Publications

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on carrageen (chondrus crispus). ii: on the occurrence of ethereal sulphates in the plant. 192116743011
on carrageen (chondrus crispus). iii: the constitution of the cell wall. 192216743120
on carrageen (chondrus crispus): the hydrolysis of carrageen mucilage. 192916744227
some properties of the polysaccharide complex extracted from a marine alga, chondrus crispus. 193416745459
a note on the nitrogen of the polysaccharide complex from chondrus crispus. 193516745757
seasonal variations in chondrus crispus. 193616746163
2-keto-d-gluconic acid in the polysaccharide of irish moss. 194620989466
2-keto-d-gluconic acid in the polysaccharide of irish moss. 194621064272
a method of measuring the stabilizing power of extracts of irish moss. 194621015724
the effect of solvent and temperature on the viscosity of the polysaccharide or irish moss and the effect of solvent on its initial gelation. 194621015723
effect of processing and storage on the quality of gelose from irish moss (chondrus crispus). 194818916788
amino acids, peptides, and proteins of irish moss, chondrus crispus. 195813563510
sterols in irish moss (chondrus crispus). 19665968606
heterogeneity of carrageenans from chondrus crispus.carrageenans extracted from gametophytic and sporophytic chondrus crispus were analysed by hydrolysis, kcl fractionation and 1h nmr spectroscopy. the carrageenan from gametophytic plants is composed predominantly of two kcl insoluble fractions which contain kappa-carrageenan as the major component with 1-carrageenan and sulphated galactans as minor components. the precursor mu- and v-carrageenans were not found in the soluble fraction. the extract from sporophytic plants is composed mainly of a ...19701367970
plasmalemmal extensions in chondrus crispus (l.) stackh. 19714329670
the incorporation of s-labeled sulfate into carrageenan in chondrus crispus. 197116657801
carrageenans in the gametophytic and sporophytic stages of chondrus crispus.the morphologically similar sporophytic and gametophytic plants of chondrus crispus stackhouse were examined and it was shown that the former contain λ-carrageenan. the gametophytes contain ϰ- and two additional carrageenans which are kcl-soluble and may comprise up to 25% of the total carrageenan. after alkaline modification, these kcl-soluble components were separated into a gel and a soluble carrageenan. the gel was indistinguishable from ϰ-carrageenan and presumably was derived from μ-carrag ...197324468729
purification and characterization of hexose oxidase from the red alga chondrus crispus. 19734708670
h(2) metabolism in photosynthetic organisms: i. dark h(2) evolution and uptake by algae and mosses.dark h(2) metabolism was studied in marine and fresh water red algae, the green alga, chlamydomonas, and mosses. a time variable and temperature-sensitive anaerobic incubation was required prior to h(2) evolution. h(2) evolution was sensitive to disalicylidenepropanediamine. an immediate h(2) uptake was observed in these algae. immediate dark h(2) uptake but no evolution was observed in the mosses.a cell-free hydrogenase preparation was obtained from anaerobically adapted chlamydomonas reinhardi ...197516659260
the occurrence and seasonal variation of gigartinine and l-citrullinyl-l-arginine in chondrus crispus stackh.gigartinine, 5-(3-amidinoureido)-2-aminovaleric acid, and l-citrullinyl-l-arginine were islated from aqueous extracts of chondrus crispus (rhodophyceae). their identifications were confirmed by chemical procedures, and 1h and 13c nuclear magnetic resonance and infrared spectroscopic methods. citrullinylarginine, gigartinine, taurine, citrulline, and glutamic acid were the predominant free amino compounds. citrullinylarginine showed the most pronounced change in concentration. this occurred durin ...1977837242
sulfohydrolase activity and carrageenan biosynthesis in chondrus crispus (rhodophyceae).an enzyme catalyzing the conversion of mu- to kappa-carrageenan has been demonstrated in both haploid and diploid plants of chondrus crispus. it acts at the polymer level producing 3,6-anhydro-d-galactose with the stoichiometric release of sulfate. two-thirds of the recoverable enzyme was associated with the 15,000g pellet most of which could be solubilized by passage through a ribi cell fractionator. the enzyme precipitated between 2.65 and 4.24 m (nh(4))(2)so(4) and was partly purified on deae ...197816660358
the immunochemistry of lambda-type carrageenans from certain red algae.an antibody preparation directed against a structural feature associated with 6-sulphate groups was used to probe structural relations among certain lambda-type carrageenans. immunochemical and chemical differences are described between the kc1-soluble carrageenans from tetrasporic algal plants of gigartina corymbifera, gigartina sp. from san francisco bay, petrocelis middendorfii, iridaea cordata, rhodoglossum californicum, and chondrus crispus. the differences in immunochemical reactivity of t ...1978568513
glycosulphatase from pseudomonas carrageenovora. purification and some properties.a glycosulphatase present in the soluble fraction of disrupted pseudomonas carrageenovora has been purified 500-fold by gel filtration on sephacryl s-200 and ion-exchange chromatography on deae-sepharose cl-6b. by dodecylsulphate/polyacrylamide gel electrophoresis the enzyme is practically homogeneous and has a molecular weight of 55 000. conditions of optimal sodium chloride concentration and ph at 25 degrees c were 0.25--0.50 mol dm-3 and ph 7.0 respectively. the purified enzyme was inhibited ...1979520310
incorporation of [s]sulfate and [c]bicarbonate into karyotype-specific polysaccharides of chondrus crispus.gametophytic and sporophytic tissues of chondrus crispus (stackhouse) cultured in vitro were labeled with (35)s and (14)c. the major sulfated polysccharides isolated from the two karyotypes were characterized by kci fractionation, immunoprecipitation, and infrared spectroscopy. reproducibility of data has been demonstrated by an experiment using gametophytic t(4) strain with five replicates per time point. the rate of sulfate uptake was similar in haploid and diploid plants from a given area cul ...197916661014
quantitative x-ray microanalysis of halogen elements in biological specimens.standards were prepared for quantitative x-ray microanalysis of the halogen elements cl, br and i in sections of resin embedded biological specimens. halogenated aromatic compounds were dissolved in resin, which subsequently was polymerized. homogeneity and stability of the standards were determined and found to be satisfactory. a general procedure of calculation of elemental concentrations according to the continuum method is given for the case that the specimen contains appreciable concentrati ...1979521320
apoflavodoxin aggregation following dissociation of flavin.flavodoxins were isolated for the cyanobacteria anacystis nidulans and nostoc strain mac, and from the red alga chondrus crispus, and apoflavodoxins prepared by five methods. gel electrophoretic studies showed that whereas the apoproteins of a. nudulans and nostoc strain mac were recovered in monomeric form, the removal of riboflavin 5'-phosphate from c. crispus flavodoxin resulted in extensive aggregation of the apoprotein. in extent and nature this aggregation differed with the dissociating ag ...19806774761
efficiency of ferredoxins and flavodoxins as mediators in systems for hydrogen evolution.1. the efficiencies of ferredoxins and flavodoxins from a range of sources as mediators in systems for hydrogen evolution were assessed. 2. in supporting electron transfer from dithionite to hydrogenase of the bacterium clostridium pasteurianum, highest activity was shown by the ferredoxin from the cyanobacterium chlorogloeopsis fritschii and flavodoxin from the bacterium megasphaera elsdenii. the latter was some twenty times as active as comparable concentrations of methyl viologen. ferredoxins ...19807016115
components of predation intensity in the low zone of the new england rocky intertidal region.predation intensity often increases along local gradients of decreasing environmental rigor. assuming factors such as productivity and heterogeneity do not change along such gradients, potential factors responsible for this pattern include: (1) increased effectiveness per individual predator, (2) increased numbers of individual predators, (3) increased numbers of predator species of the same general morphological attributes, and (4) increased numbers of predator species of different general morp ...198328310571
oxygen uptake and photosynthesis of the red macroalga, chondrus crispus, in seawater: effects of light and co(2) concentration.with an experimental system using mass spectrometry techniques and infra-red gas analysis of co(2) developed for aquatic plants, we studied the responses to various light intensities and co(2) concentrations of photosynthesis and o(2) uptake of the red macroalga chondrus crispus s. the co(2) exchange resistance at air-water interface which could limit the photosynthesis was experimentally measured. it allowed the calculation of the free dissolved co(2) concentration. the response to light showed ...198416663760
redox potentials of algal and cyanobacterial flavodoxins.the redox potentials of flavodoxins from the cyanobacteria synechococcus pcc 6301 (formerly anacystis nidulans) and nostoc strain mac, and from the red alga chondrus crispus, were determined by potentiometric titration. for the oxidized-semiquinone interconversion the potentials at ph 7.0 of the three flavodoxins were between -210 and -235 mv, and these were ph-dependent over the range ph 6.9-8.2. for the semiquinone-reduced interconversion the potentials of the cyanobacterial flavodoxins were c ...19846424653
continuous measurements of the free dissolved co(2) concentration during photosynthesis of marine plants: evidence for hco(3) use in chondrus crispus.an experimental system consisting of a gas exchange column linked to an assimilation chamber has been developed to record continuously the free dissolved co(2) concentration in seawater containing marine plants. from experiments performed on the red macroalga chondrus crispus (rhodophyta, gigartinales), this measurement is in agreement with the free co(2) concentration calculated from the resistance to co(2) exchanges in a biphasic system (gas and liquid) as earlier reported. the response time o ...198516664281
oxygen uptake and photosynthesis of the red macroalga, chondrus crispus, in seawater: effects of oxygen concentration.with an experimental system developed for aquatic plants using the mass spectrometry technique and infrared gas analysis of co(2), we studied the responses to various o(2) concentrations of gas exchanges with the red macroalga chondrus crispus s. the results were as follows. (a) irrespective of the co(2) concentration, net photosynthesis was o(2) sensitive with a 45 to 70% stimulation at 2% o(2). even with high co(2), a significant warburg effect was detected. (b) although photosynthesis was co( ...198516664280
[a potent inhibitor of bacterial growth from a seaweed, chondrus crispus]. 19863467264
dark respiration in the marine macroalga chondrus crispus (rhodophyceae).dark respiration in the red macroalga chondrus crispus was studied under a variety of conditions. the components of respiration were examined using selective inhibitors in order to characterise pathways of respiration and examine regulation of respiration in marine macroalgae.in comparison to respiration rates generally reported for higher-plant leaves and roots, the steady-state rate of o2 consumption by this alga, after 30 min dark pretreatment, was found to be quite low (three- to sixfold low ...198624232031
preferential photosynthetic uptake of exogenous hco(3) in the marine macroalga chondrus crispus.the rate of hco(3) (-) uptake by the red macroalga chondrus crispus has been investigated. unbalanced concentrations of free co(2) and hco(3) (-), generated by the photosynthetic activity, were detected in steady state conditions by using an exchange column apparatus linked to an assimilation chamber. observing the variations of this gradient as influenced by the time of seawater transit from the assimilation chamber towards the column allowed an experimental determination of: (a) the actual gra ...198616664721
carbonic anhydrase-dependent inorganic carbon uptake by the red macroalga, chondrus crispus.the rate of photosynthetic carbon uptake of chondrus crispus stack-house plants, at various co(2) concentrations and pretreated with carbonic anhydrase (ca) inhibitors, was determined using an air-suspension, differential infra-red gas analyzer technique. it was found that the ca inhibitors, acetazolamide, dextran-bound acetazolamide (dbi, which does not permeate cell membranes), and subtilisin (a protease that attacks the cell surface) inhibit photosynthetic carbon uptake in c. crispus. inhibit ...198716665329
on the nature of the oxygen uptake in the light by chondrus crispus. effects of inhibitors, temperature and light intensity.the nature of the different processes of o2 uptake involved in the light in the red macroalga chondrus crispus stackhouse (rhodophyta, gigartinales) was investigated. at limiting co2, inh (2.5 mm) did not alter the o2 uptake rate. glycolate was not excreted and did not accumulate within the cells. kcn reduced the rate of o2 uptake in the light by 76% at limiting co2 and by 43% at saturating co2, but caused > 95% inhibition of o2 evolution. dcmu (5 μm) totally blocked the photosynthetic electron ...198724435462
distribution of carbonic anhydrase in british marine macroalgae.thirty-four species of marine macroalgae from around st. andrews, scotland, have been assayed for their external activity and thirty-three species for their total activity of carbonic anhydrase. activity was detected in all the rhodophyta tested apart from chondrus crispus, but was absent in codium fragile, enteromorpha sp. and monostroma fuscum (chlorophyta), and alaria esculenta, laminaria digitata, l. saccharina and l. hyperborea (phaeophyta). total activity of carbonic anhydrase per unit fre ...198928312650
the amino acid sequence of a flavodoxin from the eukaryotic red alga chondrus crispus.the amino acid sequence of the constitutive flavodoxin from the red alga chondrus crispus was determined from the analyses of peptide fragments derived by enzymic digestions of the carboxymethylated protein. this is the first sequence reported for a flavodoxin from a eukaryote. the protein is composed of 173 amino acid residues and is a member of the longer-chain group of flavodoxins. the extent of sequence homology to the three other flavodoxins in the group for which sequences are available is ...19892597140
crystallization and preliminary x-ray diffraction studies of oxidized flavodoxin from chondrus crispus, a red alga.crystals of the oxidized form of flavodoxin from a red alga, chondrus crispus, have been grown in ammonium sulfate solution by the dialysis method. the crystals belong to the orthorhombic system, space group p2(1)2(1)2(1), with unit cell dimensions of a = 63.6, b = 48.8, and c = 56.8 a. the asymmetric unit contains one molecule of flavodoxin. the crystals diffract x-rays to about 2.0 a resolution and are stable to x-ray beams. the diffraction patterns changed significantly upon soaking the cryst ...19892732209
mechanism of photosynthetic carbon dioxide uptake by the red macroalga, chondrus crispus.the aim of this study was to determine how chondrus crispus, a marine red macroalga, acquires the inorganic carbon (c(i)) it utilizes for photosynthetic carbon fixation. analyses of c(i) uptake were done using silicone oil centrifugation (using multicellular fragments of thallus), infrared gas analysis, and gas chromatography. inhibitors of carbonic anhydrase (ca), the band 3 anion exchange protein and na(+)/k(+) exchange were used in the study. it was found that: (a) c. crispus does not accumul ...198916666552
protoplast production in chondrus crispus gametophytes (gigartinales, rhodophyta).protoplasts were isolated from female gametophytes of chondrus crispus (stackh.) using commercial cellulase and various carrageenases prepared from marine bacteria. depending on the nature of the donor tissue (apices or whole thallus, wild or cultivated strains), yields ranged from 1.0-8.5×10(8) protoplasts per gram of fresh tissue. preincubating the tissue with a potassium chelator, kryptofix 222, enhanced protoplast yields by 30-50 %. based on staining with fluorescein diacetate most protoplas ...199024232676
tertiary structure of oxidized flavodoxin from an eukaryotic red alga chondrus crispus at 2.35-a resolution. localization of charged residues and implication for interaction with electron transfer partners.the crystal structure of the oxidized form of a flavodoxin from an eukaryotic red alga, chondrus crispus, has been determined by multiple isomorphous replacement and anomalous scattering methods. a model of the 173 residues and flavin mononucleotide (fmn) has been refined by a restrained least squares method to a crystallographic r-factor of 22.6% using 6236 reflections between 6.0 and 2.35 a with f greater than 3 sigma f. this molecule has a sheet consisting of five parallel beta-strands with t ...19902394748
structure of the oxidized long-chain flavodoxin from anabaena 7120 at 2 a resolution.the structure of the long-chain flavodoxin from the photosynthetic cyanobacterium anabaena 7120 has been determined at 2 a resolution by the molecular replacement method using the atomic coordinates of the long-chain flavodoxin from anacystis nidulans. the structure of a third long-chain flavodoxin from chondrus crispus has recently been reported. crystals of oxidized a. 7120 flavodoxin belong to the monoclinic space group p2(1) with a = 48.0, b = 32.0, c = 51.6 a, and beta = 92 degrees, and one ...19921303762
crystal structure of oxidized flavodoxin from a red alga chondrus crispus refined at 1.8 a resolution. description of the flavin mononucleotide binding site.in order to describe the detailed conformation of the oxidized flavodoxin from a eukaryotic red alga, chondrus crispus, the crystal structure has been refined by a restrained least-squares method. the crystallographic r factor is 0.168 for 13,899 reflections with f greater than 2 sigma f between 6.0 and 1.8 a resolution. the refined model includes 173 amino acid residues, flavin mononucleotide (fmn) and 110 water molecules. the root-mean-square deviation in bond lengths from ideal values is 0.01 ...19921602481
the gapdh gene system of the red alga chondrus crispus: promoter structures, intron/exon organization, genomic complexity and differential expression of genes.our previous phylogenetic analysis based on cdna sequences of chloroplast and cytosolic glyceraldehyde-3-phosphate dehydrogenases (gapdh; genes gapa and gapc, respectively) of the red alga chondrus crispus suggested that rhodophytes and green plants are sister groups with respect to plastids and mitochondria and diverged at about the same time or somewhat later than animals and fungi. here we characterize the genomic sequences of genes gapc and gapa of c. crispus with respect to promotor structu ...19938260635
the evolutionary origin of red algae as deduced from the nuclear genes encoding cytosolic and chloroplast glyceraldehyde-3-phosphate dehydrogenases from chondrus crispus.algae are a heterogeneous group of photosynthetic eukaryotes traditionally separated into three major subdivisions: rhodophytes, chlorophytes, and chromophytes. the evolutionary origin of rhodophytes or red algae and their links to other photosynthetic and nonphotosynthetic eukaryotes have been a matter of much controversy and speculation. here we present the first cdnas of nuclear protein genes from red algae: those encoding cytosolic and chloroplast glyceraldehyde-3-phosphate dehydrogenases (g ...19948007000
confirmation by gas chromatography/mass spectrometry of two unusual trans-3-monoethylenic fatty acids from the nova scotian seaweeds palmaria palmata and chondrus crispus.the structures of two unusual fatty acids, the known trans-3-hexadecenoic acid and a novel trans-3-tetradecenoic acid, both isolated from the nova scotian seaweeds palmaria palmata and chondrus crispus, were positively identified. after the extraction of the total fatty acids by saponification, followed by methylation, the monoenoic trans fractions were isolated by thin-layer chromatography on silica gel impregnated with silver nitrate. the monoenoic trans fractions were derivatized with 2-amino ...19948090067
physical map and gene organization of the mitochondrial genome of chondrus crispus (rhodophyta, gigartinales).organellar dna, i.e. a mixture of plastid and mitochondrial dnas, was purified from the rhodophyte chondrus crispus and analysed with restriction endonucleases. mitochondrial dna fragments were identified by heterologous hybridization, cloned, mapped and partially sequenced. the mitochondrial genome of c. crispus consists of a 25.9 kb circular molecule on which twenty genes were localized. compared with other plant mitochondrial genomes, c. crispus mitochondrial dna appears as a relatively small ...19947948923
nucleotide sequence of the cox3 gene from chondrus crispus: evidence that uga encodes tryptophan and evolutionary implications.we present the nucleotide sequence of the gene encoding subunit 3 of cytochrome c oxidase in chondrus crispus, the first report on a mitochondrial gene from a red alga. amino acid alignment with homologous proteins shows that tryptophan is specified by uga, as in the mitochondrial code of most organisms other than green plants. however, phylogenetic analyses of cox3 amino acid and nucleotide sequences indicate that c. crispus cox3 is related to the green-plant mitochondrial lineage. no rna editi ...19948190631
dna sequence, structure, and phylogenetic relationship of the mitochondrial small-subunit rrna from the red alga chondrus crispus (gigartinales rhodophytes).the entire nucleotide sequence containing the small-subunit ribosomal rna gene (ssu rrna) from the mitochondrial genome of chondrus crispus was determined. to our knowledge, this is the first sequence of a mitochondrial 16s-like rrna from a red alga. the length of this gene is 1,376 nucleotides. its secondary structure was constructed and compared with other known secondary structures from eubacteria and from mitochondria of land plants, green and brown algae, and fungi. phylogenetic trees were ...19957666449
complete sequence of the mitochondrial dna of the rhodophyte chondrus crispus (gigartinales). gene content and genome organization.the complete nucleotide sequence of the circular mitochondrial (mt) dna from the red alga chondrus crispus was determined (25,836 nucleotides, a+t content 72.1%). fifty one genes were identified. they include genes encoding three subunits of the cytochrome oxidase (cox1 to 3), apocytochrome b (cob), seven subunits of the nadh dehydrogenase complex (nad1 to 6, nad4l), two atpase subunits (atp6 and atp9), three ribosomal rnas (rrn5, srn and lrn), 23 trnas and four ribosomal proteins (rps3, rps11, ...19957616569
structural features and phylogeny of the actin gene of chondrus crispus (gigartinales, rhodophyta).we have characterized the cdna and genomic sequences that encode actin from the multicellular red alga chondrus crispus. southern-blot analysis indicates that the c. crispus actin gene (chac) is present as a single copy. northern analysis shows that, like the gapa gene, the actin gene is well expressed in gametophytes but weakly in protoplasts. compared to actin genes of animals, fungi, green plants and oomycetes, that of c. crispus displays a higher evolutionary rate and does not show any of th ...19958590468
the marine red alga chondrus crispus has a highly divergent beta-tubulin gene with a characteristic 5' intron: functional and evolutionary implications.we characterized a nuclear gene and its corresponding cdna encoding beta-tubulin (gene tubb1) of the marine red alga chondrus crispus. the deduced tubb1 protein is the most divergent beta-tubulin so far reported with only 64 to 69% amino acid identity relative to other beta-tubulins from higher and lower eukaryotes. our analysis reveals that tubb1 has an accelerated evolutionary rate probably due to a release of functional constraints in connexion with a specialization of microtubular structures ...19957599316
uag is a sense codon in several chlorophycean mitochondria.the mitochondrial genetic code of those land plants and green algae that have been examined does not deviate from the universal one. a red alga, chondrus crispus, is the sole reported example throughout the algae that uses a deviant (non-universal) mitochondrial genetic code (uga=trp). we have analyzed 366-bp dna sequences of the gene for mitochondrial cytochrome oxidase subunit i (coxi) from ten chlorophyceaen algae, and detected 3-8 in-frame uag codons in the sequences of five species. compari ...19968662206
genes for two subunits of succinate dehydrogenase form a cluster on the mitochondrial genome of rhodophyta.mitochondrial dna from the unicellular rhodophyte cyanidium caldarium rk-1 and the multicellular chondrus crispus were isolated, cloned, and sequenced. two genes, sdhb and sdhc, that encode subunits of the succinate dehydrogenase, were identified by similarity. these genes form a cluster (sdhcb) in both red algae.19968821668
a 5 s rrna gene is present in the mitochondrial genome of the protist reclinomonas americana but is absent from red algal mitochondrial dna.except in the case of land plants, mitochondrial ribosomes apparently lack a 5 s rrna species, even though this small rna is a component of all prokaryotic, chloroplast and eukaryotic cytosol ribosomes. in plants, the mitochondrial 5 s rrna is encoded by mtdna and differs in sequence from the 5 s rrna specified by plant nuclear and chloroplast genomes. a distinctive 5 s rrna component has not been found in the mitochondrial ribosomes of non-plant eukaryotes and, with the notable exception of the ...19968800209
a deviant mitochondrial genetic code in prymnesiophytes (yellow-algae): uga codon for tryptophan.the sequence of a representative mitochondrial gene coxi, encoding cytochrome c oxidase subunit i, was determined in five species that cover all the orders of the prymnesiophyta with the exception of the pavlovales. through this analysis, we noticed that the 'stop' codon uga appears frequently and, specifically, at conserved tryptophan (trp) sites of the gene. we showed these sites were not edited in the corresponding mrna in one of these species, isochrysis galbana. therefore, it is most likely ...19979342410
hexose oxidase from the red alga chondrus crispus. purification, molecular cloning, and expression in pichia pastoris.hexose oxidase from chondrus crispus catalyzes the oxidation of a variety of mono- and disaccharides including d-glucose, d-galactose, maltose, and lactose. the enzyme has previously been partially purified and was reported to be a highly glycosylated, copper-containing protein with a relative molecular mass of approximately 130,000 (sullivan, j. d., and ikawa, m. (1973) biochim. biophys. acta 309, 11-22). we report here the purification to homogeneity of hexose oxidase from c. crispus. the puri ...19979111074
characterization of hexose oxidase from the red seaweed chondrus crispus.hexose oxidase from the red seaweed, chondrus crispus was purified to homogeneity. the enzyme appeared to be encapsulated in particles obtained after mechanical disintegration of the fronds. liberation of the enzyme in soluble form required either waiting for the spontaneous development of a suitable microbial flora in the suspension, or treatment with a mixture of proteases (pronase). as deduced from (sds/)page, the enzyme has a molecular mass of 87 kda and probably consists of subunits of 36 k ...19979108257
directionally evolving genetic code: the uga codon from stop to tryptophan in mitochondria.for the comprehensive analyses of deviant codes in protistan mitochondria (mt), we sequenced about a 1.1-kb region of a mitochondrial (mt) gene, the cytochrome c oxidase subunit i (coxi) in two chlorarachniophytes, the filose amoeba euglypha rotunda, the cryptomonad cryptomonas ovata, the prymnesiophyte (haptophyte) diacronema vlkianum (pavlovales), and the diatom melosira ambigua. as a result of this analysis, we noticed that the uga codon is assigned to tryptophan (trp) instead of being a sign ...19989767683
transcription initiation and rna processing in the mitochondria of the red alga chondrus crispus: convergence in the evolution of transcription mechanisms in mitochondria.the mitochondrial dna (mt dna) of the red alga chondrus crispus is shown to be transcribed into two large rna molecules. these primary transcripts are cleaved once, at the level of a trna, then the resulting products are processed via multiple maturation events into either mono- or poly-cistronic rnas. transcripts were detected for all genes and open reading frames, except for rps11 and orf172. for both transcription units the initiation of transcription was mapped by in vitro rna capping and pr ...19989784365
sulfated oligosaccharides mediate the interaction between a marine red alga and its green algal pathogenic endophyte.the endophytic green alga acrochaete operculata completely colonizes the sporophytes of the red alga chondrus crispus; however, it does not penetrate beyond the outer cell layers of the gametophytes. given that the life cycle phases of c. crispus differ in the sulfation pattern of their extracellular matrix carrageenans, we investigated whether carra-geenan fragments could modulate parasite virulence. lambda-carrageenan oligosaccharides induced release of h(2)o(2), stimulated protein synthesis, ...199910488232
mrna expression in mitochondria of the red alga chondrus crispus requires a unique rna-processing mechanism, internal cleavage of upstream trnas at pyrimidine 48.the hypothesis that trnas are involved in the maturation of the large primary transcripts of chondrus crispus mitochondrial dna was addressed by primer extension mapping of the transcript 5' ends of the ten genes that are preceded by trna genes in c. crispus mitochondrial genome. among the 12 trnas that were candidates as maturation signals, eight, namely trnaarg, trnalys, trnaasp, trnagln, trnatrp, trnaile, trnaphe and trnagly, were cleaved internally upon maturation of c. crispus mitochondrial ...199910329164
photoinhibition of photosynthesis in macrocystis pyrifera (phaeophyceae), chondrus crispus (rhodophyceae) and ulva lactuca (chlorophyceae) in outdoor culture systems.the effect of solar radiation on photosynthesis and chlorophyll fluorescence associated to photosystem ii (ps ii) was determined in the phaeophyta macrocystis pyrifera, the rhodophyta chondrus crispus and the chlorophyta ulva lactuca by oxygen evolution and pulse-amplitude-modulated (pam) fluorescence. the algae were maintained in 1.2 m3 outdoor tanks with constant aeration and at 8, 26 and 100% incident irradiance (e(o)). all three species showed a decrease in deltaf/f'm values during solar noo ...200011154083
drag, drafting, and mechanical interactions in canopies of the red alga chondrus crispus.dense algal canopies, which are common in the lower intertidal and shallow subtidal along rocky coastlines, can alter flow-induced forces in their vicinity. alteration of flow-induced forces on algal thalli may ameliorate risk of dislodgement and will affect important physiological processes, such as rates of photosynthesis. this study found that the force experienced by a thallus of the red alga chondrus crispus (stackhouse) at a given flow speed within a flow tank depended upon (1) the density ...200111687385
hexose oxidase from chondrus crispus: improved purification using perfusion chromatography(*).1an improved method for purifying hexose oxidase (d-hexose: o(2) 1-oxidoreductase, ec 1.1.3.5) from the marine red alga chondrus crispus is described for obtaining enzyme suitable for structural characterization and use in bioconversion of lactose to lactobionic acid. this involved extracting enzyme from finely ground lyophilized tissue in sodium phosphate buffer (ph 7) containing 20% ammonium sulfate, eliminating the previously used solvent extraction and protease treatments, and by applying po ...200111427234
on the structure of kappa/iota-hybrid carrageenans.the coil-to-helix transition and temperature dependence of the viscosity of commercial kappa/iota-hybrid carrageenans produced by the red algae sarcothalia crispata, mazaella laminarioides, and chondrus crispus were studied using rheometry and optical rotation. the structure of these kappa/iota-hybrid carrageenans was determined by 1h and 13c nmr spectroscopy combined with monosaccharide composition analysis. the coil-to-helix transitions, measured by polarimetry and rheometry, of the kappa/iota ...200111383897
optimization of the production of chondrus crispus hexose oxidase in pichia pastoris.hexose oxidase (d-hexose:o(2)-oxidoreductase, ec 1.1.3.5, hox) normally found in the red alga chondrus crispus was produced heterologously in different host systems. full-length hox polypeptide was produced in escherichia coli, but no hox activity could be detected. in contrast, active hox could be produced in the methylotrophic yeast pichia pastoris. several growth physiological and genetic approaches for optimization of hexose oxidase production in p. pastoris were investigated. our results in ...200111437594
a signal released by an endophytic attacker acts as a substrate for a rapid defensive reaction of the red alga chondrus crispus. 200212465036
effect of humic substances on cu(ii) solubility in kaolin-sand soil.the type and amount of organic matter present in industrially contaminated soils will influence the risk they pose. previous studies have shown the importance of humic and fulvic acids (fas) (important components of soil organic matter) in increasing the solubility of toxic metals but were not carried out using toxic metal levels and the ph range typical of industrially contaminated soils. this study investigated the influence of three humic substances (hss: humates, fulvates and humins) on the ...200212220826
capacity of edible seaweeds to modify in vitro starch digestibility of wheat bread.the capacity of two species of edible seaweeds (wakame, undaria pinnatifida and chondrus, chondrus crispus) to modify the rate of white bread starch digestibility by an in vitro digestion system, as well as glucose retardation index and apparent viscosity were studied. both algae showed different effect on glucose retardation index. while wakame did not make difficult dialysis of glucose, it only retained 2.50 +/- 2.99% to respect a negative control. chondrus impaired the diffusion of a 28.70 +/ ...200211890047
use of ftir, ft-raman and 13c-nmr spectroscopy for identification of some seaweed phycocolloids.many seaweeds produce phycocolloids, stored in the cell wall. members of the rhodophyceae produce polysaccharides the main components of which are galactose (galactans)-agar and carrageenan. in addition, alginic acid is extracted from members of the phaeophyceae. this is a binary polyuronide made up of mannuronic acid and guluronic acid. the wide uses of these phycocolloids are based on their gelling, viscosifying and emulsifying properties, which generate an increasing commercial and scientific ...200312919801
carrageenophytes of occidental portuguese coast: 1-spectroscopic analysis in eight carrageenophytes from buarcos bay.infrared and raman spectroscopic analysis of the carrageenan (alkaline extraction) in eight species (representing seven genera and four families) of gigartinales, in different reproductive phases from buarcos bay (figueira da foz, portugal), were studied. female gametophytes and non-fertile thalli samples of chondrus crispus, mastocarpus stellatus, chondracanthus teedei var. lusitanicus, gigartina pistillata and chondracanthus acicularis present a kappa-carrageenan profile or varying degrees of ...200312919800
safety evaluation of a hexose oxidase expressed in hansenula polymorpha.a programme of studies was conducted to establish the safety of hexose oxidase (hox) from chondrus crispus expressed in the yeast hansenula polymorpha to be used as a processing aid in the food industry. rat feeding studies were conducted to assess acute and subchronic oral toxicity. in addition, the potential of the enzyme to cause mutagenicity and chromosomal aberrations was assessed in microbial and tissue culture in vitro studies. acute and subchronic oral toxicity was not detected at the hi ...200312615123
analysis and modeling of the ferulic acid oxidation by a glucose oxidase-peroxidase association. comparison with a hexose oxidase-peroxidase association.a commercial glucose oxidase (gox) from aspergillus niger was partially characterized. the enzyme exhibited a two-step transfer mechanism, and the kinetic constants toward glucose and oxygen were determined. under conditions similar to dough making (glucose concentration and ph), gox does not exhibit maximum activity. a hexose oxidase (hox) from chondrus crispus was partially characterized as well. the hox activity is not far from the optimum in the kneading conditions (ph and glucose concentrat ...200415186121
evaluation of heat shock protein 70 as a biomarker of environmental stress in fucus serratus and lemna minor.heat shock proteins (hsps) are known to be induced in response to short-term stress. the present study aimed to evaluate the potential of hsp70 as a biomarker of stress produced by increased temperature, osmotic pressure, and exposure to cadmium and sodium chloride in marine macroalgae and fresh water plant species. an indirect competitive enzyme-linked immunosorbent assay (ic-elisa) was developed with a working range of 0.025-10 microg ml(-1) using a monoclonal antibody raised against purified ...200415370872
seasonal acclimatization of antioxidants and photosynthesis in chondrus crispus and mastocarpus stellatus, two co-occurring red algae with differing stress tolerances.mastocarpus stellatus and chondrus crispus are red macroalgae that co-dominate the lower rocky intertidal zones of the northern atlantic coast. m. stellatus is more tolerant than c. crispus of environmental stresses, particularly those experienced during winter. this difference in tolerance has been attributed, in part, to greater contents or activities of certain antioxidants in m. stellatus. we compared the photosynthetic capacities and activities of three antioxidant enzymes--superoxide dismu ...200415616353
a monochromatic action spectrum for the photoinduction of the uv-absorbing mycosporine-like amino acid shinorine in the red alga chondrus crispus.to determine the action spectrum for photoinduction of the ultraviolet (uv)-absorbing mycosporine-like amino acid shinorine, specimens of the marine red alga chondrus crispus were irradiated with monochromatic light of various wavelengths using the okazaki large spectrograph at the national institute for basic biology, okazaki, japan. fluence response curves were determined for the wavelengths between 280 and 750 nm, by irradiating the algae with monochromatic light for 10 h, followed by 4 h of ...200415291302
the innate immunity of a marine red alga involves oxylipins from both the eicosanoid and octadecanoid pathways.the oxygenated derivatives of fatty acids, known as oxylipins, are pivotal signaling molecules in animals and terrestrial plants. in animal systems, eicosanoids regulate cell differentiation, immune responses, and homeostasis. in contrast, terrestrial plants use derivatives of c18 and c16 fatty acids as developmental or defense hormones. marine algae have emerged early in the evolution of eukaryotes as several distinct phyla, independent from the animal and green-plant lineages. the occurrence o ...200415247395
apoplastic oxidation of l-asparagine is involved in the control of the green algal endophyte acrochaete operculata correa & nielsen by the red seaweed chondrus crispus stackhouse.gametophytes of the marine alga chondrus crispus are more resistant than tetrasporophytes to infection by the filamentous endophytic alga acrochaete operculata. it has been shown recently that carrageenan oligosaccharides from the resistant gametophytic generation of c. crispus stimulate the secretion of l-asparagine (l-asn) by the endophyte and that the host generates hydrogen peroxide and 2-oxo-succinamic acid after contact with this amino acid. here the response of c. crispus to l-asn and its ...200515784529
uptake and depuration of 131i by the edible periwinkle littorina littorea: uptake from labelled seaweed (chondrus crispus).uptake and depuration experiments of (131)i from labelled seaweed (chondrus crispus) by the edible periwinkle littorina littorea have been performed. radioiodine concentrations in winkles during uptake followed first-order kinetics with an uptake half-time of 1 day, and a calculated equilibrium concentration (c(infinity)) of 21 000 bq kg(-1) resulting in a transfer factor of 0.07 with respect to the labelled seaweed used as food. for depuration, a biphasic sequence with biological half-lives of ...200515725502
uptake and depuration of 131i by the edible periwinkle littorina littorea: uptake from seawater.uptake and depuration experiments for the edible periwinkle littorina littorea have been performed using 131i-labelled seawater. throughout the experimental phase the winkles were fed on unlabelled chondrus crispus. 131i concentrations in winkles during uptake followed linear first-order kinetics with an uptake half-time of 11 days, whereas for depuration a triphasic sequence with biological half-lives of 4, 23 and 56 days was determined. in general, iodine turnover in winkles via labelled seawa ...200515465179
evaluation of certain food additives.this report represents the conclusions of a joint fao/who expert committee convened to evaluate the safety of various food additives, with a view to recommending acceptable daily intakes (adis) and to prepare specifications for the identity and purity of food additives. the first part of the report contains a general discussion of the principles governing the toxicological evaluation of food additives (including flavouring agents) and contaminants, assessments of intake, and the establishment an ...200516167501
characterization of the flavin association in hexose oxidase from chondrus crispus.hexose oxidase (ec 1.1.3.5) from hansenula polymorpha was found to exhibit a dual covalent association of fad with his79 via an 8 alpha-histidyl linkage as well as a covalent association between cys138 and c-6 of the isoalloxazine moiety of fad. spectral properties of the wild-type enzyme exhibited maxima at 364 nm and 437 nm as well as a distinct shoulder at 445 nm. an h79k mutant enzyme exhibited only one maximum at 437 nm. the difference absorption spectrum between an oxidized and a substrate ...200616817897
expression profiling of chondrus crispus (rhodophyta) after exposure to methyl jasmonate.methyl jasmonate (meja) is a plant hormone important for the mediation of signals for developmental processes and defence reactions in higher plants. the effects of meja and the signalling pathways on other photosynthetic organism groups are largely unknown, even though meja may have very important roles. therefore the effects of meja in a red alga were studied. a medium-scale expression profiling approach to identify genes regulated by meja in the red seaweed chondrus crispus is described here. ...200617043086
the hydrodynamic effects of shape and size change during reconfiguration of a flexible macroalga.rocky intertidal organisms experience large hydrodynamic forces due to high water velocities created by breaking waves. flexible organisms, like macroalgae, often experience lower drag than rigid organisms because their shape and size change as velocity increases. this phenomenon, known as reconfiguration, has been previously quantified as vogel's e, a measure of the relationship between velocity and drag. while this method is very useful for comparing reconfiguration among organisms it does not ...200616651555
nadph oxidases in eukaryotes: red algae provide new hints!the red macro-alga chondrus crispus is known to produce superoxide radicals in response to cell-free extracts of its green algal pathogenic endophyte acrochaete operculata. so far, no enzymes involved in this metabolism have been isolated from red algae. we report here the isolation of a gene encoding a homologue of the respiratory burst oxidase gp91(phox) in c. crispus, named ccrboh. this single copy gene encodes a polypeptide of 825 amino acids. search performed in available genome and est alg ...200616344959
analysis of expressed sequence tags from the red alga griffithsia okiensis.red algae are distributed globally, and the group contains several commercially important species. griffithsia okiensis is one of the most extensively studied red algal species. in this study, we conducted expressed sequence tag (ests) analysis and synonymous codon usage analysis using cultured g. okiensis samples. a total of 1,104 cdna clones were sequenced using a cdna library made from samples collected from dolsan island, on the southern coast of korea. the clustering analysis of these seque ...200718176538
response of the transcriptome of the intertidal red seaweed chondrus crispus to controlled and natural stresses.intertidal seaweeds inhabit an inherently stressful environment with rapidly changing physical conditions with the turning tides. many macroalgae are therefore very resistant to abiotic stress; however, the bases for this tolerance and the relative importance of different stressors are largely unknown. here, the effects of stress on the transcriptome of the red seaweed chondrus crispus were investigated using cdna microarrays. the responses were studied after exposure to high light, high tempera ...200717803640
evidence for oxylipin synthesis and induction of a new polyunsaturated fatty acid hydroxylase activity in chondrus crispus in response to methyljasmonate.signaling cascades involving oxygenated derivatives (oxylipins) of polyunsaturated fatty acids (pufas) are known to operate in response to external stimuli. the marine red alga chondrus crispus uses both oxygenated derivatives of c18 (octadecanoids) and c20 (eicosanoids) pufas as developmental or defense hormones. the present study demonstrates that methyljasmonate (meja) triggers a cascade of oxidation of pufas leading to the synthesis of prostaglandins and other oxygenated fatty acids. as a re ...200717428728
new members of the glutathione transferase family discovered in red and brown algae.the gsts (glutathione transferases) are involved in the detoxification of a wide variety of hydrophobic substrates. these enzymes have been found in virtually all types of organisms, including plants, animals, nematodes and bacteria. in the present study, we report the molecular and biochemical characterization of algal gsts. phylogenetic analysis showed that most of them were distinct from previously described gst classes, but were most closely related to the sigma class. profiling of gst genes ...200818315526
composition and distribution of carrabiose moieties in hybrid kappa-/iota-carrageenans using carrageenases.hybrid kappa/iota-carrageeans extracted from gigartina skottsbergii, chondracanthus chamissoï, and chondrus crispus were incubated with pseudoalteromonas carrageenovora kappa-carrageenase and alteromonas fortis iota-carrageenase. the degradation products as well as the resistant fraction were fully characterized by chromatography, nmr, and mass spectrometry. the low percentage of degradation observed after treatment by the iota-carrageenase suggests that long segments of iota-carrabiose or block ...200818081251
conformational changes in chondrus crispus flavodoxin on dissociation of fmn and reconstitution with flavin analogues.the apoflavodoxin produced by precipitation of chondrus crispus flavodoxin with trichloroacetic acid migrates as a single molecular species on non-denaturing page, but at a much lower rm than the flavoprotein. values of s and d were significantly lower than for the flavodoxin, but their substitution in the svedberg equation indicated the molecular mass was closely similar to that of the flavodoxin. this was confirmed by meniscus-depletion sedimentation-equilibrium studies. the stokes radius of t ...20082268302
the cyclization of the 3,6-anhydro-galactose ring of iota-carrageenan is catalyzed by two d-galactose-2,6-sulfurylases in the red alga chondrus crispus.carrageenans are sulfated galactans found in the cell walls of numerous red seaweeds (rhodophyta). they are classified according to the number and the position of sulfate ester groups and the occurrence of 3,6-anhydro-galactose. although the carrageenan biosynthesis pathway is not fully understood, it is usually accepted that the last step consists of the formation of a 3,6-anhydro ring found in kappa- and iota-carrageenans through the enzymatic conversion of d-galactose-6-sulfate or d-galactose ...200919734263
postharvest culture in the dark: an eco-friendly alternative to alkali treatment for enhancing the gel quality of kappa/iota-hybrid carrageenan from chondrus crispus (gigartinales, rhodophyta).after harvesting from natural stocks, female gametophytes of the red seaweed chondrus crispus were cultured for several days under a light-deprived regime in order to determine if dark treatment can improve the gel quality of carrageenan extracted from the seaweed. an increase in the gel strength of native carrageenan was observed after dark treatment for 10d, but not after 5d, as compared to that of freshly harvested (baseline) seaweed. corresponding decrease in sulfate and increase in 3,6-anhy ...200919138513
tracing back efl gene evolution in the cryptomonads-haptophytes assemblage: separate origins of efl genes in haptophytes, photosynthetic cryptomonads, and goniomonads.a recently identified gtpase, elongation factor-like (efl) protein is proposed to bear the principal functions of translation elongation factor 1alpha (ef-1alpha). pioneering studies of ef-1alpha/efl evolution have revealed the phylogenetically scattered distribution of efl amongst eukaryotes, suggesting frequent eukaryote-to-eukaryote efl gene transfer events and subsequent replacements of ef-1alpha functions by efl. we here determined/identified seven new efl sequences of the photosynthetic cr ...200918585873
chlorophyll-binding proteins revisited--a multigenic family of light-harvesting and stress proteins from a brown algal perspective.chlorophyll-binding proteins (cbps) constitute a large family of proteins with diverse functions in both light-harvesting and photoprotection. the evolution of cbps has been debated, especially with respect to the origin of the li818 subfamily, members of which function in non-photochemical quenching and have been found in chlorophyll a/c-containing algae and several organisms of the green lineage, but not in red algae so far. the recent publication of the ectocarpus siliculosus genome represent ...201021110855
sensitivity of the early life stages of macroalgae from the northern hemisphere to ultraviolet radiation.the reproductive cells of macroalgae are regarded as the life history stages most susceptible to various environmental stresses, including uv radiation (uvr). uvr is proposed to determine the upper depth distribution limit of macroalgae on the shore. these hypotheses were tested by uv-exposure experiments, using spores and young thalli of the eulittoral rhodophyceae mastocarpus stellatus and chondrus crispus and various sublittoral brown macroalgae (phaeophyceae) with different depth distributio ...201017645656
polyunsaturated fatty acids in various macroalgal species from north atlantic and tropical seas.in this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated.201121696609
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