| 摘要 |
<p>Epidermal growth factor, a naturally occurring, relatively short, single chain polypeptide, is prepared by growing methylotrophic yeast transformants containing in their genome at least one copy of a DNA sequence operably encoding EGF, in operational association with a DNA sequence encoding the S. cerevisiae alpha mating factor pre-pro sequence (including the proteolytic processing site: lys-arg), both under the regulation of a promoter region of a gene of a methylotrophic yeast, under conditions allowing expression of said DNA sequences, and secretion of EGF into the culture medium. Also disclosed are novel DNA fragments and novel recombinant yeast strains which are useful in the practice of the present invention.</p> |
