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)

Rarobacter faecitabidus protease I (RPI) is a serine protease exhibiting lytic activity toward living yeast cells. RPI is similar to elastase in its substrate specificity and has a lectin-like affinity for mannose. The gene encoding RPI was cloned to elucidate its structure and function. And its nucleotide sequence revealed that it contains an open reading frame encoding a 525-amino acid protein. Homology comparison indicated that pre-pro-RPI consists of three domains: (1) an NH2-terminal prepro domain not found in the mature form of RPI, (2) a protease domain homologous to the trypsin family of serine proteases, and (3) a COOH-terminal domain homologous to the COOH-terminal part of Oerskovia xanthineolytica beta-1,3-glucanase and the NH2-terminal part of the ricin B chain, a lectin isolated from the part of the ricin B chain, a lectin isolated from the castor bean. The RPI gene and its mutant were subsequently expressed in Escherichia coli under its beta-galactosidase promoter to investigate the function of the COOH-terminal domain. The mutant RPI, whose COOH-terminal domain was truncated by site-directed mutagenesis, lost both its mannose-binding and yeast-lytic activity, although the protease activity was not affected. These findings suggest that the COOH-terminal domain actually participates in the mannose-binding activity and is required for yeast-lytic activity.
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PMID:Molecular structure of Rarobacter faecitabidus protease I. A yeast-lytic serine protease having mannose-binding activity. 133 45

Rat testes have been examined with a panel of lectins that bind specifically to oligosaccharide sequences having terminal or subterminal beta-galactosyl residues in O-linked glycans, or in the outer chains of complex N-linked glycans: Arachis hypogaea (peanut, AHA), Erythrina cristagalli (coral tree, ECA), Ricinus communis (castor bean, RCA120) and Abrus precatorius (jequirity bean, APA) agglutinins. Pretreatment of sections with neuraminidase, beta-galactosidase and removal of alkali-labile O-linked sequences by beta-elimination allowed the structure of these glycans to be further explored. In spermatogonia and spermatocytes there was little evidence of glycans terminating in beta-galactosyl residues, although these were present at non-reducing terminals as sialylgalactosides. The acrosome contained two subsets of O-linked glycans terminating in sialylgalactosides, while the nuclear cap showed at least two subsets of N-linked sialylgalactosyl as well as O-linked glycans. Spermatozoa exhibited minor changes in the pattern of glycosylation, although the overall pattern of beta-galactosyl expression was similar. Binding to Sertoli cells showed the presence of some unsubstituted beta-galactosyl terminals on O-linked glycans but few such N-linked residues, while terminal beta-galactosides were scanty in tubular basement membranes.
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PMID:Histochemical analysis of rat testicular glycoconjugates. 2. Beta-galactosyl residues in O- and N-linked glycans in seminiferous tubules. 163 72

The influence of amphiphilic drugs and phospholipids on the activities of beta-galactosidase and beta-glucosidase from liver lysosomal fractions of untreated rats, isolated by affinity chromatography using castor bean lectins, was studied in vitro. Chloroquine (93 microM) inhibited beta-galactosidase activity by about 30%, while O,O'-bis(diethylaminoethyl)hexestrol showed no inhibitory effect. Neutral phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelin) inhibited the enzyme slightly, while the enzyme activity was drastically reduced in the presence of acidic phospholipids (phosphatidylinositol, phosphatidylserine, bis-(monoacylglycero)phosphate). Lysosomal beta-glucosidase was strongly inhibited by chloroquine and O,O'-bis(diethylaminoethyl)-hexestrol. The neutral phospholipids showed only a moderate inhibitory effect, whereas the acidic phospholipids were stimulators. Bis(monoacylglycero)phosphate was by far the best stimulating compound.
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PMID:Amphiphilic cationic drugs and phospholipids influence the activities of beta-galactosidase and beta-glucosidase from liver lysosomal fraction of untreated rats. 298 99

The use of glucose starvation to uncouple the production of recombinant beta-galactosidase from cell growth in Escherichia coli was investigated. A lacZ operon fusion to the carbon starvation-inducible cst-1 locus was used to control beta-galactosidase synthesis. beta-Galactosidase induction was observed only under aerobic starvation conditions, and its expression continued for 6 h following the onset of glucose starvation. The cessation of beta-galactosidase expression closely correlated with the exhaustion of acetate, an overflow metabolite of glucose, from the culture medium. Our results suggest the primary role of acetate in cst-1-controlled protein expression is that of an energy source. Using this information, we metered acetate to a glucose-starved culture and produced a metabolically sluggish state, where growth was limited to a low linear rate and production of recombinant beta-galactosidase occurred continuously throughout the experiment. The cst-1 controlled beta-galactosidase synthesis was also induced at low dilution rates in a glucose-limited chemostat, suggesting possible applications to high-density cell systems such as glucose-limited recycle reactors. This work demonstrates that by using an appropriate promoter system and nutrient limitation, growth can be restrained while recombinant protein production is induced and maintained.
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PMID:Use of glucose starvation to limit growth and induce protein production in Escherichia coli. 1860 Nov 13