Nitric oxide inhibits the HIV-1 reverse transcriptase activity.

Nitric oxide (NO) is a polypotent regulatory molecule involved in a variety of activities, such as the modulation of the catalytic activity of cysteine-containing enzymes. The present study reports the modulation of the HIV-1 reverse transcriptase activity by NO, released by the NO-donors 3, 3-bis(aminoethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18), (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR-3), 3-morpholinosydnonimine (SIN-1), 4-(phenylsulfonyl)-3-((2-(dimethylamino) ethyl)thio)furoxan oxalate (SNO-102), and sodium nitroprusside (SNP). NO inhibits dose-dependently the HIV-1 reverse transcriptase activity, likely due to oxidation of Cys residue(s). Present results, representing a new insight into the modulation mechanism of the HIV-1 reverse transcriptase activity, may be relevant to develop new strategies for inhibition of HIV-1 replication.