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 chitinase (Cht)-encoding gene from Streptomyces plicatus was previously cloned and expressed in Escherichia coli [Robbins et al., J. Biol. Chem., 263 (1988) 442-447]. We have sequenced this gene, compared its sequence with other genes encoding Cht and have explored its expression and regulation when reintroduced into Streptomyces lividans on multicopy plasmids. We have also cloned two other Streptomyces Cht-encoding genes and a beta-hexosaminidase-encoding gene in E. coli by expression in the lambda ZAP-Bluescript vector. The hexosaminidase and one of the Chts were expressed directly from the genomic library in E. coli at a high level as chimeric fusions with the beta-galactosidase alpha-complementing peptide encoded by the vector. Direct cloning and high-level expression of such chimeric proteins, which overcomes the difficulties associated with expressing Streptomyces genes in E. coli, should generally be possible wherever large numbers of transformants can be conveniently screened.
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PMID:Cloning and high-level expression of chitinase-encoding gene of Streptomyces plicatus. 153 61

A human hippocampus cDNA library in lambda ZAP II was screened by hybridization with a rat brain inositol 1,4,5-trisphosphate (InsP3) 3-kinase cDNA. Two clones (hh6 and hh3) were isolated and sequenced. The insert of clone hh6 was shown to correspond to the 3' end of the coding sequence of 50,000-Mr InsP3 3-kinase (referred to as 3-kinase-A). Sequencing of the clone hh3 insert yielded an open reading frame encoding a 472-amino acid protein with a calculated Mr of 53,451 (referred to as 3-kinase-B). The C-terminal part of 3-kinase-B (residues 187-462) was 68% identical with 3-kinase-A in amino acid sequence. The cDNA of clone hh3 was rescued as a Bluescript plasmid and expressed in Escherichia coli as a beta-galactosidase fusion product. It showed InsP3 3-kinase activity that was stimulated in the presence of Ca2+/calmodulin (more than 7-fold in a crude bacterial lysate from expressed plasmid). Regeneration of InsP3 3-kinase activity after SDS/PAGE identified a major polypeptide (Mr 60,000-65,000). The Km for InsP3 of expressed 3-kinase-B was 1.6 microM. These data provide molecular evidence for the existence of InsP3 3-kinase isoenzymes.
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PMID:Molecular cloning and expression of a new putative inositol 1,4,5-trisphosphate 3-kinase isoenzyme. 165 94

We have identified an abundant 50K phosphoprotein (pp50) in MCMV-infected 3T3-L1 cells and shown by immunofluorescence microscopy and surface-iodination experiments that pp50 is localized to the plasma membrane of the infected cell. Furthermore, the kinetics of its synthesis suggests that it belongs to the early-late class of herpesvirus proteins. Using monoclonal antibodies specific for pp50 to screen a lambda ZAP II expression library constructed from poly(A)+ mRNA of MCMV-infected cells, we have isolated a cDNA clone that synthesizes a truncated form of pp50 as a beta-galactosidase fusion protein. This allowed us to localize the partial pp50 transcript to a region between map coordinates 0.228 and 0.260 of the MCMV genome (Smith strain, Vancouver). Finally, we demonstrated that the MAb 5H10.21A recognizes an antigenic determinant that is conserved between pp50 and a 50K human cytomegalovirus (HCMV) nonstructural protein.
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PMID:Characterization of a membrane-associated phosphoprotein of murine cytomegalovirus (pp50) and its immunological cross-reactivity with a human cytomegalovirus protein. 171 Dec 56

A cDNA library for Trichinella pseudospiralis was constructed to study the expression of specific antigens. Four positive clones were identified using antibodies against the excretory/secretory (ES) products of the nematode as probe. Sequence analysis showed that they contained identical cDNA inserts of 606 bp, including a 5' non-translated region of 96 bp, a core translated segment of 408 bp and a poly(A)+ 3' terminus. It encoded a novel 136-amino-acid polypeptide. Southern blot analysis indicated that the cDNA did not cross-hybridize to the genomic digests of T. spiralis, mouse, or rat. A single copy only of its complementary sequence was found in the genome of T. pseudospiralis. Using the lambda ZAP expression system, the cDNA was induced to express a 23-kDa beta-galactosidase-fusion protein which did not cross-react with polyclonal and monoclonal antibodies against T. spiralis, heat shock proteins, or four heterologous species of nematodes. The antiserum against the fusion protein recognized a 15-kDa band from the ES products of T. pseudospiralis in immunoblotting. Immunocytolocalization demonstrated that the anti-fusion protein serum only recognized an epitope in the stichosome of T. pseudospiralis and not in T. spiralis. The protein can therefore serve as a specific antigen for the differential diagnosis of trichinellosis.
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PMID:A novel cDNA clone encoding a specific excretory/secretory antigen of larval Trichinella pseudospiralis. 1043 34