EXPRESSION AND PURIFICATION OF GLUTATHIONE S-TRANSFERASE-TAGGED HIV-1 GP120 - NO EVIDENCE OF AN INTERACTION WITH CD26

We describe the use of a new baculovirus expression Vector to enable the secretion of the major surface glycoprotein of HIV-1 (gp120) fused to the carboxy-terminus of the widely used affinity tag glutathione S-transferase. The secreted protein can be purified in a single step with the minimum of denaturation on immobilised glutathione and is as active as the parental molecule in binding CD4. We use this molecule in a variety of assay formats to examine the gp120 interaction with CD26, a reported auxiliary molecule in the HIV entry process. We find no evidence of a CD26-gp120 interaction in the absence or presence of CD4. (C) 1995 Academic Press, Inc.