Structure at 2.5-A resolution of chemically synthesized human immunodeficiency virus type 1 protease complexed with a hydroxyethylene-based inhibitor.Jaskolski, M., Tomasselli, A.G., Sawyer, T.K., Staples, D.G., Heinrikson, R.L., Schneider, J., Kent, S.B., Wlodawer, A.
(1991) Biochemistry 30: 1600-1609
- PubMed: 1993177
- PubMed Abstract:
- Enzymatic Activity of a Synthetic 99 Residue Protein Corresponding to the Putative HIV-1 Protease
Schneider, J.,Kent, S.B.H.
(1988) Cell 54: 363
- Conserved Folding in Retroviral Proteases. Crystal Structure of a Synthetic HIV-1 Protease
Wlodawer, A.,Miller, M.,Jaskolski, M.,Sathyanarayana, B.K.,Baldwin, E.,Weber, I.T.,Selk, L.M.,Clawson, L.,Schneider, J.,Kent, S.B.H.
(1989) Science 245: 616
- Molecular Modeling of the HIV-1 Protease and its Substrate Binding Site
Weber, I.T.,Miller, M.,Jaskolski, M.,Leis, J.,Skalka, A.M.,Wlodawer, A.
(1989) Science 243: 928
- Crystal Structure of a Retroviral Protease Proves Relationship to Aspartic Protease Family
Miller, M.,Jaskolski, M.,Rao, J.K.M.,Leis, J.,Wlodawer, A.
(1989) Nature 337: 576
The crystal structure of a complex between chemically synthesized human immunodeficiency virus type 1 (HIV-1) protease and an octapeptide inhibitor has been refined to an R factor of 0.138 at 2.5-A resolution. The substrate-based inhibitor, H-Val-Ser ...
The crystal structure of a complex between chemically synthesized human immunodeficiency virus type 1 (HIV-1) protease and an octapeptide inhibitor has been refined to an R factor of 0.138 at 2.5-A resolution. The substrate-based inhibitor, H-Val-Ser-Gln-Asn-Leu psi [CH(OH)CH2]Val-Ile-Val-OH (U-85548e) contains a hydroxyethylene isostere replacement at the scissile bond that is believed to mimic the tetrahedral transition state of the proteolytic reaction. This potent inhibitor has Ki less than 1 nM and was developed as an active-site titrant of the HIV-1 protease. The inhibitor binds in an extended conformation and is involved in beta-sheet interactions with the active-site floor and flaps of the enzyme, which form the substrate/inhibitor cavity. The inhibitor diastereomer has the S configuration at the chiral carbon atom of the hydroxyethylene insert, and the hydroxyl group is within H-bonding distance of the two active-site carboxyl groups in the enzyme dimer. The two subunits of the enzyme are related by a pseudodyad, which superposes them at a 178 degrees rotation. The main difference between the subunits is in the beta turns of the flaps, which have different conformations in the two monomers. The inhibitor has a clear preferred orientation in the active site and the alternative conformation, if any, is a minor one (occupancy of less than 30%). A new model of the enzymatic mechanism is proposed in which the proteolytic reaction is viewed as a one-step process during which the nucleophile (water molecule) and electrophile (an acidic proton) attack the scissile bond in a concerted manner.
Macromolecular Structure Laboratory, National Cancer Institute-Frederick Cancer Research and Development Center, Maryland 21702-1201.