Vectors for expressing bovine growth hormone derivatives.

摘要

(1) Selectable and autonomously replicating recombinant DNA expression vector is new when it contains (a) a runaway replicon; and (b) a transcriptional and translational activating sequence in the reading frame of a gene coding for a bioactive bovine growth hormone (BGH) deriv. The gene is one of 6 defined nucleotide triplet sequences, each carrying a DNA sequence coding for amino acids 9-191 of BGH linked to a defined DNA sequence coding for a translational stop signal. (2) The BGH deriv. coded for by the vector is of formulae (I)-(II) and is new. Met-Phe-Pro-Ala-Met-Ala-R2 (I) Met-Asp-Asp-Lys-R3 (II) Met-Asp-R3 (III) (R2=natural amino acid sequence of BGH from 6th amino acid to N-terminus; R3=natural amino acid sequence of BGH from N-terminal (first) phenylalanine). (3) Host cell transformed with a vector as defined above is new. (4) Plasmid pCZ103 is also new. (5) Prodn. of an intracellular highly homogeneous species of proteinaceous granule comprises (a) transforming a competent cell with a selectable and autonomously replicating recombinant DNA expression vector comprising a runaway replicon together with a transcriptional and translational activating sequence in the reading frame of a nucleotide sequence coding for a functional polypeptide (IV). The sequence contains a translational stop signal immediately adjacent to, and downstream from, the nucleotide triplet coding for the carboxy terminus of (IV); and (b) culturing the transformed cell under conditions suitable for gene expression and activation or induction of the runaway replicon. -