Preliminary characterization of inhibitors of Neisseria gonorrhoeae produced in vitro by Eubacterium limosum

1984 ◽  
Vol 30 (2) ◽  
pp. 251-259 ◽  
Author(s):  
A. Morin ◽  
J.-G. Bisaillon ◽  
R. Beaudet ◽  
M. Sylvestre ◽  
S. A. Saheb ◽  
...  

Among anaerobic bacteria normally found in the urogenital flora, Eubacterium limosum was found to inhibit the in vitro growth of Neisseria gonorrhoeae. The antigonococcal activity produced by E. limosum was soluble in methanol and in a chloroform–methanol mixture (30:70). The fraction soluble in chloroform–methanol (30:70) yielded eight absorbance peaks when chromatographed on Bio-Gel P-2 and the inhibitory activity was found in the first two peaks. This activity was not adsorbed on DEAE Sephacel and was eluted with distilled water in a peak considered as peak 1, on which preliminary characterization was done. The inhibitory activity of peak 1 was found to be heat and pH resistant and not susceptible to proteases, lipase, or amylases. When peak 1 was chromatographed on cellulose paper using a butanol – acetic acid (4:1) solvent system, eight different spots were detected upon spraying the paper with ninhydrin. No spot was detected with anthrone, bromothymol, nor Sudan black reagents used for the detection of carbohydrates and lipids. Based on sodium dodecyl sulfate – urea polyacrylamide gel electrophoresis and gel chromatography on Sephadex G-25, peak 1 appeared either as a diffuse band and as a single peak, respectively. The molecular weight of the inhibitory complex was estimated to be 2400. All these results suggest that the antigonococcal activity produced by E. limosum is composed of more than one low molecular weight amino compound.

1978 ◽  
Vol 175 (1) ◽  
pp. 35-46 ◽  
Author(s):  
A J MacGillivray ◽  
C Johnston ◽  
R MacFarlane ◽  
D Rickwood

After labelling of mouse liver nuclei with [gamma-32P]ATP in vitro, 10-20% of the radioactivity incorporated into the saline-soluble nuclear and HAP2 chromatin fractions was located in a low-molecular-weight component (component 10) with pI near 4.5 in urea. By using combinations of ion-exchange chromatography, preparative thin-layer isoelectric focusing and gel filtration, this component was isolated from both nuclear fractions. Recovery from the saline-soluble fraction was poor under conditions that allow endogenous phosphatases to be active. Component 10 was shown to be a phosphoprotein on the basis of enzyme-digestion experiments and the detection of phosphoserine and phosphothreonine. The 32P radioactivity did not appear to be associated with phosphorylated basic amino acids. Its molecular weight was determined by gel chromatography and electrophoresis in sodium dodecyl sulphate/polyacrylamide gels as approx. 10000, and tryptic digestion of the reduced carboxymethylated protein in urea yielded two 32P-labelled peptides. It has not been possible as yet to assign a function to component 10, though its similarity to other low-molecular-weight acidic proteins is discussed.


2003 ◽  
Vol 71 (11) ◽  
pp. 6648-6652 ◽  
Author(s):  
Steven Giles ◽  
Charles Czuprynski

ABSTRACT In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored inhibitory activity. Inhibitory activity does not require albumin domain III and appears to involve binding of a low-molecular-weight yeast-derived growth factor.


1977 ◽  
Vol 55 (9) ◽  
pp. 958-964 ◽  
Author(s):  
M. P. C. Ip ◽  
R. J. Thibert ◽  
D. E. Schmidt Jr.

Cysteine-glutamate transaminase (cysteine aminotransferase; EC 2.6.1.3) has been purified 149-fold to an apparent homogeneity giving a specific activity of 2.09 IU per milligram of protein with an overall yield of 15%. The isolation procedures involve the preliminary separation of a crude rat liver homogenate which was submitted sequentially to ammonium sulfate fractionation, TEAE-cellulose column chromatography, ultrafiltration, and isoelectrofocusing. The final product was homogenous when examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). A minimal molecular weight of 83 500 was determined by Sephadex gel chromatography. The molecular weight as estimated by polyacrylamide gel electrophoresis in the presence of SDS was 84 000. The purified enzyme exhibited a pH optimum at 8.2 with cysteine and α-ketoglutarate as substrates. The enzyme is inactivated slowly when kept frozen and is completely inactivated if left at room temperature for 1 h. The enzyme does not catalyze the transamination of α-methyl-DL-cysteine, which, when present to a final concentration of 10 mM, exhibits a 23.2% inhibition of transamination of 30 mM of cysteine. The mechanism apparently resembles that of aspartate-glutamate transaminase (EC 2.6.1.1) in which the presence of a labile hydrogen on the alpha-carbon in the substrate is one of the strict requirements.


1998 ◽  
Vol 66 (9) ◽  
pp. 4374-4381 ◽  
Author(s):  
John C. McMichael ◽  
Michael J. Fiske ◽  
Ross A. Fredenburg ◽  
Deb N. Chakravarti ◽  
Karl R. VanDerMeid ◽  
...  

ABSTRACT The UspA1 and UspA2 proteins of Moraxella catarrhalisare potential vaccine candidates for preventing disease caused by this organism. We have characterized both proteins and evaluated their vaccine potential using both in vitro and in vivo assays. Both proteins were purified from the O35E isolate by Triton X-100 extraction, followed by ion-exchange and hydroxyapatite chromatography. Analysis of the sequences of internal peptides, prepared by enzymatic and chemical cleavage of the proteins, revealed that UspA1 and UspA2 exhibited distinct structural differences but shared a common sequence including an epitope recognized by the monoclonal antibody 17C7. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), purified UspA1 exhibited a molecular weight of approximately 350,000 when unheated and a molecular weight of 100,000 after being heated for 10 min at 100°C. In contrast, purified UspA2 exhibited an apparent molecular weight of 240,000 by SDS-PAGE that did not change with the length of time of heating. Their sizes as determined by gel filtration were 1,150,000 and 830,000 for UspA1 and UspA2, respectively. Preliminary results indicate the proteins have separate functions in bacterial pathogenesis. Purified UspA1 was found to bind HEp-2 cells, and sera against UspA1, but not against UspA2, blocked binding of the O35E isolate to the HEp-2 cells. UspA1 also bound fibronectin and appears to have a role in bacterial attachment. Purified UspA2, however, did not bind fibronectin but had an affinity for vitronectin. Both proteins elicited bactericidal antibodies in mice to homologous and heterologous disease isolates. Finally, mice immunized with each of the proteins, followed by pulmonary challenge with either the homologous or a heterologous isolate, cleared the bacteria more rapidly than mock-immunized mice. These results suggest that UspA1 and UspA2 serve different virulence functions and that both are promising vaccine candidates.


1983 ◽  
Vol 59 (1) ◽  
pp. 81-103 ◽  
Author(s):  
R. Crossley ◽  
D.V. Holberton

Proteins from the axonemes and disc cytoskeleton of Giardia lamblia have been examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. In addition to tubulin and the 30 X 10(3) molecular weight disc protein, at least 18 minor components copurify with the two major proteins in Triton-insoluble structures. The most prominent minor bands have the apparent molecular weights of 110 X 10(3), 95 X 10(3) and 81 X 10(3). Protein of 30 X 10(3) molecular weight accounts for about 20% of organelle protein on gels. In continuous 25 mM-Tris-glycine buffer it migrates mostly as a close-spaced doublet of polypeptides, which are here given the name giardins. Giardia tubulin and giardin have been purified by gel filtration chromatography in the presence of sodium dodecyl sulphate. Well-separated fractions were obtained that could be further characterized. Both proteins are heterogeneous when examined by isoelectric focusing. Five tubulin chains were detected by PAGE Blue 83 dye-binding after focusing in a broad-range ampholyte gel. Giardin is slightly less acidic than tubulin. On gels it splits into four major and four minor chains with isoelectric points in the pI range from 5.8 to 6.2. The amino acid composition of the giardin fraction has been determined, and compared to Giardia tubulin and a rat brain tubulin standard. Giardins are rich in helix-forming residues, particularly leucine. They have a low content of proline and glycine; therefore they may have extensive alpha-helical regions and be rod-shaped. As integral proteins of disc microribbons, giardins in vivo associate closely with tubulin. The properties of giardins indicate that in a number of respects - molecular size, charge, stoichiometry - their structural interaction with tubulin assemblies will be different from other tubulin-accessory protein copolymers studied in vitro.


1987 ◽  
Author(s):  
J Mardiguian ◽  
M Corgier ◽  
M Jouany

Dermatan is a high molecular weight glycosaminoglycan which has been shown to enhance the inhibition of thrombin by heparin-cofactor II. The aim of this study was to establish the influence of the molecular size and the role of the carboxyl group on the in vitro activity of Dermatan Sulfate. Pig skin Dermatan Sulfate was fractionated according to molecular size by gel-chromatography on Ultrogel Ac 44. Each fraction was characterized by its sulfur content and by its mean molecular weight measured on a TSK - 4000 column in reference to standard heparin fractions. Methyl esters of the unfractionated Dermatan Sulfate with varying degree of esterification, where prepared via activation of the carboxyl groups with a carbodiimide and reaction with methanol. The results of this study show that the heparin - cofactor II mediated anti-thrombin activity of Dermatan Sulfate is increasing with the molecular weight and is abolished by esterification of the carboxyl groups. Moreover, it can be speculated that each fraction contains the same amount of high affinity fraction and that, like heparin, the potency of the high affinity component is increasing with the molecular weight.


1986 ◽  
Vol 6 (12) ◽  
pp. 4259-4267 ◽  
Author(s):  
I Sagami ◽  
S Y Tsai ◽  
H Wang ◽  
M J Tsai ◽  
B W O'Malley

Two transcription factors, COUP and S300-II, were isolated and partially purified from HeLa cell nuclear extracts. Both factors are required for the efficient transcription in vitro of the ovalbumin gene but not the simian virus 40 early genes. COUP factor binds to the chicken ovalbumin upstream promoter (COUP) sequence which lies between -70 to -90 base pairs upstream from the cap site. A series of competition experiments with a band-shifting assay was carried out to determine the relative affinity of COUP box transcription factor for various promoters. We found that a promoter DNA fragment isolated from the ovalbumin gene competes better than those isolated from the ovomucoid, Y, and alpha-genes. In contrast, the the simian virus 40 early genes, the beta-globin gene, and the adenosine deaminase gene promoters do not compete well in this assay. The molecular weight of the COUP factor was estimated by S-300 column chromatography, glycerol gradient centrifugation to be 90,000. However, two bands were observed in sodium dodecyl sulfate gel electrophoresis of cross-linked COUP factor to a 32P-labeled oligonucleotide containing the COUP sequence. The protein moieties of the major and minor bands were estimated to be 85,000 to 90,000 and 40,000 to 45,000, respectively. The S300-II factor with an apparent molecular weight of 45,000 in an S-300 column is required for function in an in vitro reconstituted transcription system. In contrast to the COUP factor, the S300-II factor does not have apparent specificity for binding to the ovalbumin gene promoter. The S300-II factor may function by interacting with RNA polymerase or other DNA-binding transcription factors.


1976 ◽  
Vol 157 (3) ◽  
pp. 745-751 ◽  
Author(s):  
P Smirnoff ◽  
S Khalef ◽  
Y Birk ◽  
S W Applebaum

1. A trypsin and chymotrypsin inhibitor was isolated by extraction of chick-pea meal at pH8.3, followed by (NH4)2SO4 precipitation and successive column chromatography on CM-cellulose and calcium phosphate (hydroxyapatite). 2. The inhibitor was pure by polyacrylamide-gel and cellulose acetate electrophoresis and by isoelectric focusing in polyacrylamide gels. 3. The inhibitor had a molecular weight of approx. 10000 as determined by ultracentrifugation and by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. A molecular weight of 8300 was resolved from its amino acid composition. 4. The inhibitor formed complexes with trypsin and chymotrypsin at molar ratios of 1:1. 5. Limited proteolysis of the inhibitor with trypsin at pH3.75 resulted in hydrolysis of a single-Lys-X-bond and in consequent loss of 85% of the trypsin inhibitory activity and 60% of the chymotrypsin inhibitory activity. Limited proteolysis of the inhibitor with chymotrypsin at pH3.75 resulted in hydrolysis of a single-Tyr-X-bond and in consequent loss of 70% of the trypsin inhibitory activity and in complete loss of the chymotrypsin inhibitory activity. 6. Cleavage of the inhibitor with CNBr followed by pepsin and consequent separation of the products on a Bio Gel P-10 column, yielded two active fragments, A and B. Fragment A inhibited trypsin but not chymotrypsin, and fragment B inhibited chymotrypsin but not trypsin. The specific trypsin inhibitory activity, on a molar ratio, of fragment A was twice that of the native inhibitor, suggesting the unmasking of another trypsin inhibitory site as a result of the cleavage. On the other hand, the specific chymotrypsin inhibitory activity of fragment B was about one-half of that of the native inhibitor, indicating the occurrence of a possible conformational change.


1981 ◽  
Vol 197 (2) ◽  
pp. 367-375 ◽  
Author(s):  
M Paulsson ◽  
D Heinegård

The cartilage matrix protein is a major non-collagenous protein in bovine cartilage. It was purified from a 5 M-guanidinium chloride extract of bovine tracheal cartilage by sequential CsCl-density-gradient centrifugation, gel chromatography in guanidinium chloride and differential precipitation. The molecular weight of the intact protein is 148 000, determined by sedimentation-equilibrium centrifugation. It was dissociated to three subunits of molecular weight 52 000 by reduction of disulphide bonds. The cartilage matrix protein was insoluble in low-salt solutions and behaved abnormally on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The content of cysteine was high, whereas the contents of aromatic amino acids were low. The carbohydrate content was 3.9% (w/w). Glycopeptides obtained after papain digestion were heterogenous on gel chromatography. Asparagine/aspartic acid was enriched in the purified glycopeptides, indicating the presence of N-glycosidic linkages to protein.


1981 ◽  
Vol 197 (2) ◽  
pp. 355-366 ◽  
Author(s):  
D Heinegård ◽  
M Paulsson ◽  
S Inerot ◽  
C Carlström

Proteoglycans were isolated from cartilage by extraction with 4M-guanidinium chloride followed by direct centrifugation in 4M-guanidinium chloride/CsCl at a low starting density, 1.34 g/ml. N-Ethylmaleimide was included in the extraction solvent as a precaution against contamination of proteoglycans with unrelated proteins mediated by disulphide exchange. A novel, discrete, low-buoyant-density proteoglycan (1.40-1.35 g/ml) was demonstrated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Its proteoglycan nature was revealed by the shift in the molecular size observed on gel electrophoresis after treatment with chondroitinase ABC. The core protein was monodisperse. The proteoglycan was further purified by gel chromatography with and without addition of hyaluronate. The proteoglycan constitutes less than 2% (by weight) of the total extracted proteoglycans and is not capable of interacting with hyaluronate. The same proteoglycan was purified in larger quantities by sequential associative and dissociative CsCl-density-gradient centrifugation, zonal rate sedimentation in a sucrose gradient and gel chromatography on Sepharose CL-4B. The pure proteoglycan had a molecular weight of 76 300 determined by sedimentation-equilibrium centrifugation and an apparent partial specific volume of 0.59 ml/g. It contained about 25% protein (of dry weight) and had remarkably high contents of leucine and cysteine as compared with other proteoglycans. The proteoglycan contained two to three large chondroitin sulphate chains and some oligosaccharides.


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