title: High level expression of bikunin in Pichia pastoris by fusion of human serum albumin.
abstract: Bikunin is a proteoglycan exhibiting broad-spectrum inhibitory activity against serine proteases and could potentially suppress tumor cell invasion and metastasis. Here, we have successfully expressed recombinant human bikunin (rh-bikunin) in Pichia pastoris and also established the purification procedure. Different fusion genes of h-UTI and domain I, domain I and domain II, domain I, domain II and domain III of human serum albumin (HSA) were inserted into expression vector pPICZαA. After expressed in shake flask, rh-bikunin was produced in an 30-L fermenter and purified by affinity chromatography and cation exchange chromatography. The final expression levels were 200 mg/L and we got totally 1.08 g (3650 IU/mg) of active purified rh-bikunin (purity is 98%) from 20 L of fermentation broth. The rh-bikunin consists of unique form with molecular masses of 25 kDa, and has the same N-terminals sequence as human native bikunin. This study provided a new method for high level expression of active rh-bikunin by using HSA as fusion parter.
authors.affiliation: Faculty of Bioindustry, Chengdu University, Waidong Shilingzhen, Chengdu, 610106, China. wangwei@cdu.edu.cn.
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Gou
authors.forename: Yu-Ying
authors.initials: YY
authors.lastname: Liu
authors.forename: Qi-Lei
authors.initials: QL
authors.lastname: Chen
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Tang
authors.forename: Da-Yu
authors.initials: DY
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Zou
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang