The in vitro ejection of zinc from human immunodeficiency virus (HIV) type 1 nucleocapsid protein by disulfide benzamides with cellular anti-HIV activity.
Several disulfide benzamides have been shown to possess wide-spectrum antiretroviral activity in cell culture at low micromolar to submicromolar concentrations, inhibiting human immunodeficiency virus (HIV) type 1 (HIV-1) clinical and drug-resistant strains along with HIV-2 and simian immunodeficiency virus [Rice, W. G., Supko, J. G., Malspeis, L., Buckheit, R. W., Jr., Clanton, D., Bu, M., Graham, L., Schaeffer, C. A., Turpin, J. A., Domagala, J., Gogliotti, R., Bader, J. P., Halliday, S. M., Coren, L., Sowder, R. C., II, Arthur, L. O. & Henderson, L. E. (1995) Science 270, 1194-1197]. Rice and coworkers have proposed that the compounds act by "attacking" the two zinc fingers of HIV nucleocapsid protein. Shown here is evidence that low micromolar concentrations of the anti-HIV disulfide benzamides eject zinc from HIV nucleocapsid protein (NCp7) in vitro, as monitored by the zinc-specific fluorescent probe N-(6-methoxy-8-quinoyl)-p-toluenesulfonamide (TSQ). Structurally similar disulfide benzamides that do not inhibit HIV-1 in culture do not eject zinc, nor do analogs of the antiviral compounds with the disulfide replaced with a methylene sulfide. The kinetics of NCp7 zinc ejection by disulfide benzamides were found to be nonsaturable and biexponential, with the rate of ejection from the C-terminal zinc finger 7-fold faster than that from the N-terminal. The antiviral compounds were found to inhibit the zinc-dependent binding of NCp7 to HIV psi RNA, as studied by gel-shift assays, and the data correlated well with the zinc ejection data. Anti-HIV disulfide benzamides specifically eject NCp7 zinc and abolish the protein's ability to bind psi RNA in vitro, providing evidence for a possible antiretroviral mechanism of action of these compounds. Congeners of this class are under advanced preclinical evaluation as a potential chemotherapy for acquired immunodeficiency syndrome.
Tummino
P J
PJ
Department of Biochemistry, Parke-Davis Pharmaceutical Research, Division of Warner Lambert Co., Ann Arbor, MI 48105, USA.
Scholten
J D
JD
Harvey
P J
PJ
Holler
T P
TP
Maloney
L
L
Gogliotti
R
R
Domagala
J
J
Hupe
D
D
D000595:Amino Acid Sequence; D000634:Aminoquinolines; D000998:Antiviral Agents / Q000494:pharmacology*; D001549:Benzamides / Q000494:pharmacology*; D002213:Capsid / Q000187:drug effects / Q000378:metabolism*; D003001:Cloning, Molecular; D004220:Disulfides / Q000494:pharmacology*; D005456:Fluorescent Dyes; D015497:HIV-1 / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D013329:Structure-Activity Relationship; D014105:Tosyl Compounds; D014364:Tryptophan; D014758:Viral Core Proteins / Q000187:drug effects / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D000634:Aminoquinolines; D000998:Antiviral Agents; D001549:Benzamides; D004220:Disulfides; D005456:Fluorescent Dyes; C098073:PD 156202; D011994:Recombinant Proteins; D014105:Tosyl Compounds; D014758:Viral Core Proteins; C061730:N-(6-methoxy-8-quinolyl)-4-toluenesulfonamide; D014364:Tryptophan; D015032:Zinc