Expression and properties of prochymosin derivatives containing extensions of various length in the pro-part.
A series of hybrid prochymosin derivatives containing portions of the simian virus 40 small-t antigen in the pro-part was constructed. Portions comprising 93, 63, 47, 12, and 1 amino acid (aa) from the N terminus of the small-t antigen were separately fused via eight polylinker-encoded amino acids to a prochymosin product commencing with the 5th aa of the pro-part. All the DNAs coding for the hybrid proteins were put under pL-promoter control in the expression constructs. Expression revealed that only fusion of the 47-aa or 12-aa stretch of the small-t antigen to prochymosin gave stable protein products and that only the latter one allowed the hybrid prochymosin to be activated to chymosin. The products containing 93 aa and 63 aa of small-t antigen were unstable and degraded. Complete removal of the small-t antigen portion led to mRNA instability, probably owing to inefficient initiation of translation.
Kaspar
P
P
Institute of Molecular Genetics, Czechoslovak Academy of Sciences, Prague.
Fábry
M
M
Sedlácek
J
J
Zadrazil
S
S
D001483:Base Sequence; D012085:Chymosin / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004792:Enzyme Precursors / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D005814:Genes, Viral; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013539:Simian virus 40 / Q000235:genetics
D004792:Enzyme Precursors; D004262:DNA Restriction Enzymes; C032443:prorennin; D012085:Chymosin