A solid phase assay for the protease of human immunodeficiency virus

A solid phase assay for human immunodeficiency virus (HIV) protease using an immobilized substrate, Affi Gel 10-Gly-Gly-Gly-Gly-Val-Ser-Gln-Asn-Tyr-Pro-Ile-Val-Gln-[3H]Gly-OH has been devised. The Tyr-Pro bond of the substrate was hydrolyzed by the protease, releasing the radiolabeled cleavage product, Pro-Ile-Val-Gln-[3H]Gly-OH, into the supernatant. The pH optimum was found to be 6.0, and a high ionic strength was required for maximal activity. The solid phase assay is usable for convenient monitoring of purification procedures, and rapid screening of inhibitors of HIV protease.