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 total of 32 strains of the family Leptospiraceae (23 strains of Leptospira interrogans, 6 strains of Leptospira biflexa, 2 strains of Leptonema and 1 strain of Leptospira parva) were examined for enzyme activities using 89 substrates (API ZYM system). More than 90% of the strains belonging to the family Leptospiraceae possessed strong activities of beta-D-galactosidase, beta-D-glucosidase and 5 esterases (C5, C6, C8, C9 and C10). More than 90% of the strains belonging to the genus Leptospira, except L. parva, had strong activities of L-lysine arylamidase and alpha-L-glutamate arylamidase. L. biflexa strains, except serovar andamana, were different from the other strains examined in that they possessed glycyl-glycine arylamidase, glycyl-phenylalanine arylamidase and L-tryptophan arylamidase. L. biflexa strains, except andamana, L. parva and Leptonema strains possessed strong activities of glycine arylamidase and leucyl-glycine arylamidase. Two strains of the genus Leptonema were different from the strains belonging to the genus Leptospira in that they possessed strong activities of beta-D-lactosidase. L. parva lacked alpha-D-galactosidase which other strains belonging to the family Leptospiraceae possessed. Dendrogram analysis revealed that strains belonging to the family Leptospiraceae were divided into 4 groups. The first group consisted of all strains belonging to L. interrogans and serovar andamana of L. biflexa; the second group consisted of the remaining 5 serovars of L. biflexa; the third group consisted of the genus Leptonema; and the fourth group consisted of only L. parva.
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PMID:Enzyme activities of the strains belonging to family Leptospiraceae detected by the API ZYM system. 289 26

Two exo-beta-galactosidases are involved in the lysosomal degradation of glycosphingolipids: GM1-beta-galactosidase (EC 3.2.1.23) and galactosylceramidase (EC 3.2.1.46). Analyses were performed with both enzymes, using lactosylceramides with varying acyl chain lengths as substrates that were inserted into unilamellar liposomes and naturally occurring sphingolipid activator proteins sap-B and sap-C, rather than detergents, to stimulate the reaction. While sap-B was a better activator for the reaction catalyzed by GM1-beta-galactosidase, sap-C preferentially stimulated lactosylceramide hydrolysis by galactosylceramidase. The enzymic hydrolysis of liposome-integrated lactosylceramides was significantly dependent on the structure of the lipophilic aglycon moiety of the lactosylceramide decreasing with increasing length of its fatty acyl chain (C2 > C4 > C6 > C8 > C10 > C18). However, in the presence of detergents the degradation rates were independent of the acyl chain length. Hydrolysis of liposomal lactosylceramide was compared with sap-B-stimulated hydrolysis of liposomal ganglioside GM1 by GM1-beta-galactosidase and sap-C-stimulated degradation of liposomal galactosylceramide by galactosylceramidase. Kinetic and dilution experiments indicated that sap-B forms water-soluble complexes with both lactosylceramide and GM1. These complexes were recognized by GM1-beta-galactosidase as optimal substrates in the same mode, as postulated for the hydrolysis of sulfatides by arylsulfatase A [Fischer, G. and Jatzkewitz, H. (1977) Biochim. Biophys. Acta 481, 561-572]. GM1-beta-galactosidase was more active on these complexes than on glycolipids (GM1 and lactosylceramides) still residing in liposomal membranes. On the other hand, dilution experiments indicated that degradation of galactosylceramide and lactosylceramide by galactosylceramidase proceeds almost exclusively on liposomal surfaces: both activators, sap-C and sap-B, stimulated the hydrolysis of lactosylceramide analogues with long acyl chains more than the hydrolysis of lactosylceramides with short acyl chains.
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PMID:Hydrolysis of lactosylceramide by human galactosylceramidase and GM1-beta-galactosidase in a detergent-free system and its stimulation by sphingolipid activator proteins, sap-B and sap-C. Activator proteins stimulate lactosylceramide hydrolysis. 820 Mar 56

A phage-inducible middle promoter (P15A10) from the lytic, lactococcal bacteriophage phi 31, a member of the P335 species, is located in an 888-base pair fragment near the right cohesive end. Sequence analysis revealed extensive homology (> 95%) to the right cohesive ends of two temperate phages of the P335 species, phi r1t and phi LC3. Sequencing upstream and downstream of P15A10 showed that the high degree of homology between phi 31 and phi r1t continued beyond the phage promoter. With the exception of one extra open reading frame in phi 31, the sequences were highly homologous (95 to 98%) between nucleotides 13,448 and 16,320 of the published phi r1t sequence. By use of a beta-galactosidase (beta-Gal) gene under the control of a smaller, more tightly regulated region within the P15A10 promoter, P566-888, it was established that mitomycin C induction of a lactococcal strain harboring the prophage phi r1t induced the P566-888 promoter, as determined from an increase in beta-Gal activity. Hybridization of nine other lactococcal strains with 32P-labeled P566-888 showed that the Lactococcus lactis strains C10, ML8, and NCK203 harbored sequences homologous to that of the phage-inducible promoter. Mitomycin C induced the resident prophages in all these strains and concurrently induced the P566-888 promoter, as determined from an increase in beta-Gal activity. DNA restriction analysis revealed that the prophages in C10, ML8, and NCK203 had identical restriction patterns which were different from that of phi r1t. In addition, DNA sequencing showed that the promoter elements in the three phages were identical to each other and to P566-888 from the lytic phage phi 31. These results point to a conserved mechanism in the regulation of gene expression between the lytic phage phi 31 and at least two temperate bacteriophages and provide further evidence for a link in the evolution of certain temperate phages and lytic phages.
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PMID:Common elements regulating gene expression in temperate and lytic bacteriophages of Lactococcus species. 950 53

A novel system that leaks beta-galactosidase (beta-gal) without a requirement for secretion or export signals was developed in Lactococcus lactis by controlled expression of integrated phage holin and lysin cassettes. The late promoter of the lytic lactococcal bacteriophage phi31 is an 888-bp fragment (P(15A10)) encoding the transcriptional activator. When a high-copy-number P(15A10)::lacZ.st fusion was introduced into L. lactis strains C10, ML8, NCK203, and R1/r1t, high levels of the resultant beta-gal activity were detected in the supernatant (approximately 85% of the total beta-gal activity for C10, ML8, and NCK203 and 45% for R1/r1t). Studies showed that the phenotype resulted from expression of Tac31A from the P(15A10) fragment, which activated a homologous late promoter in prophages harbored by the lactococcal strains. Despite the high levels of beta-gal obtained in the supernatant, the growth of the strains was not significantly affected, nor was there any evidence of severe membrane damage as determined by using propidium iodide or transmission electron microscopy. Integration of the holin-lysin cassette of phage r1t, under the control of the phage phi31 late promoter, into the host genome of MG1363 yielded a similar "leaky" phenotype, indicating that holin and lysin might play a critical role in the release of beta-gal into the medium. In addition to beta-gal, tetanus toxin fragment C was successfully delivered into the growth medium by this system. Interestingly, the X-prolyl dipeptidyl aminopeptidase PepXP (a dimer with a molecular mass of 176 kDa) was not delivered at significant levels outside the cell. These findings point toward the development of bacterial strains able to efficiently release relevant proteins and enzymes outside the cell in the absence of known secretion and export signals.
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PMID:Leaky Lactococcus cultures that externalize enzymes and antigens independently of culture lysis and secretion and export pathways. 1113 53

A Gram-negative, strictly aerobic bacterium, designated strain byr23-80T, was isolated from lysimeter soil by using a high-throughput cultivation technique. Cells of strain byr23-80T were found to be short rods that multiplied by binary fission and were motile by means of a single polar flagellum. Occasionally, two to three polar or lateral flagella were observed. The optimum growth temperature was 15 degrees C and the pH optimum was 7.0-7.5. The predominant cellular fatty acids were C16 : 1omega7c (54.7 %) and C16 : 0 (21.4 %). In addition, the diagnostic fatty acids C10 : 0 3-OH and C12 : 0 2-OH were detected. Q-8 was the predominant respiratory quinone. The isolate was physiologically very versatile, using a wide range of sugars, organic acids and amino acids as single carbon and energy sources for growth. The G+C content of the genomic DNA was 65.3 mol%. Phylogenetic analyses supported the assignment of strain byr23-80T to the genus Massilia within the family Oxalobacteraceae of the class Betaproteobacteria. Within the genus, strain byr23-80T was most closely related to Massilia aurea DSM 18055T, with a 16S rRNA gene sequence similarity of 98.3 %. However, DNA-DNA hybridization revealed a pairwise similarity for the genomic DNA of only 20.1 % between strain byr23-80T and strain DSM 18055T. The novel isolate could be distinguished from the existing species Massilia timonae, Massilia dura, Massilia albidiflava, Massilia plicata, Massilia lutea and M. aurea by its significantly lower temperature optimum for growth and by the absence of gelatinase, alpha-galactosidase and beta-galactosidase activities. On the basis of these characteristics, strain byr23-80T constitutes a novel species of the genus Massilia, for which the name Massilia brevitalea sp. nov. is proposed. The type strain is byr23-80T (=DSM 18925T=ATCC BAA-1465T).
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PMID:Massilia brevitalea sp. nov., a novel betaproteobacterium isolated from lysimeter soil. 1845 Jul 22

The synthesis and properties of gemini surfactants of the type (R(1)(CO)-Lys(H)-NH)2(CH2)n are reported. For a spacer length of n = 6, the hydrophobic acyl tail was varied in length (R(1) = C8, C10, C12, C14, C16, and C18) and, for R(1) = C18, the degree of unsaturation. For R(1)(CO) = oleoyl (C18:1 Z) the spacer length (n = 2-8) and the stereochemistry of the lysine building block were varied; a 'half-gemini' derivative with a single oleoyl tail and head group was also prepared. The potential of the gemini surfactants to transfer polynucleotides across a cell membrane was investigated by transfection of HeLa cells with beta-galactosidase, both in the presence and absence of the helper lipid DOPE. Oleoyl was found to be by far the best hydrophobic tail for this biological activity, whereas the effect of the lysine stereochemistry was less pronounced. The effect of an optimum spacer length (n = 6) was observed only in the absence of helper lipid. The most active surfactant, i.e. the one with oleoyl chains and n = 6, formed liposomes with sizes in the range of 60-350 nm, and its lipoplex underwent a transition from a lamellar to a hexagonal morphology upon lowering the pH from 7 to 3.
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PMID:Structure-delivery relationships of lysine-based gemini surfactants and their lipoplexes. 2496 40