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1.
In order to identify those proteins from the plasma membrane of hamster spermatozoa that exhibit an affinity for components of the zona pellucida we have used the Western blot technique. Zonae pellucidae from postovulatory hamster oocytes were solubilized by exposure to an acidic pH and then radiolabeled using the Bolton-Hunter reagent. These 125I-zona pellucida proteins retain their immunoreactivity and migrate in three heterogeneous bands when submitted to SDS-PAGE electrophoresis. Membrane proteins from epididymal spermatozoa of mature hamsters were extracted by treatment with Nonidet P-40 and then submitted to electrophoresis (SDS-PAGE). The proteins in the gel were electrophoretically transferred to a nitrocellulose membrane and then probed with the radiolabelled zone pellucida proteins. 125I-zona pellucida proteins bind preferentially to a sperm protein with a molecular weight of 26,400 ± 1,400 daltons (n = 9). Using a similar procedure it was shown that this protein also binds 125I-Concanavalin A. The interaction between the sperm protein and the 125I-zona pellucida proteins shows species specificity as demonstrated by the fact that the hamster 125I-zona pellucida proteins do not bind to proteins extracted from ram, bull, and stallion spermatozoa. Whether this sperm protein could be implicated be implicated in the process of sperm-egg interaction is under investigation.  相似文献   

2.
A polysaccharide was isolated from the sheath of a sheathed bacterium, Sphaerotilus natans. The sheath polysaccharide (SPS) was composed of D-glucose and D-(N-acetyl)galactosamine in molar ratios of 1:4. Methylation linkage analysis revealed the presence of the residues of 4-linked glucose, 4-linked (N-acetyl)galactosamine, and 3-linked (N-acetyl)galactosamine in molar ratios of 1:3:1. The oligomer of SPS was prepared with an SPS-specific degrading enzyme from a sheath-degrading bacterium, Paenibacillus koleovorans. The oligomer was derivatized and subjected to fast atom bombardment-mass spectrometry to investigate the monosaccharide sequence of SPS. The structure of SPS was confirmed by nuclear magnetic resonance. The resulting data showed that SPS is a straight-chained basic polysaccharide constructed of a pentasaccharide repeating unit.  相似文献   

3.
Structure of a capsular polysaccharide isolated from Salmonella enteritidis   总被引:1,自引:0,他引:1  
Salmonella enteritidis is a food-borne enteric human pathogen that can form a complex protective extracellular matrix. We describe here a component of this matrix which is distinct from other known salmonella extracellular polysaccharides such as cellulose and colanic acid. We have used glycosyl composition and linkage analysis, as well as 1D and 2D NMR spectroscopy to determine the structure of this polysaccharide. We propose that the primary saccharide in the S. enteritidis capsule has a branched tetrasaccharide repeating unit having the following structure: -->3)-alpha-D-Galp-(1-->2)-[alpha-Tyvp-(1-->3)]-alpha-D-Manp-(1-->4)-alpha-L-Rhap-(1-->. This structure is partially substituted on both tyvelose and galactose with a glucose-containing side chain. It further bears considerable similarity to the O antigen from this organism, a feature found in a number of other capsules from Gram-negative bacteria. In addition, we have detected fatty acids at levels that indicate the presence of a lipid anchor.  相似文献   

4.
5.
When adult Lymnaea stagnalis specimens were treated with aqueous thiourea and BHC solutions for up to 30 days, they displayed hyperirritability after 3 +/- 2 days, manifested in climbing behaviour at the surface of the water to avoid contact with the treated medium and to take in fresh air. They remained clinging to the wall of the container for long intervals without feeding and their feeding rate as a whole was slow throughout the experiment. Owing to decalcification the shell became thin, fragile and semi-transparent. Egg mass production by the adults increased slightly, but there were fewer egg capsules (3-8/egg mass), indicating that the fertility rate was reduced. Mortality among the adult snails was high during prolonged treatment. The egg masses were swollen and were less sticky than in the controls. None of them survived. The effects of BHC treatment were more pronounced and faster than in thiourea treatment.  相似文献   

6.
7.
Structure of a cell wall polysaccharide isolated from Hypocrea gelatinosa.   总被引:1,自引:0,他引:1  
The structure of a polysaccharide isolated from the cell wall of Hypocrea gelatinosa has been investigated by means of chemical analyses and 1D and 2D NMR spectroscopy. The polysacharide has an irregular structure, idealized as follows: [carbohydrate structure in text].  相似文献   

8.
9.
An O-specific polysaccharide from the lipopolysaccharide Yersinia pseudotuberculosis 1A serovar has been isolated and characterized. This compound was shown to contain residues of paratose, 6-deoxy-D-manno-heptose, D-galactose and 2-amino-2-deoxy-D-glucose in equimolar ratios. Using methylation studies, partial acid hydrolysis and 13C NMR spectroscopy, the following structure was proposed for the repeating unit of the O-specific polysaccharide: (Formula: see text).  相似文献   

10.
A water-soluble polysaccharide isolated from Dalbergia sissoo Roxb. leaves was purified and major homogeneous fraction obtained by GPC. Complete hydrolysis of the polysaccharide followed by paper chromatography and GLC analysis indicated the presence of l-rhamnose, d-glucuronic acid, d-galactose and d-glucose in molar ratio of 1:1:2:2.33, respectively. Partial hydrolysis of the polysaccharide furnished one tri-[I], one hepta-[II] and one nona-[III] saccharides. Hydrolysis of the oligosaccharide I, II and III followed by GLC analysis furnished d-glucose and l-rhamnose (2:1); l-rhamnose, d-galactose and d-glucuronic acid (1:3:3); and l-rhamnose, d-galactose and d-glucose (1:3:5), respectively. Methylation analysis and periodate oxidation of the oligosaccharide I indicated the presence of two non reducing glucose units linked to rhamnose by 1→2 and 1→4 linkages, respectively. Oligosaccharide II is a branched molecule with a main chain consisting of 1,3-linked β-d-galactopyranosyl (2 mol), 1,3,4 linked α-l-rhamnopyranosyl (1 mol) and 1,4,6 linked β-d-galactopyranosyl unit (1 mol) and non reducing β-d-glucuronic acid at the end along with side chains of β-d-glucouronopyranosyl units (2 mol). Oligosaccharide III is also a branched molecule with a main chain consisting of 1,3,4 linked α-l-rhamnopyranosyl (1 mol), 1,2,4 linked β-d-glucopyranosyl (1 mol), 1,3 and 1,4 linked β-d-galactopyranosyl (2 and 1 mol, respectively) having β-d-glucopyranosyl as a non reducing end.  相似文献   

11.
Egg capsule material serves as a putative protection mechanism for developing snail embryos facing the perils of the marine environment. We conducted the first quantitative study of this acellular structural protein with the goals of characterizing its chemical and mechanical properties and the relationship of these properties to its biological protective function. We have found that this protein polymer exhibits long-range elasticity with an interesting recoverable yield evidenced by an order of magnitude decrease in elastic modulus (apparent failure) that begins at 3%-5% strain. This material differs significantly from other common structural proteins such as collagen and elastin in mechanical response to strain. Qualitative similarities in stress/strain behavior to keratin, another common structural protein, are more than coincidental when composition and detailed mechanical quantification are considered. This suggests the possibility of alpha-helical structure and matrix organization that might be similar in these two proteins. Indeed, the egg capsule protein may be closely related to vertebrate keratins such as intermediate filaments. We conclude that while this material's bimodal tensile properties may serve as useful protection against the impact loading egg capsules encounter in the intertidal zone, the full biological importance of these capsules is not known.  相似文献   

12.
A water-insoluble extracellular glucan (CO-1) was isolated from the precipitate formed on incubation of the culture filtrate of Cordyceps ophioglossoides at 37 degrees for 19 h. CO-1 was homogeneous as judged by h.p.l.c., electrophoresis, and ultracentrifugation, and the average molecular weight was determined by h.p.l.c. to be 632,000. The 1H- and 13C-n.m.r. and the i.r. spectra indicated that the glucosidic linkages in CO-1 were beta. From the results of methylation analysis, Smith degradation, n.m.r. studies, and enzymic hydrolysis, it was concluded that CO-1 is composed of a backbone of (1----3)-linked beta-D-glucopyranosyl residues with a beta-D-glucopyranosyl group attached to O-6 of every second D-glucopyranosyl residue of the backbone. CO-1 strongly inhibited the growth of Sarcoma 180 solid-type tumor. CO-1 polyalcohol, which was prepared by Smith degradation of CO-1, exhibited more-potent antitumor activity than CO-1. The absorption maximum of Congo Red shifted significantly in the presence of CO-1.  相似文献   

13.
In this study, a novel heteropolysaccharide was isolated from the fruiting bodies of Boletus speciosus Forst through DEAE-cellulose column and Sephadex G-200 column. The Boletus speciosus Forst polysaccharide (BSFP-1) had a molecular weight of 1.33×10(4) Da and was mainly composed of l-Man and d-Gal which ratios were 2:1. Structural features of Boletus speciosus Forst polysaccharide (BSFP-1) were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry (GC-MS), infrared (IR) spectra and nuclear magnetic resonance (NMR) spectroscopy. The results indicated that Boletus speciosus Forst polysaccharide (BSFP-1) had a backbone of (1→4)-α-l-mannopyranose residues which branches at O-6 based on the experimental results. The branches were mainly composed of one with →1)-α-d-galactopyranose residue. The antioxidant activity of BSFP-1 was evaluated with two biochemical methods, including 1,1-diphenyl-2-picrylhydrazyl (DPPH(-)) radical scavenging, scavenging activity of 2,2'-azino-bis(3-ethylbenzthiazoline-6-suphonic acid)diammonium (ABTS(+)) radical. The results indicated that BSFP-1 showed strong antioxidant.  相似文献   

14.
An expolysaccharide (EPS)-producing strain of the genus Acetobacter (named IFR 101) was isolated from a commercial vinegar acidifier. IFR 101 can be grown over the pH range 3.0–8.0 and the temperature range 12–35°C, and is ethanol-tolerant to 10% v/v. Neutral sugar analysis of the purified EPS indicates the presence of the sugars mannose, galactose and glucose. Methylation studies and NMR data suggest that the EPS may either be a complex branched polysaccharide or a mixture of simpler linear and branched structures. Aqueous preparations of IFR 101 exhibit reversible shear-thinning behaviour.  相似文献   

15.
M Moreau  R Chaby    L Szabo 《Journal of bacteriology》1984,159(2):611-617
The tetrasaccharide beta-D-glucopyranosyl-(1,3)-beta-D-glucopyranuronyl-(1, 2)-L-glycero-alpha-D-manno-heptopyranosyl-(1,5)-3-deoxy-D-manno-2- octulosonic acid was isolated after treatment of polysaccharide 1 of Bordetella pertussis endotoxin with nitrous acid. Taking into account previously identified di- and trisaccharide fragments and analytical data obtained for the intact polysaccharide 1, we present the structure of a heptasaccharide that is thought to represent the region immediately adjacent to the hydrophobic (lipid A) moiety of lipopolysaccharide 1 of the B. pertussis endotoxin. This heptasaccharide represents 50 to 60% of the complete polysaccharide structure.  相似文献   

16.
An extracellular polysaccharide containing glucose, mannose, D-manno-octulosonic acid (KDO), an unidentified component (X), and acetyl groups in the molar ratio of 1.3:3.8:1.6:1.1:2.9, was obtained from the incubated medium of a Xanthomonas species. The extracellular polysaccharide contained traces of phosphate and nitrogen but no lipid. Mild hydrolysis with 0.025M sulfuric acid released all of the KDO in the polysaccharide and a KDO-free product was obtained, which on hydrolysis with 0.05M sulfuric acid, gave mainly an oligosaccharide containing glucose, mannose, and X in molar ratio of 1:1:1. The reducing end-group of this oligosaccharide was X, and other hexose residues were linked (1 → 4). Compound X seems to be a 6-deoxyhexose that differs from fucose and rhamnose.  相似文献   

17.
The structure of the extracellular polysaccharide (EPS) produced by the Rhizobium sp. B strain isolated from atypical nodules on alfalfa has been determined using a combination of chemical and physical techniques (methylation analysis, high pH-anion exchange chromatography (HPAEC), mass spectrometry and 1-D and 2-D NMR spectroscopy). As opposed to the EPS from other strains of Rhizobium, the EPS from the sp. B strain contains D-Glc together with L-Rha and 2-deoxy-D-arabino-hexuronic acid. It is a polymer of a repeating unit having the following structure: --> 4)-beta-D-Glcp-(1 --> 4)-alpha-L-Rhap -(1 --> 3)-beta-D-Glcp-(1 --> 4)-2-deoxy-beta-D-GlcpA-(1 -->. The polysaccharide also contains 0.6 O-acetyl groups per sugar which have not been located.  相似文献   

18.
Bacterial strains growing in medium with mustard gas reaction masses (RM) as carbon sources were obtained. Growth cessation in the above medium was caused by the exhaustion of bioutilizable substrates, first of all monoethanolamine (MEA) and ethyleneglycol (EG), rather than by the accumulation of toxic metabolites in the culture liquid or in the cells. The main RM components, 1,4-perhydrothiazines (PHT), formed in the course of chemical detoxication of mustard gas, were identified and analyzed. The predominant component of PHT mixture was N-(2-hydroxyethyl)-2-methyl-1,4-perhydrothiazine hydrochloride. Concentrations of all the PHT decreased by 50% in the course of culture growth; their destruction was a result of microbial metabolism.  相似文献   

19.
20.
A neutral small molecular mass (approximately 6.5 kDa) polysaccharide comprising a pentasaccharide repeat unit was isolated from culture supernatants of Pseudomonas aeruginosa immunotype 4. The polysaccharide had a pentasaccharide repeating unit as follows (formula; see text) where Rha is rhamnose. The structure was determined using acid hydrolysis, solvolysis with anhydrous hydrogen fluoride, methylation analysis, and 1H and 13C nuclear magnetic resonance spectroscopy including nuclear Overhauser enhancement experiments. The polysaccharide bound antibody raised to the lipopolysaccharide of the seven P. aeruginosa Fisher-Devlin immunotype strains. Inhibition assays demonstrated the presence of a serologically similar polysaccharide in supernatants of these strains. Affinity-purified antibody to the polysaccharide bound to lipopolysaccharide and whole cells of the immunotype strains of P. aeruginosa in a Western immunoblot and colony blot assay, respectively. This polysaccharide seems to contain an antigenic determinant present in the core of the P. aeruginosa lipopolysaccharide or may represent another minor polysaccharide substituent on the lipopolysaccharide in addition to the O side chain.  相似文献   

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