Xiong XH, Zhao HL, Xue C, Zhang W, Yang BF, Yao XQ, Liu ZM. Construction and evaluation of anti-gastrin immunogen based on P64K protein.
World J Gastroenterol 2006;
12:2040-6. [PMID:
16610054 PMCID:
PMC4087682 DOI:
10.3748/wjg.v12.i13.2040]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To construct two kinds of anti-gastrin immunogen based on P64K protein from Neisseria meningitids and to compare their immunogenic effect.
METHODS: G17P64K gene was cloned and ligated into pET28a plasmid, then transformed into BL21(DE3). After inoculation of LB medium and IPTG induction, the recombinant protein was solubly expressed at a high level.The purification of G17P64K fusion protein was similar to that of P64K. An initial step of purification consisting of 30 % saturated ammonium sulfate precipitation was done. Additional fine optimizations included phenyl-sepharose, G200 Sephadex gel filtration and Q-sepharose anion exchanger chromatography. Highly purified protein was obtained and sequenced at the N-terminal amino acid residues. Polypeptide was synthesized by Fmoc solid phase chemical method and cross-linked to carrier protein P64K and DT mutant by MBS method and then the rabbit anti-gastrin 17 antibody was prepared by immunizing rabbit with cross-linked and fused protein. The titer and the activity in vitro of antibody were assessed.
RESULTS: G17P64K gene and the recombinant bacteria were obtained. After four steps purification, protein sample that has the purity above 90 % was achieved. At the 84th day after the first immunization, the titer of antibody against cross-linked protein reached 51 200. Evaluation of the antibody in vitro manifested that it had a high inhibitory activity on the growth of tumor cell SW480.
CONCLUSION: The P64K-polypeptide cross-linked immunogen immunized rabbit and achieved a higher titer antibody against gastrin 17 than the G17P64K fusion protein immunogen, which could inhibit the growth of the tumor cell SW480.
Collapse