The present study aims to obtain soluble bacterial antigens expressed by Pichiapastori and to probe the differential gene expression of prokaryotic antigens in eukaryotic cells. The genes ag85a,esat6, and rdesat6 from Mycobacterium tuberculosis and the gene of psaa tromStreptococcus pneumoniae were amplified by polymerase chain reaction individually and then cloned into the vector pPic9k. The gene expression of the four antigens: Ag85a,ESAT6,rdESAT6 and PsaA were induced in Pichiapastoris and the four secreted proteins were purified by using either ion exchange or Ni-NTA column. The highest protein expression level in Pichiapastoris,about 200 mg/L,was obtained by cloning the psaa gene of Streptococcus pneumoniae into the pPic9k vector. Minor difference was shown in the expression of the three different genes of Mycobacterium tuberculosis ,ag85a,esat6,and rdesat6. The protein expression levels of rdESAT, Ag85a and ESAT6 were 2 mg/L,l mg/L,and under 0. 5 mg/L respectively. In addition.N-linked glycosy-lation was found in both ESAT6 and rdESAT6 proteins. The difference of the protein expression of the genes of Mycobacterium tuberculosis was minor. However, N-linked glycosylation was found in both ES-AT6 and rdESAT6 proteins,not the Ag85a protein in Pichiapastoris expression System.
Pichiapastorisprokaryotic protein antigensdifferential expression
NETL
NSTL
维普
万方数据
