[Construction, expression, and identification of the gene of human anti-prostate specific membrane antigen single-chain antibody].

OBJECTIVE: To construct, express and purify human fusion proteins composed of a single-chain antibody fragment scFv that recognizes the prostate specific membrane antigen (PSMA) protein, Fdt, HA2 and tp, and to analyze the binding activity of the expressed fusion proteins. METHODS: The fusion protein genes scFv, scFv-tp, and scFv-Fdt-HA2-tp were amplified by PCR, and the genes obtained were then cloned into the expression vector pET28 and expressed in E. coli BL21. The expressed products were identified by SDS-PAGE and Western blot and purified with Ni(2+)-NTA chelating agarose. The antigen-binding activity of the fusion proteins was determined by ELISA. RESULTS: The human anti-PSMA fusion gene was successfully constructed and expressed in M15 as the inclusion body after induced with IPTG. All the target proteins expressed could bind the PSMA antigen. CONCLUSION: Fusion proteins can specifically bind the PSMA antigen. This finding contributes to the study of the targeted delivery of siRNA.