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001-es BibID:	BIBFORM086386
Első szerző:	Liu, Fengling
Cím:	Analysis of HIV-1 protease mutants to understand mechanisms of resistance / Liu F., Boross Péter, Tőzsér József, Louis J. M., Harrison R. W., Weber I. T.
Dátum:	2005
ISSN:	1742-464X
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idézhető absztrakt folyóiratcikk
Megjelenés:	Febs Journal. - 272 : Suppl1 (2005), p. 12. -
További szerzők:	Boross Péter (1972-) (biokémikus, vegyész) Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész) Louis, John M. Harrison, Robert W. Weber, Irene T.
Pályázati támogatás:	OTKA T43482 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM040663
Első szerző:	Liu, Fengling
Cím:	Kinetic, Stability, and Structural Changes in High-resolution Crystal Structures of HIV-1 Protease with Drug-resistant Mutations L24I, I50V, and G73S / Liu Fengling, Boross Peter I., Wang Yuan-Fang, Tozser Jozsef, Louis John M., Harrison Robert W., Weber Irene T.
Dátum:	2005
ISSN:	0022-2836
Megjegyzések:	The crystal structures, dimer stabilities, and kinetics have been analyzed for wild-type human immunodeficiency virus type 1 (HIV-1) protease (PR) and resistant mutants PR(L24I), PR(I50V), and PR(G73S) to gain insight into the molecular basis of drug resistance. The mutations lie in different structural regions. Mutation I50V alters a residue in the flexible flap that interacts with the inhibitor, L24I alters a residue adjacent to the catalytic Asp25, and G73S lies at the protein surface far from the inhibitor-binding site. PR(L24I) and PR(I50V), showed a 4% and 18% lower k(cat)/K(m), respectively, relative to PR. The relative k(cat)/K(m) of PR(G73S) varied from 14% to 400% when assayed using different substrates. Inhibition constants (K(i)) of the antiviral drug indinavir for the reaction catalyzed by the mutant enzymes were about threefold and 50-fold higher for PR(L24I) and PR(I50V), respectively, relative to PR and PR(G73S). The dimer dissociation constant (K(d)) was estimated to be approximately 20 nM for both PR(L24I) and PR(I50V), and below 5 nM for PR(G73S) and PR. Crystal structures of the mutants PR(L24I), PR(I50V) and PR(G73S) were determined in complexes with indinavir, or the p2/NC substrate analog at resolutions of 1.10-1.50 Angstrom. Each mutant revealed distinct structural changes relative to PR. The mutated residues in PR(L24I) and PR(I50V) had reduced intersubunit contacts, consistent with the increased K(d) for dimer dissociation. Relative to PR, PR(I50V) had fewer interactions of Val50 with inhibitors, in agreement with the dramatically increased K(i). The distal mutation G73S introduced new hydrogen bond interactions that can transmit changes to the substrate-binding site and alter catalytic activity. Therefore, the structural alterations observed for drug-resistant mutations were in agreement with kinetic and stability changes.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Molecular Biology. - 354 : 4 (2005), p. 789-800. -
További szerzők:	Boross Péter (1972-) (biokémikus, vegyész) Wang, Yuan-Fang Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész) Louis, John M. Harrison, Robert W. Weber, Irene T.
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM040678
Első szerző:	Tie, Yunfeng
Cím:	Molecular basis for substrate recognition and drug resistance from 1.1 to 1.6 A angstroms resolution crystal structures of HIV-1 protease mutants with substrate analogs / Tie Yunfeng, Boross Peter I., Wang Yuan-Fang, Gaddis Laquasha, Liu Fengling, Chen Xianfeng, Tozser Jozsef, Harrison Robert W., Weber Irene T.
Dátum:	2005
ISSN:	1742-464X
Megjegyzések:	HIV-1 protease (PR) and two drug-resistant variants--PR with the V82A mutation (PR(V82A)) and PR with the I84V mutation (PR(I84V))--were studied using reduced peptide analogs of five natural cleavage sites (CA-p2, p2-NC, p6pol-PR, p1-p6 and NC-p1) to understand the structural and kinetic changes. The common drug-resistant mutations V82A and I84V alter residues forming the substrate-binding site. Eight crystal structures were refined at resolutions of 1.10-1.60 A. Differences in the PR-analog interactions depended on the peptide sequence and were consistent with the relative inhibition. Analog p6(pol)-PR formed more hydrogen bonds of P2 Asn with PR and fewer van der Waals contacts at P1' Pro compared with those formed by CA-p2 or p2-NC in PR complexes. The P3 Gly in p1-p6 provided fewer van der Waals contacts and hydrogen bonds at P2-P3 and more water-mediated interactions. PR(I84V) showed reduced van der Waals interactions with inhibitor compared with PR, which was consistent with kinetic data. The structures suggest that the binding affinity for mutants is modulated by the conformational flexibility of the substrate analogs. The complexes of PR(V82A) showed smaller shifts of the main chain atoms of Ala82 relative to PR, but more movement of the peptide analog, compared to complexes with clinical inhibitors. PR(V82A) was able to compensate for the loss of interaction with inhibitor caused by mutation, in agreement with kinetic data, but substrate analogs have more flexibility than the drugs to accommodate the structural changes caused by mutation. Hence, these structures help to explain how HIV can develop drug resistance while retaining the ability of PR to hydrolyze natural substrates.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Febs Journal. - 272 : 20 (2005), p. 5265-5277. -
További szerzők:	Boross Péter (1972-) (biokémikus, vegyész) Wang, Yuan-Fang Gaddis, Laquasha Liu, Fengling Chen, Xianfeng Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész) Harrison, Robert W. Weber, Irene T.
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