Current Lab Members

Celia_Schiffer Celia A. Schiffer, PhD - Principle Investigator   
  /PageFiles/47768/MohanSomasundaran.png Mohan Somasundaran, PhD - Associate Professor

Akbar Ali, PhD - Research Associate Professor

My research is devoted to the discovery and development of small molecule therapeutics against drug-resistant pathogens. Under the auspices of Prof. Celia Schiffer, I lead medicinal chemistry efforts in several research projects, involving structure-guided design, chemical synthesis, and structure-activity relationship (SAR) studies of small-molecule inhibitors targeting viral enzymes (HIV-1 protease, HCV NS3/4A protease) and host-virus interactions (Vif-APOBEC).

 /PageFiles/47768/NeseKurtYilmaz.png Nese Kurt Yilmaz, PhD - Research Assistant Professor  
  Ellen_Nalivaika Ellen Nalivaika - Senior Research Associate  
  Brendan Hilbert, PhD - Postdoctoral Associate  
Madhavi_Kolli Madhavi Kolli, PhD - Postdoctoral associate

I study the co-evolution of HIV-1 Protease and it’s substrates. Protease resistance mutations that alter inhibitor binding can sometimes also affect substrate binding. Drug-resistant mutations in the protease, especially those in the active site, can compromise both specificity and catalytic capability of the protease, which in turn may exert a selective pressure on the cleavage sites leading to compensatory substitutions. I have analyzed viral sequences from infected patients for mutations within the substrate cleavage sites and their correlation to resistance-associated protease mutations and for the first time observed several instances of substrate co-evolution. Structural studies of the protease-substrate complexes show changes in hydrogen bonds, van der Waal interactions and conformational changes that likely alter catalytic efficiency of the protease. In addition I am also studying how these correlated mutations affect Gag processing and thus, resistance/fitness.


Ayşegül Özen, PhD - Postdoctoral Associate

Understanding substrate recognition, enzyme-substrate co-evolution and drug resistance in HIV-1 aspartyl and HCV NS3/4A serine proteases using x-ray crystallography, molecular modeling, and dynamics simulations.

Incoporating the dynamic substrate envelope into the design of new drugs targeting ensembles of drug-resistant proteases.

  Janet Paulsen, PhD - Postdoctoral Associate  
  Shivender Shandilya, PhD - Postdoctoral associate  
Markus-Fredrick_Bohn Markus-Frederik Bohn, M.Sc. - Visiting PhD student, Nuremberg, Germany

APOBEC3A is an extremely potent DNA mutator that has been shown to involve in degradation of foreign DNA in phagocytic cells and cancer development. AID and/or APOBEC3F/A may also play a significant role in epigenetic reprogramming. Our focus lies on establishing APOBEC3 proteins as host-encoded molecular targets for antiviral strategies by using a structural and biochemical approach.

  Brendan Hilbert, PhD - Postdoctoral Associate  
Kuan-Hung_Lin Kuan-Hung Lin - PhD student  
 Kristina_Prachanronarong Kristina Prachanronarong - MD/PhD student  
  Debra Ann Ragland - PhD student  
  Tania Silvas - PhD student  
Djade_Soumana Djade Soumana - PhD student

I earned my BS in Biochemistry and Molecular Biology from the University of Massachusetts at Amherst. Currently, I'm a PhD candidate in the Biochemistry and Pharmacology Department here at UMass, where I'm studying the atomic basis for drug resistance in Hepatitis C. With a combinatorial use of structural biology and enzyme kinetics, I'm interested in investigating how of mutations in the HCV NS3 protease confers drug resistance.

  Candice Dufour - Administrative Assistant