Shorter size of transmembrane glycoprotein of an HIV-1 isolate.

An HIV-1 strain carrying a shorter form of the transmembrane glycoprotein (TM) with a mobility of 32 kD, named KB-1, was isolated from a Japanese male hemophiliac by coculture of his peripheral blood mononuclear cells (PBMCs) with MT-2 cells and adaption to TALL-1 cells. Another HIV-1 strain, named KB-2, was isolated from his seropositive spouse by coculture of her PBMCs with MT-2 cells. The KB-2 strain carried a TM of ordinary size, with a mobility of 41 kD. The KB-1 strain carrying a truncated form of the TM could replicate in MT-2, MT-4, TALL-1 and MOLT-4 cells. The KB-1 strain is a useful HIV-1 isolate for investigating the function of the cytoplasmic domain of the TM and the significance of the presence of an in-frame stop codon in HIV env gene.