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)

We have compared the long-term stability of 2 avian non-replicative retroviral vectors in an infected permanent cell line from quail fibroblasts (QT6). Vectors NL53 and NPL, expressing both the neo and LacZ genes under control of cis-acting elements originated from avian erythroblastosis virus (AEV), are similar to each other except for the presence of the phleomycin-resistance SHble gene fused upstream the reporter LacZ gene, in NPL vector. The use of such vectors, with an uniform backbone, to infect QT6 cells, allowed us to demonstrate that stability of the beta-galactosidase activity encoded by the SHble-LacZ fusion gene remains higher than that encoded by the native LacZ gene, as determined in the same conditions of culture. Moreover, stability of the provirus was dependent on the selection pressure. Here we show that stability of beta-galactosidase activity in infected QT6 cells was obtained with high dose selection for the selectable SHble-LacZ fusion gene.
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PMID:Influence of the nature of the reporter gene and selection pressure on stability of avian retrovirus vectors. 855 47

Two metabolically engineered Escherichia coli strains have been constructed to produce the carbohydrate moieties of gangliosides GM2 (GalNAcbeta-4(NeuAcalpha-3)Galbeta-4Glc; Gal = galactose, Glc = glucose, Ac = acetyl) and GM1 (Galbeta-3GalNAcbeta-4(NeuAcalpha-3)Galbeta-4Glc. The GM2 oligosaccharide-producing strain TA02 was devoid of both beta-galactosidase and sialic acid aldolase activities and overexpressed the genes for CMP-NeuAc synthase (CMP = cytidine monophosphate), alpha-2,3-sialyltransferase, UDP-GlcNAc (UDP = uridine diphosphate) C4 epimerase, and beta-1,4-GalNAc transferase. When this strain was cultivated on glycerol, exogenously added lactose and sialic acid were shown to be actively internalized into the cytoplasm and converted into GM2 oligosaccharide. The in vivo synthesis of GM1 oligosaccharide was achieved by taking a similar approach but using strain TA05, which additionally overexpressed the gene for beta-1,3-galactosyltransferase. In high-cell-density cultures, the production yields for the GM2 and GM1 oligosaccharides were 1.25 g L(-1) and 0.89 g L(-1), respectively.
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PMID:Large-scale in vivo synthesis of the carbohydrate moieties of gangliosides GM1 and GM2 by metabolically engineered Escherichia coli. 1274 Aug 12