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)

A beta-galactosidase was extracted from the internal organs of a sea squirt, Styela plicata, and purified 959-fold, with an 18% yield, by successive gel chromatography, anion-exchange chromatography, chromatofocusing, and affinity chromatography on a Con A-Sepharose column. The purified enzyme was fairly homogeneous, as judged on disc PAGE, SDS-PAGE, and gel chromatography on a Sephadex G-200 column. The molecular weight of the enzyme was estimated to be 77,000 and 75,000 by gel chromatography and SDS-PAGE, respectively, and its isoelectric point was determined to be 4.9 by the isoelectric focusing method. The enzyme was substantially stable in the pH range of 3.5 to 7.5, the optimum pH being 4.0. The enzyme was significantly inhibited by 9 mM HgCl2 and 9 mM DFP, while the inhibition by 0.9% PCMB was only 60% at 0 degrees C for 30 min. The purified beta-galactosidase apparently liberated galactose from a sea squirt antigen (H-antigen), two allergenically active glycopeptides (Gp-1 and Gp-2) derived from another sea squirt antigen (Gi-rep), asialo-ovomucoid glycopeptide, asialo-fetuin glycopeptide, GA1, CDH, and an ABEE-derivative (Gal beta 1----3ThrNAc-ABEE) of Gal beta 1----3GalNAc-ol isolated from bovine submaxillary gland mucin.
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PMID:Purification and characterization of a sea squirt beta-galactosidase. 193 20

We are attempting to develop methods for the sequencing of glycosaminoglycans from their reducing end. Here we describe a procedure for the analysis of dermatan sulphate from pig skin. The glycosaminoglycan is released from its parent proteoglycan by exhaustive proteolysis by using both endo- and exo-peptidases. The amino group of the residual serine residue is conjugated with a p-hydroxyphenyl group, which in turn is iodinated with 125I (the Bolton-Hunter reagent, BHR). The ion-exchange-purified end-labelled dermatan sulphate is then degraded partially or completely by various enzymic or chemical means to yield fragments extending from the labelled serine residue to the point of cleavage. The various products are separated by gradient PAGE, detected by autoradiography and quantified by videodensitometry. Complete digestion with chondroitin ABC lyase affords the labelled fragment delta HexA-GalNAc(-SO4)-GlcA-Gal-Gal-Xyl-Ser(-BHR). The structure was confirmed by sequential degradation from the non-reducing end by chondroitin AC lyase, HgCl2, and beta-galactosidase. Periodate oxidation cleaves most of the Xyl even without treatment with alkaline phosphatase, showing that Xyl is not substituted with phosphate. Results from partial and selective periodate oxidation indicate that most of the non-sulphated IdoA residues are located towards the non-reducing end. Partial or complete digestions with testicular hyaluronidase (in the presence of an excess of beta-glucuronidase) or chondroitin AC lyase identify the positions of GlcA residues. The results confirm that HexA next to Gal is always GlcA. Moreover, GlcA is common in the first three disaccharide repeats. Results with testicular hyaluronidase indicate that the distribution of clustered GlcA-GalNAc repeats is periodic and peaks at positions 1-3, 8-9 and around 25. Although there must be chains that contain IdoA in nearly all of the available positions, regions that have not been fully processed during biosynthesis are markedly non-random.
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PMID:A method for the sequence analysis of dermatan sulphate. 216 67

Urinary excretion of lactate dehydrogenase (LDH), glutathione-S-transferase (GST), leucine arylamidase (LAS), gamma-glutamyltransferase (GGT), beta-galactosidase (GAL), beta-N-acetyl-D-glucosaminidase (NAG), sodium, and glucose were determined in female Sprague-Dawley rats the subsequent three days after intraperitoneal treatment with single doses of 4.5 mg CdCl2 X 1H2O/kg, 20 mg Na2CrO4/kg, and 0.75 mg HgCl2/kg body weight. Although the pathological effects were localized within the same part of the nephron (i.e., the proximal tubule), there were marked differences with regard to the extent and time course of the parameters affected. Treatment with cadmium resulted essentially in a marked decline in sodium and glucose excretion. The administration of chromate led to a slightly to moderately elevated excretion of the enzyme activities measured with the cytosolic LDH as the most increased enzyme (ca. 500% of controls on Day 3 postadministration). Median glucose excretion was unaffected whereas sodium excretion was transiently reduced. The maximum of enzyme excretion after HgCl2 was essentially the same on the first day postadministration and the amount of enzyme activity in urine up to 20 times higher compared to that after chromium. Sodium excretion was below that of controls on Days 2 and 3, whereas glucose excretion was markedly elevated (up to 8000% of controls). The results indicate that it is possible to discriminate with the use of selected urinary enzymes, substrates, and electrolytes various kinds of nephrotoxic actions not only in different but also within the same part of the nephron.
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PMID:Comparative investigations on the effects of acute intraperitoneal cadmium, chromium, and mercury exposure on the kidney. 287 41

The effect of selenium (SeO2) and glutathione (GSH) on the bioaccumulation of mercury (HgCl2) and on the activities of lysosomal enzymes in four species of tropical estuarine lamellibranchs is reported. A definite correlation between mercury levels in the external medium and tissue uptake and physiological behaviour--opening and closing of shell valves, response to mechanical stimulus, mucus secretion, and incidence of bleeding--was evident. In the clams exposed to Hg (range 0.1-5.0 mg l-1), bioaccumulation was dependent on the ambient concentration of Hg. The highest bioaccumulation of Hg occurred during the initial 24 h exposure period. Further exposure of up to 7 days did not increase the body burden of Hg. Of the four bivalve species exposed to 0.1 mg Hg l-1, Perna viridis showed the highest levels of Hg (approximately 47 ppm) followed by Anadara granosa, A. rhombea (approximately 25 ppm) and Meretrix casta (approximately 9 ppm). The uptake of Hg by A. granosa was greatly reduced by GSH, whereas Se enhanced it by 50% when administered in combination with Hg. However, the presence of Hg did not influence the uptake of Se. Exposure to combined GSH and Hg resulted in almost complete inhibition of Hg uptake in all four bivalve species. Prior exposure to GSH, however, did not have the same influence on their uptake of Hg. Nevertheless, exposure of clams to GSH following initial exposure to Hg resulted in complete depuration of accumulated Hg. The activities of lysosomal enzymes--arylsulfatase, acid phosphatase, beta-galactosidase and beta-glucuronidase--varied considerably. Treatment with Hg and GSH, separately and in combination, significantly enhanced the levels of beta-galactosidase (P less than 0.05) and beta-glucuronidase (P less than 0.001) in the digestive gland after 96 h exposure. Although Se increased beta-glucuronidase activity (P less than 0.001), it had no effect on beta-galactosidase. On exposure to Hg + Se the activity of both enzymes decreased, except in P. viridis where it increased by 39%. The results show unequivocally that Se does not offer any protection against the toxic effects of mercury in marine lamellibranchs, whereas in many marine vertebrates it does. GSH, a thiol-rich tripeptide, on the other hand, completely nullifies the toxic effects of Hg, both in vivo and in vitro.
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PMID:Do selenium and glutathione inhibit the toxic effects of mercury in marine lamellibranchs? 323 22

The immature sugar cane stalks studied contained less than 7% sucrose, and showed the activities of enzymes such as invertase, alpha-galactosidase, alpha-mannosidase, beta-N-acetylglucosaminidase, beta-glucosidase, beta-xylosidase, and beta-galactosidase. The alpha-galactosidase was highly purified by ammonium sulfate fractionation, gel filtration on a Sephadex G-100 column, ionexchange chromatography on DEAE-cellulose, and CM-cellulose columns, and heat treatment (60 degrees C, 15 min) in the presence of 0.2 m D-galactose. In polyacrylamide gel electrophoresis, the purified enzyme was homogeneous, having a molecular weight of approximately 46,000. In gelfiltration, it was approximately 47,000. The activity was optimum at pH 4.5 and at 60 degrees C. The purified enzyme hydrolyzed p-nitrophenyl-alpha-D-galactopyranoside (Km, 0.83 mM; Vmax, 25.0 mumol/mg/min), raffinose (Km, 25.9 mM; Vmax, 15.4 mumol/mg/min), and stachyose (Km, 13.0 mM; Vmax 2.7 mumol/mg/min), in addition to melibiose, guar gum, and locust bean gum. The hydrolysis of p-nitrophenyl-alpha-D-galactopyranoside was markedly inhibited by HgCl2, AgNO3, p-chloromercuribenzoate (PCMB), L-ascorbic acid, melibiose, stachyose, and D-galactose. Also the purified enzyme showed a lectin activity with trypsinized erythrocytes.
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PMID:Purification and properties of alpha-galactosidase from immature stalks of Saccharum officinarum (sugar cane). 627 79