Identification of HIV-1 nucleocapsid protein: nucleic acid antagonists with cellular anti-HIV activity.
The crucial functions of HIV-1 nucleocapsid-p7 protein (NC-p7) at different stages of HIV replication are dependent on its nucleic acid binding properties. In this study, a search has been made to identify antagonists of the interaction between NC-p7 and d(TG)(4). A chemical library of approximately 2000 small molecules (the NCI Diversity Set) was screened, of the 26 active inhibitors that were identified, five contained a xanthenyl ring structure. Further analysis of 63 structurally related compounds led to the identification of 2,3,4,5-tetrachloro-6-(4('),5('),6(')-trihydroxy-3(')-oxo-3H-xanthen-9(')-yl)benzoic acid, which binds to NC-p7 stoichiometrically. This compound exerted a significant anti-HIV activity in vitro with an IC(50) of 16.6+/-4.3 microM (means+/-SD). Synthetic variants lacking the two hydroxyls at positions 4(') and 5(') in the xanthenyl ring system failed to bind NC-p7 and showed significantly less protection against HIV infection. Molecular modeling predicts that these hydroxyl groups would bind to the amide nitrogen of Gly(35) with other contacts at the carbonyl oxygens of Gly(40) and Lys(33).
Stephen
Andrew G
AG
Protein Chemistry Laboratory, SAIC-Frederick, Inc., NCI Frederick, 21702, Frederick, MD, USA.
Worthy
Karen M
KM
Towler
Eric
E
Mikovits
Judy A
JA
Sei
Shizuko
S
Roberts
Paula
P
Yang
Quan-en
QE
Akee
Rhone K
RK
Klausmeyer
Paul
P
McCloud
Thomas G
TG
Henderson
Lou
L
Rein
Alan
A
Covell
David G
DG
Currens
Michael
M
Shoemaker
Robert H
RH
Fisher
Robert J
RJ
D019380:Anti-HIV Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D002213:Capsid / Q000037:antagonists & inhibitors* / Q000378:metabolism; D036022:Capsid Proteins; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004801:Eosine Yellowish-(YS) / Q000737:chemistry / Q000378:metabolism; D005452:Fluoresceins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015683:Gene Products, gag / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D009841:Oligonucleotides / Q000378:metabolism; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D014764:Viral Proteins; D014966:Xanthenes / Q000378:metabolism / Q000494:pharmacology; D054301:gag Gene Products, Human Immunodeficiency Virus
D019380:Anti-HIV Agents; D036022:Capsid Proteins; D005452:Fluoresceins; D015683:Gene Products, gag; C071884:NCP7 protein, Human immunodeficiency virus 1; D009841:Oligonucleotides; D014764:Viral Proteins; D014966:Xanthenes; D054301:gag Gene Products, Human Immunodeficiency Virus; C466630:tetrachlorogallein; C007820:gallein; D004801:Eosine Yellowish-(YS)