[Preliminary study on expression of Leishmania donovani antigen gene in E. coli]

We constructed previously the expressing library of Leishmania donovani genomic DNA with lambda gt11 as vector. In this paper, 2 x 10(4) phages were plated on E. coli Y1090r-, and screened with a rabbit antiserum prepared by immunization with Leishmania donovani promastigotes. Bound antibodies were detected using alkaline phosphatase labeled anti-rabbit antibodies. A positive expressing clone was detected and transferred into E. coli Y1098r- to prepare lysate, a 39 kDa polypeptide in E. coli Y1089r-lysate was recognized by anti-Leishmania donovani serum. The result indicated that the 39 kDa polypeptide which was not fused with the major portion of beta-galactosidase existed disconnectedly. This finding remained to be further studied.