| 摘要 |
<p>Hybrid promoter/operators are prepared and inserted into plasmids which are used to transform E. coli. They are arranged to control expression (by a gene in the plasmid) of a desired heterologous peptide e.g. human growth hormone, HGH. Each hybrid promoter/operator has (a) a promoter operator fragment which is capable of being chemically induced, and (b) a fragment which includes the -35 consensus sequence and the 5 min flanking region thereof of a promoter having a high signal strength. The fragments (a) and (b) are appropriately spaced to form an operable hybrid promoter which is both inducible and of high signal strength (properties not naturally found together). E.g. one hybrid operator/promoter has a sequence from upstream of position -22 of the trp promoter (of high strength) coupled to a sequence downstream from position -19 of the lac promoter operator (inducible). This was used to control a gene for HGH in a plasmid pHGH807tacl. E. coli was transformed therewith and cultured. Production of HGH (rapid owing to the strong promoter fragment) was induced by addition of isopropyl- beta -D-galactoside to the culture medium.</p> |
