RESUMEN
A cDNA for the disintegrin domain (hf279) was isolated by PCR from human testis cDNAs. DNA sequencing indicated that hf279 cDNA encoded 93 amino acid residues, and it was identical with the reported sequence of fertilin beta. An expression plasmid, pGEX hf279, was constructed by inserting hf279 cDNA into plasmid pGEX-4T-2 containing gst gene. The expression plasmid was introduced into E.coli BL21(DE3) cells and a substantial amount of soluble fused protein GST-HF93 was obtained by the expression strain HF93/BL21 induced with IPTG. SDS-PAGE analysis revealed that the GST-HF93 fusion protein had an apparent molecular weight of 38 kD and accumulated up to 50% of bacterial soluble proteins. The fusion protein was purified by glutathione S-transferase (GST) Sepharose 4B column (purity 90%) and digested by thrombin to obtain the purified HF93 peptide (purity 80%). Polyclonal antibodies were obtained from the serum of miceimmunized with purified HF93 which was isolated by GST Sepharose 4B column and SDS-PAGE. ELISA and Western blot analysis showed its specificity to HF93. Therefore this antibody can be used in further studies on the function of HF93.
RESUMEN
To investigate the expression of CTP encoding gene in the methylotropic yeast, pichia pastoris and the possibility of CTP acting as an antifertility vaccine or anti-cancer vaccine, we strung two, three or four CTP cDNA to construct CTP polymeric cDNA in order to enhance the immunogenicity of the CTP. Then, the recombinant genes were subcloned into a pichia pastoris expression vector pPIC9K to construct pPIC9K-(hCGbeta-CTP37)n(n = 2,3,4). After identified by restriction endonuclease digestion and DNA sequencing, the recombinant vectors were linearized and transferred into GS115 by electroporation. The induced culture supernatant was precipitated by PEG6000 and the precipitate was washed by 75% alcohol. SDS-PAGE and RIA analysis suggested GS115 expressed the recombinant genes successfully and the recombinant protein had anti-hCG antibody binding activity. In addition, ANTHEPROT 4.3 software was used to analyze the protein structure of CTP quadrigeminum. We found that CTP quadrigeminum had similar secondary structure with hCGbeta, but the speciality of antigen better than that of the latter. Therefore, we conclude that this study prepared basic necessary data for developing antifertility vaccines or anticancer vaccines basing on hCGbeta--CTP37.
Asunto(s)
Gonadotropina Coriónica Humana de Subunidad beta/metabolismo , Fragmentos de Péptidos/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Western Blotting , Gonadotropina Coriónica Humana de Subunidad beta/genética , Electroforesis en Gel de Agar , Electroforesis en Gel de Poliacrilamida , Humanos , Fragmentos de Péptidos/genética , Pichia/genética , Reacción en Cadena de la Polimerasa , Estructura Secundaria de Proteína , Radioinmunoensayo , Proteínas Recombinantes/genética , Programas InformáticosRESUMEN
To study the expression of hFSH in insect cells, the cDNA encoding the hFSH beta chain was cloned by overlapping-PCR using human chromosome DNA extracted from placental tissue as template. Then we constructed expression vector pVL1393/hFSH beta using an unfused protein nuclear polyhedrosis virus (AcNPV) expression vector. The insect cells (SF9) were cotransfected with the expression vector and nuclear polyhedrosis linearized virus DNA, and recombinant viruses AcNPV-hFSH beta were collected. The beta subunit of hFSH expressed in plasma of the SF9 cells was detected by Western blot analysis, and showed apparent molecular masses of 21 kDa. After coinfecting SF9 cells with recombinant viruses AcNPV-hFSH beta and AcNPV-hCG alpha, secreted heterodimer of hFSH was detected by Western blot under non-reducing conditions. The apparent molecular weight of heterodimer was about 33 kDa.