Expression of the Superactive [Lys17,18,Glu21]-Glucagon
in E. coli
WEN Chong-Wei, GAN Ren-Bao*,
ZHU Shang-Quan*
( Institute of Biochemistry and Cell Biology, Shanghai
Institutes for Biological Sciences,
the Chinese Academy of Sciences, Shanghai 200031, China )
Abstract One of the most important findings in
structure-function studies on glucagon by means of chemical synthesis is the
discovery that [Lys17,18,Glu21]-glucagon had higher
biological activity than native glucagon. This mutant of glucagon was called
superactive glucagon (SA-glucagon). In the present work, the possibility to
obtain SA-glucagon by means of genetic engineering was studied. The gene of
SA-glucagon (SAG) was obtained by PCR from a constructed recombinant glucagon
plasmid, pAGluT. A secretory expression vector harboring SAG, pBLSG7,
containing P
peptide was constructed. In expression studies after transformation of pBLSG7
into E. coli BL21, it was found that the expression yield of SA-glucagon
reached 3.65 mg/L (A
proteins in the culture medium under shaken flask conditions. In addition, the
influence of induction temperature and of E. coli strain on the
expression yield of SA-glucagon was also studied.
Key words genetical engineering;
glucagon; SA-glucagon; P
Corresponding
author:
ZHU Shang-Quan:
Tel, 86-21-64374430-5283; Fax, 86-21-64338357; e-mail, [email protected]
GAN Ren-Bao: Tel, 86-21-64374430-5325; Fax, 86-21-64338357; e-mail, [email protected]