我国河南株丁型肝炎病毒抗原在原核细胞中的高效表达及分泌

HIGH- LEVEL EXPRESSION AND SECRETION OF CHINESE HENAN HEPATITIS DELTA ANTIGEN IN PROKARYOTIC CELLS

wo expression plasmids pETDAg and pETDAg -1 ,which contain the gene of Chinese Henan hepatitis delta antigen were constructed under the T7 Promoter,with and without terminator resepectively .The host bacteria BL21 were transformed by the two recombinant plasmids and IPTG was used to induce HDAg expression .SDS-PAGE and Western blot showed that the molecualr weights of expressed HDAg in the periplasmic space and inclusion body were 27kD and 28kD respectively; ELISA tests showed that the antigentic activity of secreted HDAg in periplasmic space is 70% of the total ,its ELISA titer and specific activity are higher than 1:32,000 and 10,000 ELISA unit/mg of protein expressed. In addition ,several anti-HDV McAbs were used to analyse the possible epitopes of this Henan strain rHDAg and to compare with that of Sichuan strain . The result showed that one anti -HDV McAb ,McAb G12 ,can not bind rHDAg of this Henan strain ,though it reacts with rHDAg of Sichuan strain very well. This may be due to some differences in the tertiarystructuer of rHDAg between Henan and Sichuan .