Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hepatitis B virus, although containing a DNA genome, replicates by reverse transcription of an RNA pregenome. The viral Pol gene encodes the reverse transcriptase which catalyzes viral DNA synthesis. To study the interaction of this protein with HBV RNA, the entire Pol gene product was expressed except its eight amino-terminal codons in Escherichia coli as fusion protein with beta-galactosidase. In the absence of competing nucleic acids full-length expression products were able to nonspecifically bind in vitro synthesized HBV RNAs of different polarity and length. However, if competed with an excess of unspecific RNA, only those HBV RNAs were bound which contained besides the direct repeats 1 and 2 nucleotide sequences downstream of direct repeat 1. The corresponding binding site was found to be located within the adjacent 134 nucleotides downstream of DR1. We conclude from our data that this region which is in part homologous to the U5 region of retroviral genomes may be important for the binding of the HBV Pol gene product to the viral pregenome.
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PMID:Identification of a binding site in the hepatitis B virus RNA pregenome for the viral Pol gene product. 170 31

The strain of Penicillium notatum 1 most effective for producing beta-galactosidase (see lactase 3.2.1.23), was selected out of 110 moulds belonging to 15 different species, by the test-tube microculture method. The dynamics of beta-galactosidase synthesis was investigated in P. notatum 1 during its culture by submerged method.
Acta Microbiol Pol 1990
PMID:Screening of microorganisms for improvement of beta-galactosidase production. 171 38

Sequence studies of the adenovirus 2 genome have revealed the presence of a large open reading frame (ORF) from 22.9 to 14.2 map units that is believed to encode most of the adenovirus DNA polymerase (Ad Pol). An 838-base-pair fragment (19.6-17.3 map units) containing approximately 25% of this ORF has been cloned and expressed in a beta-galactosidase-chloramphenicol acetyltransferase (lacZ-CAT) expression vector under the control of the trp-lac hybrid promoter. This recombinant vector directed the synthesis of a 58-kDa lacZ-Ad Pol-CAT fusion protein that has CAT activity. This fusion protein was easily purified by affinity chromatography in which chloramphenicol, the substrate for CAT, was covalently bound to a matrix. Antisera were prepared against the purified 58-kDa lacZ-Ad Pol-CAT fusion protein and were found to react specifically with the 140-kDa Ad Pol by ELISA and immunoblot analysis. In addition, these antisera recognized 120- and 29-kDa polypeptides in immunoblot analysis of partially purified terminal protein precursor (pTP)-Ad Pol complex. The exact nature of the 120- and 29-kDa polypeptides is not known, but they may be breakdown products of Ad Pol. Although the lacZ-Ad Pol-CAT fusion protein is not active in any of the Ad Pol enzymatic reactions, antibody against the prokaryotic fusion protein should be useful for screening bacteria harboring plasmids that have been constructed to express the entire Ad Pol ORF.
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PMID:The 140-kDa adenovirus DNA polymerase is recognized by antibodies to Escherichia coli-synthesized determinants predicted from an open reading frame on the adenovirus genome. 258 Dec 53

Monoclonal antibodies were prepared against the avian myeloblastosis virus reverse transcriptase. These monoclonal antibodies specifically immunoprecipitated the alpha and beta subunits of the reverse transcriptase molecule, as well as the Pr180gag-pol precursor protein present in virus-infected cells. In addition, these monoclonal antibodies inhibited the DNA polymerase activity associated with the reverse transcriptase molecule but not the RNase H activity. The monoclonal antibody preparations were specific for the amino-terminal portion of the protein, as determined by the immunoprecipitation of a reverse transcriptase-beta-galactosidase fusion protein produced in Escherichia coli by molecular cloning procedures.
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PMID:Production and characterization of monoclonal antibodies against avian retrovirus reverse transcriptase. 618 37

Alkaline phosphate, catalase and beta-galactosidase activities of Vibrio et tor were decreased after acquisition of resistance towards rifampicin. Zn2+, Mn2+ and EDTA inhibited alkaline phosphatase which is most active with p-nitrophenylphosphate as substrate while Mg2+ was found to suppress alkaline phosphatase activity. Removal of EDTA however, restores the original activity. Rifampicin could not induce mutation of lactose nonfermenting Vibrio el for cells allowing them to grow on lactose as sole carbon source, z-galactosidase which is a constitutive enzyme in this case is repressed by glucose. This repression is overcome by cAMP.
Acta Microbiol Pol 1982
PMID:Studies on alkaline phosphatase, catalase and z-galactosidase in Vibrio el tor under normal and rifampicin resistant conditions. 618 76

Among 47 tested yeast strains, belonging to different genera, only two cultures of Kluyveromyces fragilis and Fabospora fragilis showed beta-galactosidase activity in shaken flasks. Three types of extraction were used to release the enzyme from K. fragilis cells: solvent and detergent extraction, freezing and thawing extraction, and mechanical disintegration prior to extraction, using Triton X-100. The results indicate that the highest yield could be obtained by mechanical disintegration of cells. Factors affecting the enzyme production were studied using fermentation media of different chemical composition. The medium containing lactose, salts and yeast extract with initial pH 7.0 was selected as the best for enzyme production. Monobasic ammonium phosphate (2.0 g/dm3) was found to be the best inorganic nitrogen source for enzyme production. The effect of phosphorus level was also studied.
Acta Microbiol Pol 1994
PMID:Selection of strain, culture conditions and extraction procedures for optimum production of beta-galactosidase from Kluyveromyces fragilis. 752 16

To examine whether the epidermal growth factor (EGF)-like domain Pro47-Asp87 is involved in the interaction of tissue plasminogen activator (t-PA) with platelets, we have expressed this domain in E. coli. The peptide fragment was produced from a plasmid expression vector as a fusion protein with beta-galactosidase Met1-Val444 at high yield in eight clones of E. coli. The fusion protein was purified and subjected to mild acid hydrolysis with formic acid, then the peptide Pro47-Asp87, identified by immunoblotting using specific antibodies to t-PA, was isolated by HPLC. After incubation with blood platelets spin labelled with 16-doxylstearic acid or 5-doxylstearic acid, the Pro47-Asp87 peptide fragment reduced fluidity of the membrane lipid bilayer to the same extent as did intact t-PA as indicated by ESR measurements. Our data suggest that the EGF-like domain of t-PA can directly interact with blood platelets and thus it seems to contain those sites of the t-PA molecule that bind the platelet membrane components.
Acta Biochim Pol 1994
PMID:The epidermal growth factor-like domain from tissue plasminogen activator. Cloning in E. coli, purification and ESR studies of its interaction with human blood platelets. 803 Mar 71

The mutagenic activity of captan and captafol was tested using Ames strains and strains showing an SOS response. Captafol was mutagenic in S. typhimurium strain TA102 (uvr+) and captan in strain TA104 (uvrB). Both captan and captafol elicit damages in DNA recognized by correndonuclease II, as shown by the repair test, and induced the SOS repair system in E. coli PQ37 (uvrA) strain. Only captafol induced the SOS system in PQ35 (uvr+). The lack of induction of beta-galactosidase at nonpermissive temperature in E. coli MD332 (dnaCs uvrA) strain showed that neither chemical was able to produce DNA breaks. In V79 Chinese hamster fibroblasts higher induction of c-mitosis by captafol than by captan (22% and 15% over the control, respectively) was accompanied by a higher decrease in nonprotein sulfhydryl groups, mainly GSH (41% and 77%, respectively). The content of protein sulfhydryl groups was decreased by either fungicide to a similar extent.
Acta Biochim Pol 1994
PMID:The effects of captan and captafol on different bacterial strains and on c-mitosis in V79 Chinese hamster fibroblasts. 803 Mar 74

Inhibition by ethanol of the activities of lysosomal exoglycosidases in stomach, small intestine, liver and brain of rats exposed to cadmium (Cd2+) was determined. Out of the glycosidases tested the most distinct effect of Cd2+ and ethanol administered to the rats in vivo was observed in the small intestinal mucosa in a decreasing order: N-acetyl-beta-hexosaminidase, beta-galactosidase and alpha-fucosidase.
Acta Biochim Pol 1995
PMID:Influence of ethanol on the activity of glycosidases in rats exposed to cadmium (Cd2+). 858 79

The activity in vivo of HIV-1 proteinase (PR) was analysed in the baculovirus expression system, using eight different constructs of the prt gene under the control of polyhedrin (PH) promoters of various strengths. None of the active PRs was expressed in substantial quantities, and only PH-fused and/or non-functional PR mutants accumulated in high amounts in insect cells. However, enough PR activity was generated from a lengthened PR construct in insect cells to process Gag polyprotein substrate co-expressed in the same cells in trans. Fusion of the first 58 residues from the PH sequence to the PR N terminus did not significantly change its activity and specificity of cleavage of the Gag substrate. When analysed under mild denaturing conditions, PH-fused or unfused full-length PR point mutants, as well as PH-fused or unfused C-terminal deletion mutants, showed a propensity to multimerize, with a predominant occurrence of dimers. The incorporation of PR into Gag particles was studied using eight Gag-PR fusion constructs, all containing a non-functional PR mutant. The PR domain was fused to the C-terminal p6 domain of Gag (p6gag), or translated in frame with NCp7 (as in frameshifted Gag-Pol polyprotein) and followed by downstream sequences of increasing lengths from the Pol domain or the bacterial beta-galactosidase. The results suggested that the presence of the p6gag domain was detrimental to the encapsidation of polyprotein-embedded PR.
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PMID:Proteolytic activity in vivo and encapsidation of recombinant human immunodeficiency virus type 1 proteinase expressed in baculovirus-infected cells. 901 Feb 96


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