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)

Human cytomegalovirus (HCMV) is a major opportunistic pathogen in immunocompromised individuals. Current therapies target viral DNA replication and accumulate mutations that yield cross-resistance among the approved drugs. A novel, non-nucleoside inhibitor of HCMV replication, PD0084430, was identified in a screening assay using the HCMV beta-galactosidase recombinant RC256. The EC(50) for PD0084430 by inhibition of beta-galactosidase production is 1+/-0.7 microM. This antiviral activity was confirmed by yield reduction and plaque reduction assays using HCMV strain AD169. The TC(50) of PD0084430 as measured by (4C)thymidine incorporation is approximately 30 microM and by XTT is approximately 90 microM. The TC(50) for inhibition of cellular proliferation is approximately 20 microM. Time of addition experiments displayed a similar drop in efficacy for both PD0084430 and GCV when added after the onset of viral DNA replication. The transcomplementation assay for viral DNA replication, using a transfected ori(Lyt) containing plasmid, confirmed that viral DNA synthesis was inhibited at the same concentrations that showed antiviral activity. Western blots showed no apparent block of immediate early or early gene expression. Two ganciclovir (GCV) resistant isolates of HCMV tested showed no cross-resistance to PD0084430. These data suggested a potentially promising novel compound that inhibited HCMV at or before viral DNA replication. However, in vivo testing in mice dosed either orally or intraperitoneally showed rapid glucuronidation on the -OH group. SAR studies on this backbone showed that the -OH group was essential for the antiviral activity in vitro.
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PMID:PD0084430: a non-nucleoside inhibitor of human cytomegalovirus replication in vitro. 1167 46

The growing use of reporter genes in a model transgenic system has been a fundamental approach of biology, but the strategy of transgenic embryo selection prior to transfer to foster mothers may greately increase the efficiency of transgenic livestock production. This study was conducted to assess the possibility of beta-galactosidase (beta-gal)-labeled transgenic rabbit embryo production. Rabbit zygotes were obtained from superovulated females after mating. Zygotes were microinjected into male pronuclei with pCMV-lacZ or SV40-lacZ constructs; while some embryos were co-injected with the scaffold attachment sequences--SAR. Embryos from control non-injected and microinjected groups were cultured in vitro. After 24, 48, 72, or 96 h of culture the embryos were stained with X-gal for beta-galactosidase. Transgenic embryos produced by pronuclear injection showed a discrete pattern of beta-galactosidase expression. The percentage of transgenesis with pCMV-lacZalone was 1.5, but with SAR sequences it increased to 4.2. In the case of SV40-lacZ construct, the efficiency of transgenesis was 2.3% and 4.1%, respectively. The mosaicism was 66.7% for all embryos injected with both constructs with or without SAR. The highest numbers of 100%-transgenic (non-mosaic) embryos were found in the group co-injected with SV40-lacZ and SAR. Transgenesis was seen as early as 24 h after injection, in four-cell embryos. Most of the microinjected embryos showed delayed development as compared with control. It was concluded that lacZ may serve as a reliable reporter for early transgenic embryo selection in order to produce transgenic animals.
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PMID:Expression of microinjected reporter gene lacZ during first cleavages of rabbit embryos. 1259 37

We describe the development of an efficient expression system suitable for the stable expression of recombinant genes in Chinese hamster ovary (CHO) cells using the human interferon beta SAR element. The insertion of two copies of the human interferon beta SAR element at the 5' and 3' flanking regions of the beta-galactosidase reporter gene increased the frequency of beta-galactosidase positive colonies by up to 75% and enhanced beta-galactosidase expression by 15- to 20-fold after G418 selection or 30- to 40-fold at the initial stage of the MTX selection procedure. Deletion analysis showed that the whole DNA regions of the human interferon beta SAR element are required for beta-galactosidase expression enhancement. The developed expression system was also highly effective at enhancing the stable expression of two therapeutically important proteins, namely, erythropoietin (EPO) and hepatocyte growth factor (HGF). We isolated stable colonies with expression levels of 47 microg/10(6) cells/day for EPO and 13 microg/10(6) cells/day for HGF, suggesting that the developed expression system based on the human beta SAR element is suitable for expressing high levels of recombinant proteins in CHO cells.
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PMID:Efficient selection of stable chinese hamster ovary (CHO) cell lines for expression of recombinant proteins by using human interferon beta SAR element. 1593 76