TI: Ozone May Inactivate HIV by Reducing gp120-CD4 Binding Affinity, Lysing the HIV Lipid Envelope, and Oxidizing the HIV Core DT: Late 1993 AU: Oscar K.H. Hsu SO: Department of Biochemistry, Molecular, Cellular, and Developmental Biology, Harvard University, Cambridge, MA AB: In vitro studies have demonstrated that the ozonation of human blood inactivates HIV. This paper describes a biochemical framework whereby ozone may inactivate HIV by attacking solvent accessible amino acids in the gp120 and ply-unsaturated fatty acids in the virus' lipid envelope. Ozone may reduce gp120-CD4 binding affinity by converting gp120's Trp-427 into kynurenine and dehydroxylating Tyr-435. These two amino acids form gp120's hydrophobic receptor for the CD4 Phe-43 ligand; oxidation of these two solvent- accessible amino acids probably alters the conformation of gp120's hydrophobic receptor substantially. Additionally, disruption of HIV membrane integrity by the ozone-lipid reaction products, hydrogen peroxide and lipid-derived aldehydes, could result in the oxidation of the HIV core by a host of pathways. This cascade of events, initiated by ozone, provides a plausible biochemical framework for the inactivation of HIV in human blood.