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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology
Context Surrounding Processing Sites Is Crucial In Determining Cleavage Rate Of A Subset Of Processing Sites In Hiv-1 Gag And Gag-Pro-Pol Polyprotein Precursors By Viral Protease, Sook-Kyung Lee, Marc Potempa, Madhavi Kolli, Aysegul Ozen, Celia Schiffer, Ronald Swanstrom
Context Surrounding Processing Sites Is Crucial In Determining Cleavage Rate Of A Subset Of Processing Sites In Hiv-1 Gag And Gag-Pro-Pol Polyprotein Precursors By Viral Protease, Sook-Kyung Lee, Marc Potempa, Madhavi Kolli, Aysegul Ozen, Celia Schiffer, Ronald Swanstrom
Celia A. Schiffer
Processing of the human immunodeficiency virus type 1 (HIV-1) Gag and Gag-Pro-Pol polyproteins by the HIV-1 protease (PR) is essential for the production of infectious particles. However, the determinants governing the rates of processing of these substrates are not clearly understood. We studied the effect of substrate context on processing by utilizing a novel protease assay in which a substrate containing HIV-1 matrix (MA) and the N-terminal domain of capsid (CA) is labeled with a FlAsH (fluorescein arsenical hairpin) reagent. When the seven cleavage sites within the Gag and Gag-Pro-Pol polyproteins were placed at the MA/CA site, the rates of …
Molecular Basis For Drug Resistance In Hiv-1 Protease, Akbar Ali, Rajintha M. Bandaranayake, Yufeng Cai, Nancy M. King, Madhavi Kolli, Seema Mittal, Jennifer E. Foulkes-Murzycki, Madhavi N. L. Nalam, Ellen A. Nalivaika, Aysegul Ozen, Moses Prabu-Jeyabalan, Kelly Thayer, Celia A. Schiffer
Molecular Basis For Drug Resistance In Hiv-1 Protease, Akbar Ali, Rajintha M. Bandaranayake, Yufeng Cai, Nancy M. King, Madhavi Kolli, Seema Mittal, Jennifer E. Foulkes-Murzycki, Madhavi N. L. Nalam, Ellen A. Nalivaika, Aysegul Ozen, Moses Prabu-Jeyabalan, Kelly Thayer, Celia A. Schiffer
Celia A. Schiffer
HIV-1 protease is one of the major antiviral targets in the treatment of patients infected with HIV-1. The nine FDA approved HIV-1 protease inhibitors were developed with extensive use of structure-based drug design, thus the atomic details of how the inhibitors bind are well characterized. From this structural understanding the molecular basis for drug resistance in HIV-1 protease can be elucidated. Selected mutations in response to therapy and diversity between clades in HIV-1 protease have altered the shape of the active site, potentially altered the dynamics and even altered the sequence of the cleavage sites in the Gag polyprotein. All …
Co-Evolution Of Nelfinavir-Resistant Hiv-1 Protease And The P1-P6 Substrate, Madhavi Kolli, Stephane Lastere, Celia Schiffer
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 …
Tmc310911, A Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, Shows In Vitro An Improved Resistance Profile And Higher Genetic Barrier To Resistance Compared With Current Protease Inhibitors, Inge Dierynck, Herwig Van Marck, Marcia Van Ginderen, Tim Jonckers, Madhavi Nalam, Celia Schiffer, Araz Raoof, Guenter Kraus, Gaston Picchio
Tmc310911, A Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, Shows In Vitro An Improved Resistance Profile And Higher Genetic Barrier To Resistance Compared With Current Protease Inhibitors, Inge Dierynck, Herwig Van Marck, Marcia Van Ginderen, Tim Jonckers, Madhavi Nalam, Celia Schiffer, Araz Raoof, Guenter Kraus, Gaston Picchio
Celia A. Schiffer
TMC310911 is a novel human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) structurally closely related to darunavir (DRV) but with improved virological characteristics. TMC310911 has potent activity against wild-type (WT) HIV-1 (median 50% effective concentration [EC(50)], 14 nM) and a wide spectrum of recombinant HIV-1 clinical isolates, including multiple-PI-resistant strains with decreased susceptibility to currently approved PIs (fold change [FC] in EC(50), >10). For a panel of 2,011 recombinant clinical isolates with decreased susceptibility to at least one of the currently approved PIs, the FC in TMC310911 EC(50) was
Replacement Of The P1 Amino Acid Of Human Immunodeficiency Virus Type 1 Gag Processing Sites Can Inhibit Or Enhance The Rate Of Cleavage By The Viral Protease, Steve Pettit, Gavin Henderson, Celia Schiffer, Ronald Swanstrom
Replacement Of The P1 Amino Acid Of Human Immunodeficiency Virus Type 1 Gag Processing Sites Can Inhibit Or Enhance The Rate Of Cleavage By The Viral Protease, Steve Pettit, Gavin Henderson, Celia Schiffer, Ronald Swanstrom
Celia A. Schiffer
Processing of the human immunodeficiency virus type 1 (HIV-1) Gag precursor is highly regulated, with differential rates of cleavage at the five major processing sites to give characteristic processing intermediates. We examined the role of the P1 amino acid in determining the rate of cleavage at each of these five sites by using libraries of mutants generated by site-directed mutagenesis. Between 12 and 17 substitution mutants were tested at each P1 position in Gag, using recombinant HIV-1 protease (PR) in an in vitro processing reaction of radiolabeled Gag substrate. There were three sites in Gag (MA/CA, CA/p2, NC/p1) where one …
Three Residues In Hiv-1 Matrix Contribute To Protease Inhibitor Susceptibility And Replication Capacity, Chris Parry, Madhavi Kolli, Richard Myers, Patricia Cane, Celia Schiffer, Deenan Pillay
Three Residues In Hiv-1 Matrix Contribute To Protease Inhibitor Susceptibility And Replication Capacity, Chris Parry, Madhavi Kolli, Richard Myers, Patricia Cane, Celia Schiffer, Deenan Pillay
Celia A. Schiffer
Other than cleavage site mutations, there is little data on specific positions within Gag that impact on HIV protease inhibitor susceptibility. We have recently shown that non-cleavage site mutations in gag, particularly within matrix protein can restore replication capacity and further reduce protease inhibitor drug susceptibility when coexpressed with a drug-resistant (mutant) protease. The matrix protein of this patient-derived virus was studied in order to identify specific changes responsible for this phenotype. Three amino acid changes in matrix (R76K, Y79F, and T81A) had an impact on replication capacity as well as drug susceptibility. Introduction of these three changes into wild-type …