and is 37.8% homologous to the replication protein of plasmid pca2.4 from synechocystis sp. str ... | 1994 | 7899510 |
| characterization of ts-mutants of cyanophage n-1 by their inactivation by physical and chemical agents. | the effect of temperature, ultraviolet (uv) light and ethylenediaminetetraacetic acid (edta) on the stability of cyanophage n-1, infecting the cyanobacterium nostoc muscorum was studied. complete inactivation of the phage occurred at 60 degrees c in 6 mins. all the temperature-sensitive (ts) mutants exhibited faster inactivation at 50 degrees c than the wild type. uv light readily inactivated the particles of the wild giving a survival of 3.44% at a dose of 60 secs. all the ts-mutants were found ... | 1995 | 7676938 |
| allophycocyanin from nostoc sp. phycobilisomes. properties and amino acid sequence at the nh2 terminus of the alpha and beta subunits of allophycocyanins i, ii, and iii. | allophycocyanin from nostoc sp. phycobilisomes was separated into four spectrally distinct components designated allophycocyanin i, b, ii, and iii by adsorption chromatography on brushite columns. allophycocyanins i and b had red-shifted fluorescence emission maxima, and on this basis, may function in transfer of excitation energy from phycobilisomes to chlorophyll a. allophycyanins ii and iii, which together comprise 70% of the total allophycocyanin, have absorption maxima at 648 nm and 650 nm, ... | 1980 | 7410430 |
| regulatory effect of hydrogen on nitrogenase activity of the blue-green alga (cyanobacterium) nostoc muscorum. | preincubation of the blue-green alga (cyanobacterium) nostoc muscorum under an atmosphere of argon plus acetylene in the light led to a greater than fourfold increase of light-induced hydrogen evolution and to a 50% increase of acetylene reduction, as compared to cells that had not been preconditioned. the basic and the increased hydrogen evolution were both due to nitrogenase activity. furthermore, after preincubation the hydrogen uptake, usually observed with unconditional cells, was abolished ... | 1980 | 6767700 |
| metabolic activities of isolated akinetes of the cyanobacterium nostoc spongiaeforme. | intact akinetes (spores) of the cyanobacterium nostoc spongiaeforme can be isolated free of vegetative cells and heterocysts. the akinetes remain viable for at least 2 weeks in distilled water. they do not germinate in water but do so readily when transferred subsequently to cyanobacterial growth medium. isolated, nongerminating akinetes incorporated 35s from na235so4 into protein and lipid. similar incorporation was observed when akinetes were isolated from old cultures (containing primarily ak ... | 1983 | 6413494 |
| purification and properties of glycogen isolated from a blue-green alga, nostoc muscorum. | alpha granules were isolated from a blue-green alga, nostoc muscorum, in large quantities and high purity by sucrose density gradient centrifugation. sodium deoxycholate was used to eliminate membrane contamination. isolated alpha granules from this species have average dimension of 31 nm in width and 65 nm in length. each alpha granule consists of two equal parts. attempts to dissociate the intact granule under mild conditions into relatively large subunits did not succeed. analytical centrifug ... | 1971 | 4993320 |
| [nitrogen excretion by nitrogen fixing blue-green algae. i. growth of anabaena cylindriea and nostoc muscorum in various media, at different temperatures, and under light of different wavelengths (author's transl)]. | | 1973 | 4272180 |
| phycobilisomes in blue-green algae. | fifteen species of freshwater blue-green algae, including unicellular, filamentous, and colonial forms, were subjected to a variety of fixatives, fixation conditions, and stains for comparison of the preservation of phycobilisomes. absorption spectra of the corresponding in vivo and released photosynthetic pigments, in 10 of the species that were maintained in culture, demonstrated the presence of phycocyanin in all 10 species and phycoerythrin in only 2 of them. spectroscope and electron micros ... | 1974 | 4204443 |
| role of reduced exogenous organic compounds in the physiology of the blue-green bacteria (algae): photoheterotrophic growth of a "heterotrophic" blue-green bacterium. | nostoc sp. (strain mac) was shown to be capable of using glucose, fructose, or sucrose as a sole source of carbon and energy in the dark. in the light in the absence of exogenously supplied co(2), this strain exhibited a more versatile metabolism. in addition to the three sugars above, glycerol and acetate served as sole sources of carbon. this photoheterotrophic growth in the absence of exogenously supplied co(2) appears to involve o(2)-evolving photosynthesis. the action spectrum for photohete ... | 1973 | 4196252 |
| effect of tryptophan on 2,4-dichlorophenoxyacetic acid toxicity in the nitrogen-fixing-cyanobacterium nostoc linckia. | the combined effect of a hormone weed killer 2,4-dichlorophenoxyacetic acid (2,4-d) and an amino acid (tryptophan) has been studied on growth and heterocyst differentiation in the cyanobacterium nostoc linckia. 2.4-d at 100 micrograms/ml stimulated growth and heterocyst frequency in combined nitrogen-free medium while its higher concentrations inhibited both. tryptophan under similar conditions promoted much growth yield with 3-4 fold enhanced heterocyst frequency than the control. such heterocy ... | 1986 | 3083089 |
| immunologically cross-reactive and redox-competent cytochrome b6/f-complexes in the chlorophyll-free plasma membrane of cyanobacteria. | plasma and thylakoid membranes were separated and purified from cell-free extracts of the cyanobacteria anacystis nidulans, synechocystis 6714, anabaena variabilis and nostoc sp. strain mac. immunoblots of the membrane proteins using antisera raised against subunits i-iv of the chloroplast b6/f-complex gave evidence for the presence of a homologous complex in both plasma and thylakoid membranes from the four species of cyanobacteria investigated. both plasma and thylakoid membranes catalyzed the ... | 1990 | 2121543 |
| response of enzymes involved in the processes of antioxidation towards benthiocarb and methylparathion in cyanobacteria nostoc muscorum. | | 1991 | 1912703 |
| differentiation of free-living anabaena and nostoc cyanobacteria on the basis of fatty acid composition. | the cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera anabaena and nostoc were analyzed to differentiate the genera. the fatty acid compositions of 10 anabaena strains and 10 nostoc strains that were grown for 12 days on bg-11o medium were determined by gas-liquid chromatography-mass spectroscopy. of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at l ... | 1992 | 1581185 |
| viability of lyophilized cyanobacteria (blue-green algae). | lyophilizatin of 13 cyanobacterial cultures belonging to seven genera was attempted in a variety of suspending substances. all organisms survived lyophilization when suspended in lamb serum. some of the organisms could be successfully lyophilized in horse serum, beef serum, fetal bovine serum, or human ascites fluid. with the exception of nostoc muscorium, none of the organisms survived lyophilization in skim milk medium, egg albumin medium, or jansen salts medium. | 1976 | 827240 |
| effect of pesticides on blue-green algae and nitrogen-fixation. | the effects of the pesticides, amitrol, a derivative of amitrol (viz. 3,5-diamino-1,2,4-triazole), diquat, paraquat, linuron, mcpa, malathion, and monuron, were studied on the nitrogen-fixing algae, anabaena cylindrica, aulosira sp., calothrix elenkenii. chlorogloeae frischii, cylindrospermum muscicola, nostoc sp. from collema tenax, nostoc muscorum tolypothrix tenuis, and westiellopsis sp. in general, two types of response were discernible; an initial period of depression succeeded by an increa ... | 1975 | 808179 |
| transfer of nitrogen-fixing (nif) genes in the blue-green alga nostoc muscorum. | | 1975 | 803368 |
| toxicity of carbofuran to blue-green alga nostoc muscorum. | effect of commercial grade pesticide furadan (3% a.i. as carbofuran) was studied on the survival, growth and nitrogen fixation of blue-green alga nostoc muscorum. the lower concentration of furadan i.e. 25 microgram/ml enhanced survival, growth and nitrogen fixation in the alga whereas these were gradually inhibited in higher concentrations (50--1000 microgram/ml) and the presence of more than 1200 microgram/ml was algicidal. the preliminary observations revelaed that pesticide is biodegraded by ... | 1978 | 104755 |
| effects of some inorganic elements on nitrogen-fixation in blue-green algae and some ecological aspects of pollution. | nitrogen-fixation by two species of nostoc, one of them a lichen phycobiont, was generally stimulated by low concentrations of arsenic, cadmium, nickel, lead, palladium, and zinc. higher concentrations (0.025 to 0.125 ppm) of arsenic, nickel, and palladium were also stimulatory; however, higher concentrations of cadmium, lead, and zinc tended to inhibit fixation. with the exception of palladium and zinc at low concentrations these six tested elements tended to inhibit nitrogen-fixation in chloro ... | 1978 | 104450 |
| comparative studies on two ferredoxins from the cyanobacterium nostoc strain mac. | two ferredoxins were isolated from the cyanobacterium nostoc strain mac grown autotrophically in the light or heterotrophically in the dark. in either case approximately three times as much ferredoxin i as ferredoxin ii was obtained. both ferredoxins had absorption maxima at 276, 282 (shoulder), 330, 423 and 465 nm in the oxidized state, and each possessed a single 2 fe-2s active centre. their isoelectric points were approx. 3.2. the midpoint redox potentials of the ferredoxins differed markedly ... | 1978 | 99139 |
| effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue-green alga nostoc muscorum. | the effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (hch) in growth medium to the n2-fixing blue-green alga nostoc muscorum. it was observed that all these chemicals had some effects on toxicity. the toxicity of both carbofuran and hch was reduced to some extent in the presence of higher concentrations ... | 1979 | 94720 |
| photolysis of water coupled to nitrate reduction by nostoc muscorum subcellular particles. | | 1976 | 9086 |
| effect of nadp on light-induced cytochrome changes in membrane fragments from a blue-green alga. | the effect of nadp+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragements prepared from the blue-green algae nostoc muscorum (strain 7119) that had high rates of electron transport from water to nadp+ and from an artificial electron donor, reduced dichlorophenolindophenol (dciph2) to ndap+. the membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. with dciph2 as the elec ... | 1976 | 2320 |
| a hormogonium regulating locus, hrmua, of the cyanobacterium nostoc punctiforme strain atcc 29133 and its response to an extract of a symbiotic plant partner anthoceros punctatus. | transposon-generated mutant strain ucd 328 of nostoc punctiforme strain atcc 29133 has a phenotype of an increased sensitivity to a hormogonium-inducing factor exuded by a symbiotic plant partner, anthoceros punctatus, and an initial increased hormogonium-dependent infection of the plant. sequence analysis showed that the transposition site in strain ucd 328 lies within a 1,251-bp open reading frame (orf), designated hrma, that displays no significant similarity to known database sequences. a se ... | 1997 | 9057333 |
| dechlorination of lindane by the cyanobacterium anabaena sp. strain pcc7120 depends on the function of the nir operon. | nitrate is essential for lindane dechlorination by the cyanobacteria anabaena sp. strain pcc7120 and nostoc ellipsosporum, as it is for dechlorination of other organic compounds by heterotrophic microorganisms. based on analyses of mutants and effects of environmental factors, we conclude that lindane dechlorination by anabaena sp. requires a functional nir operon that encodes the enzymes for nitrate utilization. | 1997 | 9150239 |
| the frua signal transduction protein provides a checkpoint for the temporal co-ordination of intercellular signals in myxococcus xanthus development. | during fruiting body morphogenesis in myxococcus xanthus, the intercellular c-signal induces aggregation, sporulation and developmental gene expression. to understand how a single signal system may induce temporally separated processes, we have focused on the class ii gene, which codes for an essential component in the c-signal transduction pathway. we report that class ii is identical to frua and codes for a dna binding response regulator. transcription of frua is developmentally regulated and ... | 1998 | 10094629 |
| a novel extracellular diterpenoid with antibacterial activity from the cyanobacterium nostoc commune. | a novel extracellular metabolite with an unprecedented diterpenoid skeleton, 8-[(5-carboxy-2-hydroxy)benzyl]-2-hydroxy-1,1,4a,7, 8-pentamethyl-1,2,3,4,4a,6,7,8,8a,9,10,10a-dodecahydrophenanthrene , has been isolated from the culture medium of the terrestrial cyanobacterium nostoc commune vaucher (eawag 122b) by means of bioguided isolation. the molecule was designated as noscomin. the structure was determined by spectroscopic methods, mainly nmr and mass spectrometry. noscomin exhibited antibact ... | 1999 | 10096870 |
| cyanovirin-n binds to gp120 to interfere with cd4-dependent human immunodeficiency virus type 1 virion binding, fusion, and infectivity but does not affect the cd4 binding site on gp120 or soluble cd4-induced conformational changes in gp120. | cyanovirin-n (cv-n), an 11-kda protein isolated from the cyanobacterium nostoc ellipsosporum, potently inactivates diverse strains of human immunodeficiency virus type 1 (hiv-1), hiv-2, and simian immunodeficiency virus. while it has been well established that the viral surface envelope glycoprotein gp120 is a molecular target of cv-n, the detailed mechanism of action is of further interest. we compared matched native and cv-n-treated virus preparations in a panel of assays that measure viral re ... | 1999 | 10196334 |
| extended heme promiscuity in the cyanobacterial cytochrome c oxidase: characterization of native complexes containing hemes a, o, and d, respectively. | the cyanobacteria anacystis nidulans (synechococcus sp. pcc6301), synechocystis sp. pcc6803, anabaena sp. pcc 7120, and nostoc sp. pcc8009 were grown photoautotrophically under reduced oxygen tension in a medium with sulfate replaced by thiosulfate and nitrate replaced by ammonium as the s- and n-sources, respectively. in addition, anabaena and nostoc were grown under dinitrogen-fixing conditions in a medium free of combined nitrogen. membranes were isolated from late-logarithmic cells (culture ... | 1999 | 10375407 |
| biochemical and genetic evidence for participation of devr in a phosphorelay signal transduction pathway essential for heterocyst maturation in nostoc punctiforme atcc 29133. | in a test of the hypothesis that devr is a response regulator protein that functions in a phosphorelay signal transduction system involved in heterocyst development in nostoc punctiforme atcc 29133, purified affinity-tagged devr was shown to be phosphorylated in vitro by the noncognate sensor kinase envz. site-directed mutagenesis was used to generate n. punctiforme mutants with single amino acid substitutions at the putative phosphorylation site of devr. these mutants exhibited a fox- phenotype ... | 1999 | 10400605 |
| energy-dependent ca(2+) efflux from the cells of nostoc calcicola breb: role of modifying factors | energy-dependent ca(2+) efflux and its regulation from the diazotrophic cyanobacterium nostoc calcicola breb has been investigated. like ca(2+) uptake, ca(2+) efflux pattern also reflected a rapid phase for the first 10 min followed by a slower one lasting up to 1 h with a total of 80 nmol ca(2+) mg(-1) protein (31% of the ca(2+) concentration taken in by such cells at 1 h). ca(2+) efflux kinetics remained hyperbolic with a k(m) of 1.9 mm and v(max) 5.5 nmol mg(-1) protein min(-1). ca(2+) efflux ... | 1999 | 10489433 |
| the solution structure of photosystem i accessory protein e from the cyanobacterium nostoc sp. strain pcc 8009. | psae is a small basic subunit located on the stromal (cytoplasmic) side of photosystem i. in cyanobacteria, this subunit participates in cyclic electron transport and modulates the interactions of the complex with soluble ferredoxin. the psae protein isolated from the cyanobacterium synechococcus sp. strain pcc 7002 adopts the beta topology of an sh3 domain, with five beta strands (betaa through betae) and a turn of 3(10) helix between strands betad and betae [falzone, c. j., kao, y.-h., zhao, j ... | 1999 | 10521281 |
| separation and identification of hydrocarbons and other volatile compounds from cultured blue-green alga nostoc sp. by gas chromatography-mass spectrometry using serially coupled capillary columns with consecutive nonpolar and semipolar stationary phases. | the complex hydrocarbons and volatile compounds produced by cultured blue-green alga nostoc sp. were separated by serially coupled capillary columns with consecutive nonpolar and semipolar stationary phases. more than 130 metabolites including, cyclohexane, cyclopentane, normal saturated hydrocarbons (c7-c30), fatty acids and benzene derivatives were identified by gc-ms. the most abundant family of hydrocarbons identified were derivatives of cyclohexane (41) and cyclopentane (11). most of these ... | 1999 | 10596980 |
| active fe-containing superoxide dismutase and abundant sodf mrna in nostoc commune (cyanobacteria) after years of desiccation. | active fe-superoxide dismutase (sodf) was the third most abundant soluble protein in cells of nostoc commune chen/1986 after prolonged (13 years) storage in the desiccated state. upon rehydration, fe-containing superoxide disumutase (fe-sod) was released and the activity was distributed between rehydrating cells and the extracellular fluid. the 21-kda fe-sod polypeptide was purified, the n terminus was sequenced, and the data were used to isolate sodf from the clonal isolate n. commune drh1. sod ... | 2000 | 10613879 |
| structural characterization of the released polysaccharide of desiccation-tolerant nostoc commune drh-1. | the structure of the viscous extracellular polysaccharide (glycan) of desiccation-tolerant nostoc commune drh-1 was determined through chromatographic and spectroscopic methods. the polysaccharide is novel in that it possesses a 1-4-linked xylogalactoglucan backbone with d-ribofuranose and 3-o-[(r)-1-carboxyethyl]-d-glucuronic acid (nosturonic acid) pendant groups. the presence of d-ribose and nosturonic acid as peripheral groups is unusual, and their potential roles in modulating the rheologica ... | 2000 | 10648523 |
| solution 1h nmr study of the heme cavity and folding topology of the abbreviated chain 118-residue globin from the cyanobacterium nostoc commune. | the globin from the cyanobacterium nostoc commune, abbreviated glbn, which appears to serve as a part of a terminal oxidase rather than as a respiratory pigment, displays relatively normal o2 binding properties, despite the highly abbreviated polypeptide chain, (118 residues) relative to more conventional globins [thorsteinsson, m. v. , bevan, d. r., potts, m., dou, y., eich, r. f., hargrove, m. s., gibson, q. h., and olson, j. s. (1999) biochemistry 38, 2117-2126]. the nature of the heme cavity ... | 2000 | 10684619 |
| novel extracellular diterpenoids with biological activity from the cyanobacterium nostoc commune. | five novel extracellular metabolites with an unprecedented diterpenoid skeleton, 5-[(5-carboxy-2-hydroxy)benzyl]-11-hydroxymethyl-2,5,6,8a, 11-pentamethyldodecahydrocyclopenta<a>naphthalene (1), 5-[(5-carboxy-2-hydroxy)benzyl]-11-formyl-2,5,6,8a, 11-pentamethyl-dodecahydrocyclopenta<a>naphthalene (2), 5-[(5-carboxy-2-hydroxy)benzyl]-11-carboxy-2,5,6,8a, 11-pentamethyl-dodecahydrocyclopenta<a>naphthalene (3), 5-[(5-carboxy-2-hydroxy)benzyl]-11-dihydroxymethyl-2,5,6,8a, 11-pentamethyldodecahydrocy ... | 2000 | 10757714 |
| inhibition of croton oil-induced oedema in mice ear skin by capsular polysaccharides from cyanobacteria. | the anti-inflammatory properties of hydrophilic extracts of the capsular polymers of twelve cyanobacterial strains belonging to the genera phormidium and nostoc from marine and terrestrial habitats were tested topically on croton oil-induced oedema in mice ear skin. the screening program identified several strains as producers of anti-inflammatory products (up to 56% inhibition of the oedema). the inhibition response was dose-dependent. the application of trichloroacetic acid-treated extracts re ... | 2000 | 10763863 |
| n-(cyclohexanecarboxyl)-o-phospho-l-serine, a minimal substrate for the dual-specificity protein phosphatase iphp. | three dual-specific phosphatases [dsps], iphp, vhr, and cdc14, and three protein-tyrosine phosphatases [ptps], ptp-1b, ptp-h1, and tc-ptpa, were challenged with a set of low molecular weight phosphoesters to probe the factors underlying the distinct substrate specificities displayed by these two mechanistically homologous families of protein phosphatases. it was observed that beta-naphthyl phosphate represented an excellent general substrate for both ptps and dsps. while dsps tended to hydrolyze ... | 2000 | 10775432 |
| properties of cyanovirin-n (cv-n): inactivation of hiv-1 by sessile cyanovirin-n (scv-n). | cyanovirin-n (cv-n) is a novel anti-hiv protein isolated and characterized from a cyanobacterium nostoc ellipsosporum. cv-n protein is a single 101 amino acid chain containing two intrachain disulphide bonds and considerable internal sequence duplication, but no significant homology to previously described proteins or to the transcription products of known nucleotide sequences. in solution, cv-n exists largely as a beta-sheet protein with internal two-fold pseudosymmetry. cv-n irreversibly inact ... | 2000 | 10794101 |
| cyanobacterial diversity in geographically related and distant host plants of the genus gunnera. | the diversity among 45 cyanobacterial isolates from 11 different gunnera species originating from different geographical areas was examined. by means of polymerase chain reaction (pcr) fingerprinting with short tandemly repeated repetitive (strr) sequences as primers, ten groups of symbiotic cyanobacteria and five unique isolates not belonging to a particular group were identified. most groups were restricted to one geographical area, indicating a limited distribution of related cyanobacterial s ... | 2000 | 10795680 |