An Expression Release
System for Heterogeneous Proteins in E.coli Mediated by
the kil Gene
TONG Qin, ZHANG Hui-Tang, YANG Yun-Gui, YANG Sheng-Li, GONG
Yi*
( Research Center of Biotechnology, Shanghai Institute for Biological
Sciences, the Chinese Academy of Sciences, Shanghai 200233, China
)
Abstract An
expression release system for heterogeneous proteins in Escherichia coli
mediated by the colicin release gene(kil gene) was constructed. The
system is based on the ability of the Kil protein to release periplasmic
proteins into the growth medium. β-lactamase, an E.coli periplasmic
protein, and prolyl endopeptidase (PEP), a periplasmic protein of Aeromonas
punctata subsp.punctata were used as report proteins. Commonly,
these two proteins are seldom released into the growth medium. The results
indicated that the released amounts of the β-lactamase and of the prolyl
endopeptidase were nearly 5 fold and 4 fold than control,respectively.
Key words kil gene； excretion； β-lactamase； prolyl endopeptidase
*Corresponding author： Tel, 86-21-64700892-371； Fax, 86-21-64700244； e-mail, [email protected]