Human immunodeficiency virus type-1 p24 sequence from an Indian strain: expression in Escherichia coli and implications in diagnostics

Abstract

A 637-bp fragment, corresponding to the p24 human immunodeficiency virus (HIV) core protein from the gag ORF, was PCR amplified from DNA isolated from peripheral blood mononuclear lymphocytes (PBML) of an asymptomatic HIV-1 seropositive human subject from Bombay and cloned into PCRScript SK(+). The nucleotide sequence revealed highest homology (98.6%) with the consensus sequence of the HIV-1 B subtype. The 637-bp KpnI-HindIII fragment was cloned downstream from a His₆ tag in the pQE30 vector under the control of phage T5 promoter leading to production of a 6XHis-p24 fusion protein in Escherichia coli. It showed an approx. 24-kDa band by SDS-PAGE. The recombinant p24 reacted with serum samples from HIV-infected subjects when tested by Western blot and ELISA.