INHIBITION OF THE HUMAN IMMUNODEFICIENCY VIRUS-1 PROTEASE AND HUMAN IMMUNODEFICIENCY VIRUS-1 REPLICATION BY BATHOCUPROINE DISULFONIC ACID CU1+

The protease encoded by the human immunodeficiency virus-1 (HIV-1) is essential for processing viral polyproteins which contain the enzymes and structural proteins required for the infectious virus. It was prev iously found that cupric chloride, in the presence of dithiothreitol o r ascorbic acid, could inhibit the HIV-1 protease. It was suggested th at a Cu1+ chelate was the moiety responsible for inhibition of the pro tease. This hypothesis has now been investigated directly by utilizing the stable Cu1+ chelate, bathocuproine disulfonic acid Cu1+ (BCDS-Cu1 +). BCDS-Cu1+ inhibited the HIV-1 wild type protease as well as a muta nt HIV-1 protease lacking cysteines, BCDS-Cu1+ was a competitive inhib itor of the mutant HIV-1 protease with an apparent K-i of 1 mu M. Repl ication of HIV-1 in human lymphocytes and the cytotoxic effect of HIV- 1 in CEM cells was inhibited by micromolar BCDS-Cu1+. Inhibition of th e protease and of HIV replication by BCDS-Cu1+ was dependent on the pr esence of Cu1+ as BCDS alone was ineffective. EDTA blocked the inhibit ion of the protease by Cu1+ but was unable to block inhibition of the protease by BCDS-Cu1+, indicating that the Cu1+ complex was the inhibi tory agent. The apparent IC50 for BCDS-Cu1+ on the inhibition of repli cation by primary isolates of HIV-1 was 5 mu M. However, BCDS-Cu1+ did not affect polyprotein processing in an H9 cell line chronically infe cted with HIV-1, indicating that BCDS-Cu1+ acts by yet another mechani sm to block HIV infection. Other possible targets for BCDSCu1+ include inhibition of viral adsorption and/or inhibition of the HIV-1 integra se.