HIV encodes an effective inhibitor peptide of integrase (IN), a peptide composed of six amino acids, which is responsible for integrating HIV DNA into the human genome. HIV Integrate Protein Inhibitor can inhibit IN mediated 3 'processing and integration, with an IC of 2 µ M. This peptide also has activity against IN proteins from other retroviruses such as HIV-2, feline immunodeficiency virus, and Moroni mouse leukemia virus. It was also found that it can inhibit the decomposition reaction, indicating that this hexapeptide acts at or near the catalytic site of IN.