3rd Conf Retro and Opportun Infect. 1996 Jan 28-Feb 1;:178. Unique
Nucleocapsid (NC) proteins of retroviruses contain sequences of 14 amino
acids with 4 invariant residues, Cys(X)2Cys(X)4His(X)4Cys(CCHC), that
chelate zinc through histidine imidazole and cysteine thiolates(K(d)less
than 10(3)). The CCHC motif is one of the most highly conserved features
in retroviruses and is necessary to package genomic RNA into the virus.
Mutants with altered zinc-chelating residues (CCCC and CCHH) package
genomic RNA but are still noninfectious; thus the CCHC motif is
essential for early infection event(s). This apparent immutability of
the CCHC finger makes this structure an ideal drug target. We find that
the conserved cysteine thiolates (S*) in the finger can be destroyed by
electrophilic reagents and retrovirus particles are inactivated by
exposure to the reagents. We have developed a screening pathway which
begins with identification of lead compounds based on structure and
functional groups and extends to demonstration of activity on purified
NC protein, reaction with zinc fingers in the intact virus, anti-viral
activity in tissue culture, anti-viral activity in a SFFV/murine model
and anti-viral activity in SIV-infected macaques. Results of this drug
evaluation screen will be discussed.
Antiviral Agents/CHEMICAL SYNTHESIS/*PHARMACOLOGY Capsid/METABOLISM
Chelating Agents HIV-1/*DRUG EFFECTS/GENETICS/METABOLISM Human
Structure-Activity Relationship *Zinc Fingers ABSTRACT