Four pairs of HBV surface antigen genes, in which the preS region was partially deleted,were constructed by the polymerase chain reaction (PCR). The comparison of the levels of the expression in mammalian cells of the...Four pairs of HBV surface antigen genes, in which the preS region was partially deleted,were constructed by the polymerase chain reaction (PCR). The comparison of the levels of the expression in mammalian cells of these genes and the ones constructed before, and the properties of these gene products showed that the missing of a part of the preS region did not affect the overall spatial structure of the S region and the surface localization of the preS region. The removal of the preS1 retention sequence (a. a. 2-19) alleviated significantly the shelter of the major antigenic determinants in the S region by the preS sequence. It was found that the long preS region seriously impaired the secretion of the surface antigen proteins from mammalian cells. In addition to the previously reported preSl retention sequence, the preSl sequence (a.a. 48-65) may also inhibit the secretion of the surface antigen proteins, whereas the preS2 region exerts no major influence on the retention of the large surface antigen protein. One of the expressed surface antigen proteins, in which the preSl sequence (a.a. 21 - 47) and the S region were directly fused, deserves further study and may be developed into a new HBV vaccine which contains the preSl binding site for hepatocyte receptors due to its stability, fine secretability and strong preS1 antigenicity.展开更多
基金Project supported in part by National 863 Research Grant of China and Public Health Service Grants from the National Institutes of Health of the United States.
文摘Four pairs of HBV surface antigen genes, in which the preS region was partially deleted,were constructed by the polymerase chain reaction (PCR). The comparison of the levels of the expression in mammalian cells of these genes and the ones constructed before, and the properties of these gene products showed that the missing of a part of the preS region did not affect the overall spatial structure of the S region and the surface localization of the preS region. The removal of the preS1 retention sequence (a. a. 2-19) alleviated significantly the shelter of the major antigenic determinants in the S region by the preS sequence. It was found that the long preS region seriously impaired the secretion of the surface antigen proteins from mammalian cells. In addition to the previously reported preSl retention sequence, the preSl sequence (a.a. 48-65) may also inhibit the secretion of the surface antigen proteins, whereas the preS2 region exerts no major influence on the retention of the large surface antigen protein. One of the expressed surface antigen proteins, in which the preSl sequence (a.a. 21 - 47) and the S region were directly fused, deserves further study and may be developed into a new HBV vaccine which contains the preSl binding site for hepatocyte receptors due to its stability, fine secretability and strong preS1 antigenicity.
