Expression of Core Domain of Porcine Zona Pellucida 3β in E.coli

To obtain the recombinant core domain of porcine zone pellucida 3β （cZP3β） for the further research on its functions Methods The nucleotide sequence region from 44 to 306 codons of pZP3β entire eDNA was obtained by PCR and then was cloned into pET-3c vector. After being identified, recon was transformed into E.coli BL21 （DE3） pLysS and then induced by IPTG. Results The recombinant cZP3β was expressed in E. coli up to 15% of total cellular proteins, and was made sure by Western blot analysis. Conclusion The research on expression of core domain of pZP3β could benefit to further investigation of its immunogenicity and the development of antigen preparation.

Expression of Nonfusion Extracellular Porcine Zona Pellucida Protein 3β in E.coli

Objeetive To obtain the recombinant non fusion extracellular porcine zona pellucida protein 3β （pZP3β） in E.coli Methods By modificated the transition initiation region （TIR） in primers, synthetic nucleotide was gained by PCR. Such gene was cloned into pET-3c vector and transformed into E.coli BL21（DE3）pLysS. Results The recombi.ant nonfusion extracelhtlar pZP3β was expressed in E.coli to 10% of total cellular proteins, and identified by the Western blot method. Conclusion Modification of nucleotide without changing amino acid sequences is an effective means to increase non fusion expression rate of recombinant proteins, such as pZP3β in E. coll.

High-level Expression and Purification of Human Zona Pellucida huZP3a^(22-176) and huZP3b^(177-348) Peptides in Escherichia coli

Objective To try making huZP3a^22-176 and huZP3b^177-348 polypeptides （representing an intact huZP^322-348 protein without its N-terminal signal peptide and C-terminal transmembrane domain ） express in E. coli at a higher level Methods The cDNAs encoding huZP3a and huZP3b were obtained with PCR method. The pBV221 plasmid was used to construct thermo-inducible recombinant expression vector. Purification of two target expression products employed an improved method of preparative gel polyacrylamide gel electrophoresis. Results Two polypeptides of recombinant huZP3a （rhuZP3a） and recombinant huZP3b （rhuZP3b） were all expressed respectively in an E. coli BL21（DE3）pLysS strain at a higher level, which were recognized by two specific polyclonal antisera in Western blotting test which recognize a linear B cell epitope present in rhuZP3a or rhuZP3b respectively. Using the shake-flask method, approximately 5 mg of rhuZP3a and rhuZP3b with more than 95% relative homogeneity were harvested from 1 L culture respectively. Conclusion The availability of two rhuZP3 polypeptides will help in detecting the immunogenicities of rhuZP3a and rhuZP3b through animal experiments and confirming the function domain of non-glycosylated huZP3 to induce acrosome reaction in vitro.

Monoclonal Antibodies Reveal Novel Localization of SPAG11E in Spermatozoa and the Antifertility Potential of SPAG11E Motifs

Objective: SPAG11E is the first β-defensin that has been reported to activate Ca;uptake and sperm motility. However, the exact subcellular localization and interaction of SPAG11E with sperm remain controversial because of the lack of qualified antibody tools. SPAG11E is also a potential male antifertility target because SPAG11E fragment conjugated with a carrier protein exhibits male contraceptive vaccine potential.However, the fine B-cell epitope motifs of SPAG11E have not been analyzed, which hampered further exploration of the potential target.Methods: Polyclonal and monoclonal antibodies（mcAbs） of mature SPAG11E were raised and qualified with Western blotting. Subcellular localization of SPAG11E was revealed by Western blotting, immunohistochemistry staining, and electron microscopy. B-cell epitopes of rat SPAG11E were mapped by Western blotting using polyclonal and mcAbs. Based on the conservation of the identified epitope motifs between rat and mouse SPAG11E, antifertility potential of the epitope motifs was evaluated by the offspring of the males compromised with specific mcAbs.Results: SPAG11E antibodies of high quality were obtained and all B-cell epitope motifs of rat SPAG 11 E were mapped, in which conserved epitope motifs of SPAG11E in various species were discovered. The epitope motifs recognized by mcAbs were identified respectively. With mcAbs, rat SPAG11E was proved to be expressed in the caput region of epididymis. A novel finding was that SPAG 11 E was located in the flagella and nuclei of sperm as revealed by immunoelectron microscopy. In addition, the males treated with mcAbs（3#-1 and 10#B4） showed apparently fewer offspring.Conclusions: SPAG11E revealed a β-defensin with novel localization in sperm flagellum and nucleus with qualified antibodies. All B-cell epitope motifs of rat SPAG11E were determined, and the antifertility potential was proved by corresponding mcAbs.