The discovery, characterization and crystallographically determined binding mode of an FMOC-containing inhibitor of HIV-1 protease.
A pharmacophore derived from the structure of the dithiolane derivative of haloperidol bound in the active site of the HIV-1 protease (HIV-1 PR) has been used to search a three-dimensional database for new inhibitory frameworks. This search identified an FMOC-protected N-tosyl arginine as a lead candidate. A derivative in which the arginine carboxyl has been converted to an amide has been crystallized with HIV-1 PR and the structure has been determined to a resolution of 2.5 A with a final R-factor of 18.5%. The inhibitor binds in an extended conformation that results in occupancy of the S2, S1', and S3' subsites of the active site. Initial structure-activity studies indicate that: (1) the FMOC fluorenyl moiety interacts closely with active site residues and is important for binding; (2) the N(G)-tosyl group is necessary to suppress protonation of the arginine guanidinyl terminus; and (3) the arginine carboxamide function is involved in interactions with the water coordinated to the catalytic aspartyl groups. FMOC-protected arginine derivatives, which appear to be relatively specific and nontoxic, offer promise for the development of useful HIV-1 protease inhibitors.
Rutenber
E E
EE
Department of Biochemistry and Biophysics, University of California at San Francisco, 94143, U.S.A.
De Voss
J J
JJ
Hoffman
L
L
Stroud
R M
RM
Lee
K H
KH
Alvarez
J
J
McPhee
F
F
Craik
C
C
Ortiz de Montellano
P R
PR
D000596:Amino Acids / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives* / Q000737:chemistry; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005449:Fluorenes / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D016333:HIV Protease / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D017320:HIV Protease Inhibitors / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D006220:Haloperidol / Q000031:analogs & derivatives; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D000596:Amino Acids; D005449:Fluorenes; D017320:HIV Protease Inhibitors; C108654:N(alpha)-FMOC-N(omega)-tosylarginine; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D001120:Arginine; D016333:HIV Protease; D006220:Haloperidol