Expression of phosphoprotein P2 of Cysticercus cellulosae in Pichia pastoris and its application / 生物工程学报

Cysticercosis is caused by the metacestode form of Taenia solium-Cysticercus cellulosae and it causes great economic losses and threatens the people's health. There are some problems on how to control cysticercosis, in order to resolve the key problem that the native antigen to diagnose and prevent cysticercosis is very limited and is not satisfied, Pichia pastoris Expression System was used to express recombinant P2 protein. The interested P2 gene was got by digesting the pGEM - P2 vector using restriction endonuclease, then it was inserted into the secretory pPIC9K Pichia pastoris expression vector and transformed into E. coli. Positive recombinant plasmids were selected sequenced and named pPIC9K-P2 and it was linearized by Sal I and Bgl II, then the linear DNA transfored into Pichia pastoris GS115 by electroporation. The recombinant expression vector pPIC9K - P2 integrated into GS115 via homologous recombination between the transforming DNA and regions of homology within the genome. The transformants were screened for multicopy recombinants using G418 and were distinguished for Mut phenotypes by MD and MM. Two different phenotypes were generated-HIS+ MUT+ (Methanol utilization plus) and HIS+ MUT(S) (Methanol utilization slow). PCR analysis of the multicopy recombinants indicated that the P2 gene was integrated within the genome of pichia Pastoris. The multicopy recombinants were named GS115/pPIC9K - P2HIS+ MUT+ and GS115/pPIC9K-P2HIS+ MUT(S), both HIS+ MUT+ and HIS+ MUT(S) were induced with methanol. The results of SDS-PAGE and Western blot demonstrated that the culture supernatant of the induced Pichia pastoris contained P2 protein which was accumulated up to 33 % of total proteins in the culture supernant and its molecular weight is 12.6kD. The results of the clinical study indicated that the expression P2 protein could be used to diagnose human cysticercosis and swine cysticercosis as diagnosis antigen.

Study on the expression of E2 gene of classical swine fever virus in Pichia pastoris and the immunological activity of its expression product / 生物工程学报

E2 gene of classical swine fever virus (CSFV) was cloned into secretory pPIC9K Pichia pastoris expression vector. After being linearized by digestion, the vector was transformed into Pichia pastoris by electroporation to integrate with the genome, the transformants with high copies were screened by G418 and were induced to express with methonal. The results of SDS-PAGE and Western blot demonstrated that the supernatant of the induced P. pastoris culture contained protein E2. The results of the study on the immunological activity indicated that the protein E2 expressed in P. pastoris can elicit animal bodies to produce antibodies against protein E2.

Cloning of the major antigen region of E2 gene of hog cholera virus and expression in Escherichia coli / 生物工程学报

The major antigen region of E2 gene of Hog Cholera Prevalent Strain (Guangxi Yuling Strain) and Chinese Hog Cholera Lapinised Virus (C-strain) derived from hog and rabbit spleen tissue, was amplified by reverse transcription polymerase chain reaction(RT-PCR) and the nested Polymerase Chain Reaction (nPCR). After the amplified fragments were cloned into the expression vector pPROEX-HTb, the recombinant plasmids pPROEX-GXYL and pPROEX-C were obtained. The insert position, the size and the reading frame were right by PCR, restriction digestion and the sequence analysis. SDS-PAGE indicated that both of the reciepient germs transducted and induced by the recombinant plasmids pPROEX-GXYL and pPROEX-C could express the major antigen region of E2 gene. Western-blot indicated that the expressed antigen protein could be recognized by the positive serum of CSFV.