Gene/Protein Disease Symptom Drug Enzyme Compound
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It has been described that pituitary growth hormone shows molecular and functional heterogeneity. In birds, size and charge variants of chicken growth hormone (cGH) have been shown in the chicken pituitary gland and in purified preparations of the hormone. Here we demonstrate the existence of cGH molecular isoforms in chicken serum, thus suggesting that they are secreted from the gland. The isolation of total cGH present in sera was performed by immunoaffinity chromatography employing a specific monoclonal antibody against cGH. Different analytical electrophoretic methods (SDS-polyacrylamide gel electrophoresis, isoelectric focusing, bidimensional polyacrylamide gel electrophoresis) followed by Western blot and immunostaining were employed to characterize the serum cGH isoforms, and compared to those present in a fresh pituitary extract. Several identical immunoreactive bands comigrated in both serum and the gland extract in the different systems (SDS-PAGE, MW 16, 22, 26, 29, 52, 62, 66 kDa; IEF, pIs 8.1, 7.5, 7.1, 6.8, 6.2), thus revealing a high correspondence of molecular isoforms of the hormone in the two tissues. Additionally, a glycosylated variant of chicken growth hormone (G-cGH) was also revealed in the serum after concanavalin A-Sepharose chromatography.
Gen Comp Endocrinol 1992 Nov
PMID:Identification of growth hormone molecular variants in chicken serum. 147 45

A Leuconostoc mesenteroides ssp. mesenteroides was isolated from goat's milk on the basis of its ability to inhibit the growth of Listeria monocytogenes. The antimicrobial effect was due to the presence in the culture medium of a compound, named mesentericin Y105, excreted by the Leuconostoc mesenteroides Y105. The compound displayed known features of bacteriocins from lactic acid bacteria. It appeared as a proteinaceous molecule exhibiting a narrow inhibitory spectrum limited to genus Listeria. The apparent relative molecular mass, as indicated by activity detection after SDS-PAGE, was 2.5-3.0 kDa. The bacteriocin was purified to homogeneity by a simple three-step procedure: a crude supernatant obtained from an early-stationary-phase culture in a defined medium was subjected to affinity chromatography on a blue agarose column, followed by ultrafiltration through a 5 kDa cut-off membrane, and finally by reverse-phase HPLC on a C4 column. Microsequencing of the pure bacteriocin and of tryptic fragments showed that mesentericin Y105 is a 36 amino acid polypeptide whose primary structure is close to that of leucocin A-UAL 187, which contains an extra residue at the C-terminus and displays only two differences in the overlapping sequence. However, unlike leucocin A-UAL 187, mesentericin Y105 displayed a bactericidal mode of action.
J Gen Microbiol 1992 Dec
PMID:Characterization and purification of mesentericin Y105, an anti-Listeria bacteriocin from Leuconostoc mesenteroides. 148 37

A DNA fragment containing the gene for a cell wall hydrolase of Bacillus licheniformis was cloned into Escherichia coli. Sequencing of the fragment showed the presence of an open reading frame which encodes a polypeptide of 253 amino acids with a molecular mass of 27,513. The gene was designated as cwlM, for cell wall lysis. The deduced amino acid sequence indicated that there is a repeated sequence consisting of 33 amino acid residues in the C-terminal region. Deletion of the C-terminal region did not lead to any loss of cell wall lytic activity. The gene product purified from E. coli cells harboring a cwlM-bearing plasmid exhibited a M(r) value of 29 kDa on SDS-polyacrylamide gels, and characterization of the specific substrate bond cleaved by CWLM indicated that the enzyme is an N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28). The enzyme hydrolyzed the cell wall of Micrococcus luteus more efficiently than those of B. licheniformis and B. subtilis, but the truncated CWLM (lacking the C-terminal region) had lost this preference. CWLM prepared from B. subtilis cells harboring a plasmid containing cwlM had a similar M(r) value to that from E. coli. Amino acid sequence homologies between CWLM and other amidases, and their protein structures are discussed.
Mol Gen Genet 1992 Jul
PMID:Genetic structure, isolation and characterization of a Bacillus licheniformis cell wall hydrolase. 149 75

The surface antigens of Helicobacter pylori conferring erythrocyte-binding activity were obtained by adsorption onto formaldehyde-treated dog and goat erythrocytes from supernatant fractions of sonicated bacteria and elution using a high concentration of NaCl. The desorbed material was analysed by SDS-PAGE and immunoblotting with anti-whole-cell serum to agar-grown bacteria which had been absorbed with broth-grown, non-haemagglutinating cells (haemagglutination-associated antiserum). Two polypeptides with molecular masses of 25 and 59 kDa were revealed as erythrocyte-binding antigens. Strains which agglutinated both dog and goat erythrocytes possessed both these erythrocyte-binding antigens, whereas an antigenically cross-reactive 24 kDa polypeptide was present in a strain which only agglutinated goat erythrocytes. Haemagglutinin material was extracted from H. pylori using n-octylglucopyranoside and purified by Sepharose chromatography and sucrose density gradient ultracentrifugation. The purified extract directly agglutinated erythrocytes in a neuraminyl-lactose-sensitive and neuraminidase-sensitive manner. The 59 kDa polypeptide was not present in the purified haemagglutinin preparation. The haemagglutination-associated antiserum reacted strongly with the 25 kDa polypeptide band which was the most prominent polypeptide band on analysis of the purified haemagglutinin preparation by SDS-PAGE and silver staining. Thus, H. pylori possesses at least two adhesins, one of which recognises a N-acetylneuraminic acid (alpha 2-3) moiety of receptors, the other being of unknown receptor specificity. Differences in the antigenicity and molecular masses of these adhesins in individual strains may underlie differences in receptor-binding specificities and haemagglutination profiles.
J Gen Microbiol 1992 Jul
PMID:Identification of erythrocyte-binding antigens in Helicobacter pylori. 151 79

A beta-lactamase was purified 430-fold from the culture supernatant of Acinetobacter calcoaceticus by ion exchange chromatography on CM-Sephadex and affinity chromatography on phenylboronic-acid-agarose. The purified enzyme was homogeneous as judged by SDS-PAGE, and was characterized with respect to molecular mass (38 and 41 kDa by gel filtration on Sephadex G-75 and SDS-PAGE, respectively), pH optimum (pH 7.0), temperature optimum (45 degrees C) and isoelectric point (9.3). The beta-lactamase showed mainly cephalosporinase activity. It was inhibited by cloxacillin, carbenicillin, penicillanic acid sulphone (sulbactam) and aztreonam. It was not inhibited by clavulanic acid up to a concentration of 0.25 mM. Neither EDTA nor p-chlormercuribenzoate, up to concentrations of 1 or 100 mM, respectively, affected activity. According to these characteristics, it is a typical CEP-N cephalosporinase.
J Gen Microbiol 1992 Jun
PMID:Purification and characterization of an extracellular beta-lactamase produced by Acinetobacter calcoaceticus. 152 94

Determination of the cell-surface hydrophobicity of group B streptococci by hydrophobic interaction chromatography on phenyl-Sepharose revealed that human and bovine group B streptococcal isolates with protein surface antigens, either alone or in combination with polysaccharide antigens, were mainly hydrophobic, whereas those with polysaccharide antigens alone were mainly hydrophilic. Removal of capsular neuraminic acid enhanced, and pronase treatment reduced, surface hydrophobicity. The hydrophobic surface proteins, solubilized by mutanolysin treatment of the bacteria and isolated by hydrophobic interaction chromatography, appeared in SDS-PAGE as numerous protein bands. Staphylococcal carrier cells loaded with antibodies produced against hydrophobic surface proteins agglutinated specifically with hydrophobic group B streptococci. No agglutination reaction was observed with hydrophilic cultures. Hydrophobic group B streptococci adhered to buccal epithelial cells in significantly higher numbers than did hydrophilic cultures. The adherence of group B streptococci to epithelial cells was inhibited in the presence of isolated hydrophobic proteins and in the presence of specific antibodies produced against hydrophobic proteins. The results of this study demonstrate a close relation between the occurrence of type-specific antigens, surface hydrophobicity and the adherence of group B streptococci to epithelial cells.
J Gen Microbiol 1992 Jun
PMID:Role of hydrophobic surface proteins in mediating adherence of group B streptococci to epithelial cells. 152 95

In addition to GvpA, the main structural protein, an SDS-soluble protein has been found in gas vesicles isolated from six different genera of cyanobacteria. N-terminal sequence analysis of the first 30 to 60 residues of the gel-purified proteins showed that they were homologous to GvpC, a protein that strengthens the gas vesicle in Anabaena flos-aquae. The proteins from some of the organisms showed rather low homology, however, and this may explain why the genes that encode them have not been found by Southern hybridization studies. The gas vesicles of another cyanobacterium, Dactylococcopsis salina, contained two SDS-soluble proteins (M(r) 17,000 and 35,000) that were identical in sequence for the first 24 residues but not thereafter; these two proteins showed no clear homology to GvpC. The sequence of GvpA, the main structural gas vesicle protein, was very similar in each of the organisms investigated. GvpA from the purple bacterium Amoebobacter pendens was different for the first 8 residues but 51 of the next 56 residues were identical to those of the cyanobacterial GvpA. Analysis of the GvpA and GvpC sequences provides support for the idea that the low diversity of GvpA reflects a high degree of conservation rather than a recent origin followed by lateral gene transfer between different bacteria.
J Gen Microbiol 1992 Jun
PMID:The homologies of gas vesicle proteins. 152 96

The phototrophic bacterium Rhodobacter sphaeroides strain Si4 induced ribitol dehydrogenase (EC 1.1.1.56) when grown on ribitol- or xylitol-containing medium. This ribitol dehydrogenase was purified to apparent homogeneity by ammonium sulphate precipitation, affinity chromatography on Procion red, and chromatography on Q-Sepharose. For the native enzyme an isoelectric point of pH 6.1 and an apparent M(r) of 50,000 was determined. SDS-PAGE yielded a single peptide band of M(r) 25,000 suggesting a dimeric enzyme structure. The ribitol dehydrogenase was specific for NAD+ but unspecific as to its polyol substrate. In order of decreasing activity ribitol, xylitol, erythritol, D-glucitol and D-arabitol were oxidized. The pH optimum of substrate oxidation was 10, and that of substrate reduction was 6.5. The equilibrium constant of the interconversion of ribitol to D-ribulose was determined to be 0.33 nM at pH 7.0 and 25 degrees C. The Km-values determined for ribitol, ribulose, xylitol and NAD+ (in the presence of ribitol) were 6.3, 12.5, 77 and 0.077 mM, respectively. Because of the favourable Km for ribitol, a method for quantitative ribitol determination was elaborated.
J Gen Microbiol 1992 Jun
PMID:Pentitol metabolism of Rhodobacter sphaeroides Si4: purification and characterization of a ribitol dehydrogenase. 152 98

Piromyces sp. strain E2, an anaerobic fungus isolated from an Indian elephant (hindgut fermenter) was tested for its ability to ferment a range of substrates. The fungus was able to use bagasse, cellobiose, cellulose, fructose, glucose, lactose, mannose, starch, wheat bran, wheat straw, xylan and xylose. Formate and acetate were the main fermentation products after growth on these substrates. The amount of carbon found in the fermentation products of cultures, in which substrate digestion was complete averaged 88.5 mM, or 59% of the carbon offered as substrate. No growth was observed on other substrates tested. Lactose, starch, cellobiose and filter paper cellulose were good inducers of cellulolytic and xylanolytic enzymes. Cellulolytic and xylanolytic enzymes were produced constitutively by Piromyces strain E2, although enzyme activities were generally lower after growth on glucose and other soluble sugars. Complex substrates (bagasse, wheat bran, and wheat straw) were good inducers for xylanolytic enzymes but not for cellulolytic enzymes. The extracellular protein banding pattern after SDS-PAGE was therefore only slightly affected by the growth substrate. Identical beta-glucosidase and endoglucanase activity patterns were found after growth on different substrates. This indicated that differences in enzyme activities were not the result of secretion of different sets of isoenzymes although it remains possible that the relative amount of each isoenzyme produced is influenced by the growth substrate.
J Gen Microbiol 1992 Aug
PMID:Production of cellulolytic and xylanolytic enzymes during growth of the anaerobic fungus Piromyces sp. on different substrates. 152 5

Mutants resistant to 3-aminobenzamide, a known inhibitor of ADP-ribosyltransferase, were obtained from Streptomyces griseus IFO 13189, a streptomycin-producing strain. One (strain no. 4), which had significantly reduced ADP-ribosyltransferase activity, was analysed in detail. Mutant 4 displayed a conditional phenotype with respect to cultivation temperature. At 30 degrees C, it exhibited severely reduced ability to produce aerial mycelium (on solid medium) and submerged spores and streptomycin (in liquid culture), but this ability was fully restored at 25 degrees C. The mutant produced A-factor normally, regardless of cultivation temperature, and exhibited normal ability to accumulate ppGpp intracellularly. SDS-PAGE analyses of cellular proteins labelled by [32P]NAD revealed that an ADP-ribosylated protein with a molecular size of 44 kDa, which appeared in sporulating cultures of the parent strain, was missing from the mutant grown at the non-permissive temperature (30 degrees C). Genetic analysis showed that the aba mutation conferring resistance to 3-aminobenzamide was tightly linked to the altered phenotype. Failure to ADP-ribosylate certain cellular protein(s), presumably due to the aba mutation, may be responsible for impaired differentiation in this mutant.
J Gen Microbiol 1992 Aug
PMID:The possible role of ADP-ribosylation in sporulation and streptomycin production by Streptomyces griseus. 152 13


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