Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Novel fluorogenic substrates for human immunodeficiency viral protease have been developed based on the principle of fluorescence energy transfer. Starting from a p24/p15 cleavage site-derived hexapeptide substrate. Ac-Thr-Ile-Nle-Nle-Gln-Arg-NH2, incorporation of 2-aminobenzoic acid in place of the acetyl group as the donor and p-NO2-Phe at the P1' position as acceptor gave the intramolecularly quenched fluorogenic substrate. Cleavage of the substrate by HIV protease released the fluorescent N-terminal tripeptide from its close apposition to the quenching nitrobenzyl group, resulting in enhanced fluorescence. An automated assay based on 96-well microtiter plates and a fluorometric plate reader have been developed, which allow high throughput of compounds in the search for HIV protease inhibitors.
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PMID:A simple, continuous fluorometric assay for HIV protease. 209 Jun 47

A novel fluorogenic substrate for continuous feline immunodeficiency virus (FIV) protease (PR) assay was developed in which 2-aminobenzoic acid (Abz) and p-nitrophenylalanine (F(NO2)) were used as the fluorescent donor and acceptor, respectively. The 14-amino-acid fluorogenic substrate of sequence RALTK(Abz) VQ approximately F(NO2)VQSKGR (approximately indicates cleavage site) was modeled after a naturally occurring FIV PR capsid/nucleocapsid cleavage site in the gag polyprotein. The 2-aminobenzoyl group was attached to the epsilon amino group of a lysine (K(Abz)) in position P3 and the F(NO2) is in position P1' in order to promote efficient intramolecular quenching prior to cleavage by FIV PR. We measured a K(m) of 33 +/- 6 microM and a kcat of 0.29 +/- 0.02 s-1 for the enzymatic hydrolysis of this fluorogenic substrate by FIV PR under the conditions of our assay (0.05 M sodium citrate/0.1 M sodium phosphate buffer, pH 5.25, 0.2 M NaCl, 0.1 mM EDTA, and 1 mM dithiothreitol). This assay affords a rapid and convenient means for quantitating FIV PR activities and promises to be useful for judging the relative strength of inhibitors.
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PMID:A continuous fluorometric assay for the feline immunodeficiency virus protease. 941 81