| endo-beta-n-acetylglucosaminidase from streptomyces plicatus. | | 1978 | 26849 |
| purification and properties of endo-beta-n-acetylglucosaminidase l from streptomyces plicatus. | an enzyme, previously described as endo-beta-n-acetylglucosaminidase l (tarentino, a.l., and maley, f. (1974) j. biol. chem. 249, 811-817) because of its apparent specificity for man(glcnac)2asn, has been purified to homogeneity. the enzyme has now been found to hydrolyze (glcnac)3 to (glcnac)2 plus glcnac, and (glcnac)4 to 2(glcnac)2, at twice the rate observed for man(glcnac)2asn. removal of the asparagine from the latter compound reduces the rate of hydrolysis by about 30-fold. reduction of ( ... | 1979 | 489563 |
| a rapid semiquantitative assay that facilitates purification of endo-beta-n-acetylglucosaminidase h from streptomyces plicatus. | | 1978 | 626379 |
| norplicacetin, a new antibiotic from streptomyces plicatus. | | 1977 | 893228 |
| purification and properties of an endo-beta-n-acetylglucosaminidase from hen oviduct. | an endo-beta-n-acetylglucosaminidase has been purified extensively from hen oviduct extracts and found to have a somewhat broader substrate specificity than the previously reported endoglycosidases from dipolcoccus pneumoniae and streptomyces plicatus (arakawa, m., and muramatsu, t. (1974) j. biochem. (tokyo) 76, 307-317; tarentino, a. l., and maley, f. (1975) biochem. biophys. res. commun. 67, 455-462. the enzyme was shown to hydrolyze and di-n-acetylchitobiosyl bond in such compounds as asn(gl ... | 1976 | 977586 |
| direct repeat sequences are implicated in the regulation of two streptomyces chitinase promoters that are subject to carbon catabolite control. | we report the identification and partial characterization of the promoters for two chitinase genes from streptomyces plicatus. chitinases are a family of enzymes made by streptomyces and other soil microbes to digest chitin, an abundant source of carbon and nitrogen in the soil. the promoter regions of two chitinases were defined by using transcriptional fusions to the xyle reporter gene. transcription was shown to be glucose-sensitive and chitin-dependent. each promoter contains a putative rna ... | 1992 | 1542688 |
| structure of the gene encoding chitinase d of bacillus circulans wl-12 and possible homology of the enzyme to other prokaryotic chitinases and class iii plant chitinases. | the gene (chid) encoding the precursor of chitinase d was found to be located immediately upstream of the chia gene, encoding chitinase a1, which is a key enzyme in the chitinase system of bacillus circulans wl-12. sequencing analysis revealed that the deduced polypeptide encoded by the chid gene was 488 amino acids long and the distance between the coding regions of the chia and chid genes was 103 bp. remarkable similarity was observed between the n-terminal one-third of chitinase d and the c-t ... | 1992 | 1729234 |
| multiple endoglycosidase (endo) f activities expressed by flavobacterium meningosepticum. endo f1: molecular cloning, primary sequence, and structural relationship to endo h. | a full-length insert for the endo-beta-n-acetylglucosaminidase (endo) f1 gene was located on a 2,200-base pair ecori fragment of genomic dna and cloned into the plasmid vector bluescript. transformed escherichia coli cells expressed endo f1 activity very well, but the enzyme apparently was not processed and secreted into the medium as it normally is in flavobacterium meningosepticum. dna sequencing revealed an open reading frame of 1,017 nucleotides encoding a putative 50-amino acid signal seque ... | 1992 | 1740434 |
| isolation of two endo-beta-n-acetylglucosaminidases with different specificities from pseudomonas sp. | two endo-beta-n-acetylglucosaminidases (pi and pii) have been isolated from the culture fluid of pseudomonas sp. the substrate specificity of the pi enzyme was very similar to that of endo-h from streptomyces plicatus. on the contrary, the pii enzyme had a novel substrate specificity that degraded both high-mannose type and hybrid type oligosaccharides derived from ovalbumin, and the core structure of complex type oligosaccharides derived from human transferrin and porcine pancreatic lipase. | 1991 | 1776950 |
| identification of distinct endoglycosidase (endo) activities in flavobacterium meningosepticum: endo f1, endo f2, and endo f3. endo f1 and endo h hydrolyze only high mannose and hybrid glycans. | flavobacterium meningosepticum endo-beta-acetyl-glucosaminidase f preparations have been resolved by hydrophobic interaction chromatography on tsk-butyl resin into at least three activities designated endo f1, endo f2 and endo f3 each with a unique substrate specificity. the 32-kda endo f1 protein is the principle component representing in excess of 95% of most earlier and currently available commercial endoglycosidase preparations, the remainder being a mixture of five proteins from 32 to 43 kd ... | 1991 | 1899092 |
| weak sequence homologies among chitinases detected by clustering analysis. | the amino acid sequences of various endo-n-acetyl-glucosaminidases (chitinases) have been subjected to hydrophobic cluster analysis. a domain of approximately 145 residues was found to be weakly conserved in chitinase a and b from the bacterium serriata marcescens, in a chitinase from cucumber (cucumis sativis) and in the endo-n-acetyl-glucosaminidase h of streptomyces plicatus. a prediction of the putative active site region was made upon analysis of invariant acidic amino acids. on the basis o ... | 1990 | 2089379 |
| purification of endo-n-acetyl-beta-d-glucosaminidase h by substrate-affinity chromatography. | endo-n-acetyl-beta-d-glucosaminidase h (endo h) was purified to homogeneity (3000-fold) from a culture filtrate to streptomyces plicatus. the key step was substrate-affinity chromatography, which afforded a 1000-fold purification and yielded a protease- and exoglycosidase-free preparation of endo h. proteins from the crude sample were applied to the substrate-affinity column, consisting of yeast-invertase glycopeptides bound to sepharose-immobilized concanavalin a. after washing off the unbound ... | 1989 | 2505925 |
| endo-beta-n-acetylglucosaminidase h from streptomyces plicatus. | | 1987 | 3110549 |
| cloning and expression of a streptomyces plicatus chitinase (chitinase-63) in escherichia coli. | 4-methylumbelliferyl (4-mu) glycosides of n-acetylglucosamine oligosaccharides were used as substrates to detect expression of a streptomyces chitinase in escherichia coli. low levels of enzyme were detected when s. plicatus dna was cloned into a bacteriophage lambda vector (embl-4). subcloning into e. coli plasmids also gave low but detectable levels of enzyme expression. high level expression was achieved by resection of the cloned s. plicatus dna with bal31 followed by in-frame fusion to the ... | 1988 | 3275646 |
| cloning and nucleotide sequence of a cellulase gene, casa, from an alkalophilic streptomyces strain. | a gene encoding an endo-type semi-alkaline cellulase was cloned from an alkalophilic streptomyces strain in streptomyces lividans, and its nucleotide sequence was determined. downstream from the transcriptional start point, which was determined by high-resolution s1 mapping, an open reading frame of 388 amino acids (aa) was present. the n-terminal amino acid sequence of the mature enzyme determined by an edman degradation procedure suggested that the cellulase had an extraordinarily long leader ... | 1988 | 3410319 |
| amplified expression of streptomyces endo-beta-n-acetylglucosaminidase h in escherichia coli and characterization of the enzyme product. | the endo-beta-n-acetylglucosaminidase h (endo h) gene from streptomyces plicatus has been cloned into the escherichia coli plasmid pkc30 (shimatake, h., and rosenberg, m. (1981) nature 272, 128-132), thus placing expression of this gene under control of the strong lambda promoter pl. the construction, pkce3, which includes a properly positioned e. coli ribosome binding site from the lac operon (robbins, p.w., trimble, r. b., wirth, d.f., hering, c., maley, f. maley, g. f., das, r., gibson, b.w., ... | 1985 | 3921547 |
| expression of the streptomyces enzyme endoglycosidase h in escherichia coli. | endoglycosidase h is one of a large number of enzymes secreted by streptomyces plicatus and other streptomyces species. when the structural gene for this enzyme is introduced into escherichia coli attached to the plasmid pbr-322 or charon 4 phage, the enzyme is synthesized and is found in the periplasmic space, culture medium, and cells. attachment of the uv-5 lac promoter to a site in the plasmid adjacent to the streptomyces insert stimulates enzyme synthesis as much as 100-fold. this result de ... | 1981 | 6270125 |
| fermentation, isolation, characterization and structure of nitrosofungin. | the new antifungal agent nitrosofungin was isolated in high yields from a mixed culture of two organisms consisting of a bacterium of the genus alcaligenes (uc 9152) and streptomyces plicatus uc 8272. the bacterium produces the agent, the streptomycete enhances the production by providing a precursor or an inducer. nitrosofungin in high concentrations inhibits a broad variety of pathogenic fungi in vitro. the agent is relatively non-toxic in small laboratory animals and high blood levels are obt ... | 1983 | 6360971 |
| primary structure of the streptomyces enzyme endo-beta-n-acetylglucosaminidase h. | we report the dna and primary amino acid sequences of the streptomyces plicatus enzyme endo-beta-n-acetylglucosaminidase h. peptide sequence information was derived from enzyme isolated from streptomyces culture medium using a combination of mass spectrometric methods and conventional techniques, including edman degradation and carboxypeptidase y digestion. the dna sequence was determined by analysis of the endo-beta-n-acetylglucosaminidase h gene cloned into the escherichia coli plasmid pbr322 ... | 1984 | 6429133 |
| endo-beta-n-acetylglucosaminidase l from streptomyces plicatus. | | 1982 | 6808308 |
| crystal structure of endo-beta-n-acetylglucosaminidase h at 1.9 a resolution: active-site geometry and substrate recognition. | endo-beta-n-acetylglucosaminidase h (endo h), an endoglycosidase secreted by streptomyces plicatus, hydrolyzes the glycosidic bond between the core n-acetyglucosamine residues of asparagine-linked high-mannose oligosaccharides. endo h is a commonly used reagent in glycobiology research, including the characterization of oligosaccharides in glycoproteins. on-going crystallographic studies of endo h and related endoglycosidases are aimed at identifying the molecular features that determine the dif ... | 1995 | 7663942 |
| identification of two aspartates and a glutamate essential for the activity of endo-beta-n-acetylglucosaminidase h from streptomyces plicatus. | in order to identify groups essential for the activity of endo-beta-n-acetylglucosaminidase h (endo h), all 8 glutamate residues, all 19 aspartates, and both tryptophans were individually substituted with glutamines, asparagines, and phenylalanines, respectively, by oligonucleotide site-directed mutagenesis. only variants d170n, d172n, and e174q were found to have specific activities significantly less than wild-type endo h. another variant, d173n, did not produce detectable amounts of protein. ... | 1994 | 7911292 |
| a proposed structure for 'family 18' chitinases. a possible function for narbonin. | the sequence of narbonin, a leguminous seed protein with the tim barrel structure but of unknown function, is significantly similar to endo-beta-n-acetylglucosaminidase h from streptomyces plicatus. this protein is a member of a family of chitinases, 'family 18' of the glycosyl hydrolases. it is proposed that the catalytic domain of this family has the tim barrel structure. it is proposed that narbonin has chitinase activity, or has been derived from a chitinase by loss of function. | 1994 | 7957898 |
| a new class of tobacco chitinases homologous to bacterial exo-chitinases displays antifungal activity. | a novel chitinase gene of tobacco was isolated and characterized by dna sequence analysis of a genomic clone and a cdna clone. comparative sequence analysis of both clones showed an identity of 94%. the proteins encoded by these sequences do not correspond to any of the previously characterized plant chitinases of classes i-iv and are designated as class v chitinases. comparison of the chitinase class v peptide sequence with sequences in the swiss protein databank revealed significant sequence s ... | 1994 | 8012401 |
| isolation and sequence of an endochitinase-encoding gene from a cdna library of trichoderma harzianum. | there are no reports of gene sequences coding for extracellular chitinolytic enzymes from filamentous fungi, even though these enzymes are considered critical to the biological control of plant pathogenic fungi. the purpose of this paper was to report the isolation of a gene (then-42) encoding endochitinase (ech) from trichoderma harzianum strain p1, describe its sequence, and to determine whether it was related to genes coding for enzymes with similar functions from prokaryotic or other eukaryo ... | 1994 | 8125293 |
| cloning and characterization of a potentially protective chitinase-like recombinant antigen from wuchereria bancrofti. | while there is no direct evidence demonstrating the existence of protective immunity to wuchereria bancrofti infection in humans, the presence of individuals, in populations in areas where infection is endemic, with no clinical evidence of past or current infection despite appreciable exposure to the infective larvae, suggests that protective immunity to filarial parasites may occur naturally. earlier work indicated that such putatively immune individuals generated antibodies to a 43-kda antigen ... | 1994 | 8168956 |
| cloning and sequence analysis of the gene encoding a thermostable chitinase from streptomyces thermoviolaceus opc-520. | the gene (chi40) encoding a thermostable chitinase from streptomyces thermoviolaceus opc-520 was cloned in escherichia coli jm109 using puc18. the nucleotide (nt) sequence of chi40 has been determined. a single open reading frame (orf) encoded a protein consisting of 414 amino acids (aa) with a m(r) of 43,838. the deduced aa sequence of the cloned chitinase (chi40) showed striking homology (74%) with chi63 from streptomyces plicatus. comparison with other chitinases revealed that chi40 contained ... | 1993 | 8244021 |
| structural and functional characterization of streptomyces plicatus beta-n-acetylhexosaminidase by comparative molecular modeling and site-directed mutagenesis. | we have sequenced the streptomyces plicatus beta-n-acetylhexosaminidase (sphex) gene and identified the encoded protein as a member of family 20 glycosyl hydrolases. this family includes human beta-n-acetylhexosaminidases whose deficiency results in various forms of gm2 gangliosidosis. based upon the x-ray structure of serratia marcescens chitobiase (smchb), we generated a three-dimensional model of sphex by comparative molecular modeling. the overall structure of the enzyme is very similar to h ... | 1998 | 9677388 |
| production of an endo-beta-n-acetylglucosaminidase activity mediates growth of enterococcus faecalis on a high-mannose-type glycoprotein. | enterococcus faecalis is associated with a high proportion of nosocomial infections; however, little is known of the ability of this organism to proliferate in vivo. the ability of rnase b, a model glycoprotein with a single n-glycosylation site occupied by a family of high-mannose-type glycans (man(5)- to man(9)-glcnac(2)), to support growth of e. faecalis was investigated. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of rnase b demonstrated a reduction in the molecular mass of thi ... | 2000 | 10648510 |
| identification of amino acid residues essential for the substrate specificity of flavobacterium sp. endo-beta-n-acetylglucosaminidase. | the gene encoding the endo-beta-n-acetylglucosaminidase from flavobacterium sp. (endo-fsp) was sequenced. the endo-fsp gene was overexpressed in escherichia coli cells, and was purified from inclusion bodies after denaturation by 8 m urea. the renatured endo-fsp had the same optimum ph and substrate specificity as the native enzyme. endo-fsp had 60% sequence identity with the endo-beta-n-acetylglucosaminidase from streptomyces plicatus (endo-h), and the putative catalytic residues were conserved ... | 2001 | 11515537 |
| streptomyces plicatus as a model biocontrol agent. | three hundred and seventy two isolates belonging to the genus streptomyces were isolated and screened for chitinase production. streptomyces plicatus was found to be the best producer. the highest chitinase production were incubated for 3 d at 30 degrees c on buffered culture medium (ph 8.0) containing chitin plus sucrose and calcium nitrate as carbon and nitrogen sources. s. plicatus chitinase had a highly significant inhibitory effect on spore germination, germ tube elongation and radial growt ... | 2001 | 11830942 |
| microbial antibiotic production aboard the international space station. | previous studies examining metabolic characteristics of bacterial cultures have mostly suggested that reduced gravity is advantageous for microbial growth. as a consequence, the question of whether space flight would similarly enhance secondary metabolite production was raised. results from three prior space shuttle experiments indicated that antibiotic production was stimulated in space for two different microbial systems, albeit under suboptimal growth conditions. the goal of this latest exper ... | 2006 | 16091928 |
| synthesis and kinetic analysis of the n-acetylhexosaminidase inhibitor xylnac-isofagomine. | [reaction: see text] an efficient 10-step preparation from 4-methoxypyridine of (2r,3r,4r)-2-acetamido-3,4-dihydroxypiperidine ("xylnac-isofagomine") in optically active form is described. key steps include an enantioselective reduction with catecholborane/(s)-2-methyl-cbs-oxazaborolidine, and a stereoselective pseudo-glycosylation of lithium azide by a cyclic sulfite ester. the title compound showed a ki = 21 microm when evaluated against the n-acetyl-beta-hexosaminidase from streptomyces plica ... | 2005 | 16149804 |
| detailed comparative analysis of the catalytic mechanisms of beta-n-acetylglucosaminidases from families 3 and 20 of glycoside hydrolases. | beta-n-acetylglucosaminidases are commonly occurring enzymes involved in the degradation of polysaccharides and glycoconjugates containing n-acetylglucosamine residues. such enzymes have been classified into glycoside hydrolase families 3 and 20 and are believed to follow distinct chemical mechanisms. family 3 enzymes are thought to follow a standard retaining mechanism involving a covalent glycosyl enzyme intermediate while family 20 enzymes carry out a substrate-assisted mechanism involving th ... | 2005 | 16171396 |
| active-pocket size differentiating insectile from bacterial chitinolytic +¦-n-acetyl-d-hexosaminidases. | chitinolytic +¦-n-acetyl-d-hexosaminidase is a branch of the gh20 (glycoside hydrolase family 20) +¦-n-acetyl-d-hexosaminidases that is only distributed in insects and micro-organisms, and is therefore a potential target for the action of insecticides. pugnac [o-(2-acetamido-2-deoxy-d-glucopyransylidene)-amino-n-phenylcarbamate] was initially identified as an inhibitor against gh20 +¦-n-acetyl-d-hexosaminidases. so far no crystal structure of pugnac in complex with any gh20 +¦-n-acetyl-d-hexosam ... | 2011 | 21692744 |
| an endo-β-n-acetylglucosaminidase from enterococcus faecalis v583 responsible for the hydrolysis of high-mannose and hybrid-type n-linked glycans. | it has been demonstrated previously that enterococcus faecalis produces secreted endoglycosidases that enable the bacteria to remove n-linked glycans from glycoproteins. one enzyme potentially responsible for this activity is ef0114, comprising a typical gh18 endoglycosidase domain and a gh20 domain. we have analyzed the other candidate, ef2863, and show that this predicted single domain gh18 protein is an endo-β-n-acetylglucosaminidase. ef2863 hydrolyzes the glycosidic bond between two n-acetyl ... | 2011 | 22093069 |
| high-level expression of endo-β-n-acetylglucosaminidase h from streptomyces plicatus in pichia pastoris and its application for the deglycosylation of glycoproteins. | endo-β-n-acetylglucosaminidase h (endo h, ec3.2.1.96) is a glycohydrolase that is widely used in the study of glycoproteins. the present study aimed to assess the effect of high-level endo-β-n-acetylglucosaminidase h expression in pichia pastoris. the dna coding sequence of this enzyme was optimized based on the codon usage bias of pichia pastoris and synthesized through overlapping pcr. this novel gene was cloned into a phbm905a vector and introduced into pichia pastoris gs115 for secretary exp ... | 2015 | 25781897 |
| inhibition of glcnac-processing glycosidases by c-6-azido-nag-thiazoline and its derivatives. | nag-thiazoline is a strong competitive inhibitor of gh20 β-n-acetyl- hexosaminidases and gh84 β-n-acetylglucosaminidases. here, we focused on the design, synthesis and inhibition potency of a series of new derivatives of nag-thiazoline modified at the c-6 position. dimerization of nag-thiazoline via c-6 attached triazole linkers prepared by click chemistry was employed to make use of multivalency in the inhibition. novel compounds were tested as potential inhibitors of β-n-acetylhexosaminidases ... | 2014 | 24658571 |
| expression, purification, and characterization of endo-β-n-acetylglucosaminidase h using baculovirus-mediated silkworm protein expression system. | endo-β-n-acetylglucosaminidase (endo h) from streptomyces plicatus hydrolyzes the core di-glcnac units of asparagine-linked oligosaccharides and is regarded as an important tool for glycobiology research. in the present study, we established a large-scale system to produce secreted endo h using a silkworm-baculovirus expression system (silkworm-bes). the recombinant endo h purified from silkworm hemolymph had activity comparable to that from recombinant escherichia coli. as well as its well-char ... | 2014 | 24599668 |
| correction: high-level expression of endo-β-n-acetylglucosaminidase h from streptomyces plicatus in pichia pastoris and its application for the deglycosylation of glycoproteins. | | 2015 | 26334882 |
| optimizing hydrolysis of n-linked high-mannose oligosaccharides by endo-beta-n-acetylglucosaminidase h. | the ability of endo-beta-acetylglucosaminidase h (endo h) from streptomyces plicatus to hydrolyze high-mannose oligosaccharides from glycoproteins is influenced by numerous factors, including the tertiary structure of the substrate glycoproteins, the amount of endo h used, the time of incubation, and the presence or absence of reagents that affect protein configuration. endo h levels below 10 to 20 milliunits/ml may incompletely hydrolyze oligosaccharides, regardless of the incubation time, beca ... | 1984 | 6437277 |
| characterization of large oligosaccharide-lipids synthesized in vitro by microsomes from saccharomyces cerevisiae. | conditions are described for optimizing the synthesis of large oligosaccharide-lipids in microsomal preparations from saccharomyces cerevisiae. on incubating microsomes, with gdp-[14c]man, the major product obtained was man9glcnac2-p-p-dolichol, but when both gdp-[14c]man and udp-[3h]glc were present in the incubation mixture about half of the man9glcnac2 was elongated to glc3man9glcnac2-p-p-dolichol. unlike particulate fractions from mammalian systems, little glucosylation of the yeast microsom ... | 1980 | 6159353 |
| n-glycosylation of purified rat and rabbit hepatic udp-glucuronosyltransferases. | five udp-glucuronosyltransferases (udpgts) have been isolated to apparent homogeneity from rat and rabbit liver and have been characterized for their glycoprotein nature by reacting these proteins with commercially available endo- and exoglycosidases. the enzymes studied were rat hepatic p-nitrophenol, 17 beta-hydroxysteroid, and 3 alpha-hydroxysteroid udpgts and rabbit hepatic p-nitrophenol and estrone udpgts. hydrolysis of oligosaccharide moieties was evidenced by an increase in the mobility ( ... | 1989 | 2502948 |
| purification and properties of an iminopeptidase from culture media of streptomyces plicatus. | the degradation of the prosequence of the secreted enzyme endo-beta-n-acetylglucosaminidase h from streptomyces plicatus is not elucidated. both the primary structure of this segment and the finding that the secreted species contain ragged aminoterminal ends of specific structure suggested that a dipeptidylaminopeptidase might mature this enzyme. therefore, we tested the culture medium of streptomyces plicatus for prolin-specific peptidases. proline iminopeptidase was purified about 800-fold to ... | 1992 | 1590787 |
| cloning and high-level expression of chitinase-encoding gene of streptomyces plicatus. | a chitinase (cht)-encoding gene from streptomyces plicatus was previously cloned and expressed in escherichia coli [robbins et al., j. biol. chem., 263 (1988) 442-447]. we have sequenced this gene, compared its sequence with other genes encoding cht and have explored its expression and regulation when reintroduced into streptomyces lividans on multicopy plasmids. we have also cloned two other streptomyces cht-encoding genes and a beta-hexosaminidase-encoding gene in e. coli by expression in the ... | 1992 | 1532161 |
| glycoprotein nature of yeast alkaline phosphatase. formation of active enzyme in the presence of tunicamycin. | the nonspecific alkaline phosphatase of yeast (saccharomyces strain 1710) has been purified by ion exchange, hydrophobic, and affinity chromatography. this vacuolar enzyme has a molecular weight of 130,000 and is composed of subunits (probably of 66,000 molecular weight). it also has a small quantity of covalently associated carbohydrate; hydrolysis yielded mannose and glucosamine. the endo-beta-n-acetylglucosaminidase of streptomyces plicatus released carbohydrate indicating that the latter was ... | 1979 | 500684 |
| subunit structure of external invertase from saccharomyces cerevisiae. | because 50% of the mass of the external invertase of saccharomyces cerevisiae consists of carbohydrate, it has been extremely difficult to obtain an accurate molecular weight of this enzyme by centrifugal or electrophoretic techniques. however, on removing almost all of the oligosaccharide chains of this enzyme with the endo-beta-n-acetyl-glucosaminidase h from streptomyces plicatus, it has been possible to show that carbohydrate-free invertase is composed of two 60,000-dalton subunits. terminal ... | 1977 | 325007 |
| a remodeling system for the oligosaccharide chains on glycoproteins with microbial endo-beta-n-acetylglucosaminidases. | endo-m, endo-beta-n-acetylglucosaminidase from mucor hiemalis, transferred the complex type oligosaccharide of sialoglycopeptide to partially deglycosylated proteins (n-acetylglucosamine-attached proteins), which were prepared by excluding high-mannose type oligosaccharides from glycoproteins with endo-h, endo-beta-n-acetylglucosaminidase from streptomyces plicatus. this finding indicated that the high-mannose type oligosaccharides on glycoproteins can be changed to complex type ones by the tran ... | 2006 | 17049165 |
| crystallographic evidence for substrate-assisted catalysis in a bacterial beta-hexosaminidase. | beta-hexosaminidase, a family 20 glycosyl hydrolase, catalyzes the removal of beta-1,4-linked n-acetylhexosamine residues from oligosaccharides and their conjugates. heritable deficiency of this enzyme results in various forms of galnac-beta(1,4)-[n-acetylneuraminic acid (2,3)]-gal-beta(1,4)-glc-ceramide gangliosidosis, including tay-sachs disease. we have determined the x-ray crystal structure of a beta-hexosaminidase from streptomyces plicatus to 2.2 a resolution (protein data bank code ). bet ... | 2001 | 11124970 |
| aspartate 313 in the streptomyces plicatus hexosaminidase plays a critical role in substrate-assisted catalysis by orienting the 2-acetamido group and stabilizing the transition state. | sphex, a retaining family 20 glycosidase from streptomyces plicatus, catalyzes the hydrolysis of n-acetyl-beta-hexosaminides. accumulating evidence suggests that the hydrolytic mechanism involves substrate-assisted catalysis wherein the 2-acetamido substituent acts as a nucleophile to form an oxazolinium ion intermediate. the role of a conserved aspartate residue (d313) in the active site of sphex was investigated through kinetic and structural analyses of two variant enzymes, d313a and d313n. t ... | 2002 | 12171933 |
| elucidating the nature of the streptomyces plicatus beta-hexosaminidase-bound intermediate using ab initio molecular dynamics simulations. | by using all-atom ab initio molecular dynamics simulations, the solution pk(a) of the oxazolinium ion intermediate formed during the streptomyces plicatus beta-hexosaminidase (sphex)-catalyzed hydrolysis of beta-d-n-acetylglucosaminides is estimated as pk(a) = 7.7. the structure and protonation state of the enzyme-bound intermediate have also been investigated, using hybrid qm/mm methods. the protonation state and conformational properties of the enzyme bound intermediate are found to be sensiti ... | 2008 | 19053474 |
| biochemical and structural assessment of the 1-n-azasugar galnac-isofagomine as a potent family 20 beta-n-acetylhexosaminidase inhibitor. | azasugar inhibitors of the isofagomine class are potent competitive inhibitors of configuration-retaining beta-glycosidases. this potency results from the formation of a strong electrostatic interaction between a protonated endocyclic nitrogen at the "anomeric" center of the inhibitor and the catalytic nucleophile of the enzyme. although the majority of retaining beta-glycosidases use a mechanism involving a carboxylate residue as a nucleophile, streptomyces plicatus beta-n-acetylhexos-aminidase ... | 2001 | 11522797 |
| taxonomy and polyphasic characterization of alkaline amylase producing marine actinomycete streptomyces rochei btss 1001. | actinomycetes isolated from marine sediments along the southeast coast of bay of bengal were investigated for amylolytic activity. marine actinomycete btss 1001 producing an alkaline amylase was identified from marine sediment of diviseema coast, bay of bengal. the isolate produced alkaline amylase with maximum amylolytic activity at ph 9.5 at 50°c. the organism produced white to pale grey substrate mycelium and grayish aerial mycelium with pinkish brown pigmentation. a comprehensive study of mo ... | 2013 | 24489548 |
| endophytic actinomycetes from spontaneous plants of algerian sahara: indole-3-acetic acid production and tomato plants growth promoting activity. | twenty-seven endophytic actinomycete strains were isolated from five spontaneous plants well adapted to the poor sandy soil and arid climatic conditions of the algerian sahara. morphological and chemotaxonomical analysis indicated that twenty-two isolates belonged to the streptomyces genus and the remaining five were non-streptomyces. all endophytic strains were screened for their ability to produce indole-3-acetic acid (iaa) in vitro on a chemically defined medium. eighteen strains were able to ... | 2013 | 23579766 |
| screening of endophytic streptomycetes isolated from parthenium hysterophorus l. against nosocomial pathogens. | parthenium hysterophorus l. is an obnoxious weed of the family asteraceae recognized for its detrimental effects and significant economic losses to agriculture. in this study 42 endophytic streptomycetes strains were isolated from its roots and leaves. the isolates were identified by morphological, microscopic, biochemical and physiological characterization as members of genus streptomyces. in 16s rrna gene sequencing the selected isolates exhibited maximum similarity with streptomyces rochei (9 ... | 2013 | 23455197 |
| the effect of space flight on the production of actinomycin d by streptomyces plicatus. | the effect of space flight on production of the antibiotic actinomycin d by streptomyces plicatus wc56452 was examined onboard the us space shuttle mission sts-80. paired space flight and ground control samples were similarly prepared using identical hardware, media, and inoculum. the cultures were grown in defined and complex media under dark, anaerobic, thermally controlled (20 degrees c) conditions with samples fixed after 7 and 12 days in orbit, and viable residuals maintained through landin ... | 2002 | 12483468 |