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)

Enhanced accumulation of human proinsulin synthesized in Escherichia coli has been achieved by inserting a short leader of homooligopeptide at the amino end of proinsulin. Out of 20 amino acid oligomers studied, (Ala)6, (Asn)6, (Cys)7, (Gln)7, (His)6, (Ser)6, and (Thr)6 leaders were the most effective, with the yield of proinsulin ranging between 6% and 26% of the total bacterial protein. These constructions were made by inserting a synthetic oligodeoxyribonucleotide duplex, coding for a small homooligopeptide, between a synthetic proinsulin gene and an eight-codon beta-galactosidase gene residue in vector pUC8. Cyanogen bromide cleavage of the 102 amino acid fused polypeptide yielded a species identical to authentic proinsulin, as judged by NaDodSO4/PAGE and radioimmunoassay.
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PMID:Short synthetic oligodeoxyribonucleotide leader sequences enhance accumulation of human proinsulin synthesized in Escherichia coli. 351 72

Thymosin alpha 1, an immune restorative polypeptide hormone, was synthesized in Escherichia coli by using recombinant DNA cloning techniques. Based on the known amino acid sequence, a gene coding for the thymosin alpha 1 polypeptide chain was designed and enzymatically assembled from chemically synthesized oligodeoxyribonucleotide fragments. The gene was ligated into plasmid pBR322 and placed under lac operon control, and N alpha-desacetylthymosin alpha 1 was expressed as part of a beta-galactosidase chimeric protein. Cyanogen bromide cleavage of this protein gave a mixture of polypeptides, among which thymosin alpha 1 activity was detected by radioimmunoassay (RIA). The E. coli product is identical with native thymosin alpha 1 isolated from calf thymus in the amino acid sequence but lacks the N-terminal acetyl group. Results of a guinea pig migration inhibition factor (MIF) assay, a terminal deoxyribonucleotidyl transferase (TdT) assay, and radioimmunoassay indicate that the N alpha-desacetylthymosin alpha 1 produced by deoxyribonucleic acid (DNA) cloning techniques has biological activity equivalent to that of the native hormone.
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PMID:Production of biologically active N alpha-desacetylthymosin alpha 1 in Escherichia coli through expression of a chemically synthesized gene. 700 28