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Medicine and Health Sciences

Selected Works

Celia A. Schiffer

Gene Products, gag

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Co-Evolution Of Nelfinavir-Resistant Hiv-1 Protease And The P1-P6 Substrate, Madhavi Kolli, Stephane Lastere, Celia Schiffer Nov 2011

Co-Evolution Of Nelfinavir-Resistant Hiv-1 Protease And The P1-P6 Substrate, Madhavi Kolli, Stephane Lastere, Celia Schiffer

Celia A. Schiffer

The selective pressure of the competitive protease inhibitors causes both HIV-1 protease and occasionally its substrates to evolve drug resistance. We hypothesize that this occurs particularly in substrates that protrude beyond the substrate envelope and contact residues that mutate in response to a particular protease inhibitor. To validate this hypothesis, we analyzed substrate and protease sequences for covariation. Using the chi2 test, we show a positive correlation between the nelfinavir-resistant D30N/N88D protease mutations and mutations at the p1-p6 cleavage site as compared to the other cleavage sites. Both nelfinavir and the substrate p1-p6 protrude beyond the substrate envelope and contact …


Mechanism Of Substrate Recognition By Drug-Resistant Human Immunodeficiency Virus Type 1 Protease Variants Revealed By A Novel Structural Intermediate, Moses Prabu-Jeyabalan, Ellen A. Nalivaika, Keith Romano, Celia A. Schiffer Nov 2011

Mechanism Of Substrate Recognition By Drug-Resistant Human Immunodeficiency Virus Type 1 Protease Variants Revealed By A Novel Structural Intermediate, Moses Prabu-Jeyabalan, Ellen A. Nalivaika, Keith Romano, Celia A. Schiffer

Celia A. Schiffer

Human immunodeficiency virus type 1 (HIV-1) protease processes and cleaves the Gag and Gag-Pol polyproteins, allowing viral maturation, and therefore is an important target for antiviral therapy. Ligand binding occurs when the flaps open, allowing access to the active site. This flexibility in flap geometry makes trapping and crystallizing structural intermediates in substrate binding challenging. In this study, we report two crystal structures of two HIV-1 protease variants bound with their corresponding nucleocapsid-p1 variant. One of the flaps in each of these structures exhibits an unusual "intermediate" conformation. Analysis of the flap-intermediate and flap-closed crystal structures reveals that the intermonomer …