Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Essential to the pathogenesis of leishmaniasis is the ability of Leishmania spp. to attach to mononuclear phagocyte surfaces before entering this host cell which they parasitize. We have investigated the attachment phase of infection in vitro by quantitating the percent of human peripheral blood monocytes pretreated with cytochalasin (to prevent parasite entry) to which tissue-derived L. tropica amastigotes will attach during coincubation at 37 degrees C in serum-free medium. We determined that pretreatment of parasites with trypsin, chymotrypsin, Pronase, and neuraminidase reduced attachment. In contrast, parasites treated with beta-galactosidase had an enhanced ability to attach to host cells. Treatment of monocytes with chymotrypsin and Pronase, but not with trypsin or neuraminidase, reduced attachment of untreated amastigotes. We propose that in vitro amastigote attachment under serum-free conditions depends on the interaction of protein determinants on the surface of both parasite and host cell.
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PMID:In vitro parasite-monocyte interactions in human leishmaniasis: effect of enzyme treatments on attachment. 641 14

The cyanogen bromide fragment CB67-129 of human prethrombin 1, corresponding to residues 54-116 of the thrombin B chain, is a potent chemotaxin for human peripheral blood monocytes and the murine macrophage like cell line, J774. Both of these cell types have been shown to respond chemotactically to alpha-thrombin and iPr2P-alpha-thrombin. Effective concentrations for stimulating directed cell movement with the fragment vary from 10(-11) to 10(-7) M. Moreover, CB67-129 and its parent protein compete for the same chemotactic receptor site. Fragment CB67-129, representing residues 54-116 of the human thrombin B chain sequence, contains a nine-residue insertion ("loop B") that is absent in homologous sequences derived from the closely related proteases chymotrypsin and trypsin. Unlike iPr2P-alpha-thrombin, iPr2P derivatives of these latter enzymes possess little or no chemotactic activity, suggesting a relationship between the insertion sequence and thrombin chemotactic activity. The loop B sequence is unique insofar as it contains all of the carbohydrate moieties known to reside in alpha-thrombin. However, chemotactic activity is only minimally reduced subsequent to hydrolysis by both neuraminidase and beta-galactosidase, indicating that receptor recognition and stimulated cell movement are mainly a function of structure of the cyanogen bromide derived fragment rather than of asparagine-linked carbohydrates.
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PMID:Localization of a chemotactic domain in human thrombin. 670 77

Enzymatic characterization of 48 Aeromonas hydrophila complex isolates from various sources was determined with the API ZYM system (Analytab Products, Plainview, N.Y.). All isolates lacked valine and cystine aminopeptidases, chymotrypsin, alpha-mannosidase, alpha-fucosidase, alpha-galactosidase, and beta-glucuronidase but possessed caprylate esterase-lipase, leucine aminopeptidase, acid phosphatase, phosphoamidase, and N-acetyl-beta-glucosidase. Variability was found in the presence of alkaline phosphatase, butyrate esterase, myristate lipase, trypsin, beta-galactosidase, alpha-glucosidase, and beta-glucosidase. No significant differences were evident among the enzymatic profiles of isolates from various sources.
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PMID:Enzymatic characterization of Aeromonas hydrophila complex by the API ZYM system. 681 46

A boiled extract acidified to pH 5.5 from the blood plasma of partially hepatectomized rats was treated with neuraminidase and injected i.p. into untreated rats. The DNA-synthesis of the liver cells showed a four-fold increase in comparison with controls. Extracts from the plasma of partially hepatectomized rats without neuraminidase treatment showed no increase in DNA-synthesis. Injections of boiled acid extracts from plasma of normal rats, however, showed no comparable differences before and after neuraminidase treatment. The activity of neuraminidase treated boiled, plasma extract is lost after treatment both with trypsin-chymotrypsin and with beta-galactosidase. Gel chrmoatography of the factor gave a molecular weight of about 38,000 D. The specific activity of the active extract after chromatography was raised by a factor of 300. According to affinity chromatography the factor was shown to be a glycoprotein containing N-Ac-glucosamine. The factor is inert with respect to the proliferation of spleen and kidney, i.e. it is organ specific. According to these results a regulatory system of hepatopoiesis is proposed.
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PMID:Evidence for and characterization of a liver cell proliferation factor from blood plasma of partially hepatectomized rats. 737 73

We describe a new approach for the production of peptides using a combination of recombinant DNA technology, chemical synthesis, and proteinase-catalyzed processing. An artificial substance P-precursor is produced as a beta-galactosidase (1-459) fusion protein containing nine copies of the decapeptide sequence Arg-Leu-Arg-Arg-Pro-Lys-Pro-Gln-Gln-Phe. The fusion protein accumulates in E. coli as insoluble inclusion bodies which are easily isolated and purified. The decapeptide blocks are selectively cleaved from the insoluble fusion protein by alpha-chymotrypsin. Alternatively, a dodecapeptide ester is produced when a dipeptide ester is included in the chymotrypsin reaction mixture. This peptide ester is converted converted to substance P by papain-catalyzed acyl transfer and subsequent tryptic cleavage. These results demonstrate that peptides can be readily produced by a combination of recombinant DNA technology and proteinase-catalyzed conversion. The approach allows incorporation of groups other than natural amino acids into oligo- and polypeptides.
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PMID:Peptide production by a combination of gene expression, chemical synthesis, and protease-catalyzed conversion. 768 60

Saposin B is involved in the hydrolysis of sulfatides, GM1 ganglioside, globotriaosylceramide, and several other sphingolipids and glycerolipids by lysosomal hydrolases. Saposin B is one of four small glycoproteins (saposins) derived from prosaposin. The carbohydrate chain of saposin B was removed and deglycosylated saposin B was characterized and compared with native saposin B. Deglycosylated saposin B stimulated the enzymatic hydrolysis of ganglioside GM1 by acid beta-galactosidase and sulfatide by arylsulfatase A to the same extent as native saposin B. In addition deglycosylated saposin B bound sulfatide and GM1 ganglioside identical to native saposin B. The stability of native saposin B to proteolytic digestion was unchanged by deglycosylation. Neither native saposin B nor deglycosylated saposin B were hydrolyzed by trypsin, endoproteinase Glu-C (V-8), chymotrypsin, or a mixture of acid proteases isolated from human testis. Unlike its effect on metabolic stability, the carbohydrate chain appears to affect folding of saposin B. When native and deglycosylated saposin B were reduced under denaturing conditions and refolded under identical conditions examination of the refolded products indicated that each protein was refolded in a qualitatively different way. A human mutation in saposin B-deficient metachromatic leukodystrophy, in which its glycosylation site is eliminated, has been reported. Our observations suggest that instability of the mutated saposin B is not due to the absence of a protective effect of the carbohydrate chain on proteolysis, but is likely due to aberrant folding resulting from the absence of a carbohydrate chain.
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PMID:The effect of carbohydrate removal on stability and activity of saposin B. 809 82

An Escherichia coli tyrosine auxotroph (MR1) with an inducible lacZ was generated by mutagenesis. Of several tyrosine derivatives tested, only m-fluorotyrosine supported the growth of this mutant and allowed synthesis of active beta-galactosidase. The pH profiles of the beta-galactosidase that was obtained when this mutant was grown on m-fluorotyrosine (81.5% of the tyrosine was replaced by m-fluorotyrosine) indicated that a tyrosine may be acting as a general acid-base catalyst and that it (or another tyrosine with the same pKa) may be involved in substrate binding. Inactivation of normal beta-galactosidase by treatment with lactoperoxidase in the presence of I- did not affect affinity-column binding, but incubation of this iodinated beta-galactosidase with chymotrypsin caused a rapid degradation of a portion of the treated enzyme equal to the portion of the activity that was lost. A study with 125I- showed that the rapid degradation was mainly confined to iodinated molecules of enzyme. These studies indicate that iodination of beta-galactosidase does not affect binding ability, but causes the enzyme to lose catalytic activity and become susceptible to chymotryptic action. Chloroperoxidase also caused rapid inactivation of normal beta-galactosidase in the presence of Br- or I-, but there was a lag followed by a slow inactivation in the presence of Cl-.
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PMID:The properties of beta-galactosidases (Escherichia coli) with halogenated tyrosines. 839 70

An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for alpha-galactosidase, alpha-mannosidase, beta-glucosidase, beta-glucuronidase, cystine aminopeptidase, N-acetyl-beta-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; alpha-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; beta-galactosidase, 2 isolates; and alpha-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P < or = 0.001) than by habitation with calves from other farms while in the feedyard.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of Pasteurella haemolytica A1 isolates from market-stressed feeder calves by use of enzyme and antimicrobial susceptibility profiles. 842 78

The enzymatic activity of 70 feline and canine Microsporum canis isolates was determined by the Api-Zym test. The liquid phase of cultures, inoculated into Tryptic Soy Broth, was used to examine 19 enzymes. Considerable differences were observed among the extracellular enzymatic patterns. All the isolates produced alkaline phosphatase and beta-glucosidase, while lipase (C14), trypsin, chymotrypsin, beta-glucuronidase, and alpha-fucosidase activity was never revealed. Esterase (C4) activity was present in 57 samples (81%), esterase lipase (C8) in 31 (44%), leucine arylamidase in 35 (50%), valine arylamidase and cystine arylamidase in 7 (10%), acid phosphatase in 64 (91%), naphthol-AS-BI-phosphohydrolase in 60 (86%), alpha-galactosidase in 5 (7%), beta-galactosidase in 6 (8%), alpha-glucosidase in 25 (36%), N-acetyl-beta-glucosaminidase in 41 (58%), and alpha-mannosidase in 51 (73%). The beta-galactosidase activity of M. canis has not been reported previously. Remarkable variations of intensity for each enzymatic activity were also detected. It is believed that these results could provide basic data for further investigations on the pathogenic role of enzymes secreted by M. canis.
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PMID:Extracellular enzymatic activity of Microsporum canis isolates. 868 26

In this study, using the API-ZYM system, we have reported the enzyme profile of 42 soil strains and 2 clinical strains of Nocardia asteroides isolated locally. Of the 19 enzymes tested, only 7 were demonstrable in over 90% of the soil isolates. These included alkaline phosphatase, esterase lipase, leucine arylamidase, acid phosphatase, phosphohydrolase, alpha-glucosidase and beta-glucosidase. In addition, beta-galactosidase activity was demonstrated in all the strains by the O-nitrophenyl-beta-D-galactopyranoside (ONPG) test. The enzymes which were not demonstrable in > 95% of the strains included valine arylamidase, cystine arylamidase, trypsin, chymotrypsin, alpha-galactosidase, beta-glucoronidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase and alpha-fucosidase. With the exception of valine arylamidase, which was lacking in all but one isolate, the enzyme profiles of the soil isolates were comparable with the clinical isolates of N. asteroides reported in previous studies. The reasons for this difference in the two sets of isolates is not clear. The study reinforces the view that specific differences in the enzymatic profiles of Nocardia species could be used for their rapid identification. However, more extensive studies are needed to establish the reproducibility of this method. To the best of our knowledge, this is the first study of the enzymatic profile of soil isolates of N. asteroides originating from a single geographic region.
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PMID:A study of the enzymatic profile of soil isolates of Nocardia asteroides. 1035 11


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