Title:A Novel Approach for Secretion of Heterologous Proteins with Correct N-Terminal Processing by Using α-Factor Pre Sequence in Pichia pastoris
Volume: 19
Issue: 9
Author(s): Lu Shen, Zhenyun Liu, Fenli Xie, Xuerui Zhang and Shuhua Tan
Affiliation:
Keywords:
Secretion, Pichia pastoris, α-factor pre-pro sequence
Abstract: Numerous proteins have been secreted in P. pastoris by fusing the target gene with α-factor pre-pro sequence at
Kex2 endopeptidase cleavage site. However, in some instances the product cannot be correctly processed due to aberrant
cleavage by Kex2 endopeptidase such as aprotinin. In this study, an aprotinin gene was cloned into pPIC9K at the signal
peptidase cleavage site through a single NheI restriction site designed at the 3’end of the α-factor signal sequence preregion,
and transformed into GS115 host cell. By G418 resistance and ELISA assay, a high-yield recombinant was selected.
After fed-batch cultivation in a 7-L bioreactor, the product was efficiently secreted into culture medium and accumulated
up to ~ 4.7 mg L-1. MALDI-TOF/MS and N-terminal analyses confirmed its authenticity. Thus, a novel cloning
strategy for secretion of aprotinin with correct N-terminal processing in P. pastoris has been developed which can be potentially
applied to other proteins.