Monomeric B27 Lys Destripeptide Insulin: Semisynthesis, Characterization and Biological Activity

( Institute of
Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences,
the Chinese Academy of Sciences, Shanghai 200031, China )

Abstract
In this paper, we report the semisynthesis of B27 Lys destripeptide insulin
(B27 Lys DTrI), i.e. destetrapeptide insulin with an additional Lys residue
at the C-terminus of B-chain. B27 Lys DTrI is also monomeric as shown by gel
filtration. Its in vivo biological activity is 80% in comparison with
that of native insulin. The addition of a Lys residue at the C-terminus of
B-chain makes it possible to obtain monomeric B27 Lys DTrI from a precursor
expressed in Saccharomyces cerevesiae by tryptic hydrolysis instead of the
less efficient tryptic transpeptidation.