A Recombinant Monomeric
Human Insulin Mutant with Resistance to Trypsin：Design, Preparation and Characterization
ZHANG Hong, CHEN-Yan, FENG You-Min*
( State Key Laboratory of Molecular Biology, Shanghai Institute of
Biochemistry, Shanghai Institutes for Biological Sciences,the Chinese Academy
of Sciences, Shanghai 200031, China )
Abstract By using a
gapped duplex DNA method, the four amino acids on the B chain of insulin, i.e.
B22Arg, B28Pro, B29Lys and B30Thr, were mutagenized simultaneously into B22Asp,
B28Lys, B29Pro and B30Lys, respectively. The recombinant［B22Asp、B28Lys、B29Pro、B30Lys］human insulin was obtained
simply by the treatment with trypsin of the precursor that was expressed in
yeast. This human insulin analog had only 6% of receptor binding activity as
that of the porcine insulin, but retained 50% of in vivo biological
activity, compared with the latter. The self-association ability of the mutant
measured through FPLC gel filtration chromatography showed that it was in
monomeric state. As a monomeric insulin analog with resistance to the trypsin
digestion, this compound may be promising in practical application.
Key words mutant insulin； monomeric insulin； protein engineering
*Corresponding author：Tel,86-21-64374430；Fax,86-21-64338357；e-mail,[email protected]