Interface of Evolution and Structure Based Drug Design

Our Lab

Constraining evolution and avoiding drug resistance

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Drug resistance occurs when, through evolution, a disease no longer responds to medications. Resistance impacts the lives of millions, limiting the effectiveness of many of our most potent drugs. This often happens under the selective pressure of therapy in bacterial, viral and fungal infections and cancer due to their rapid evolution.

We combine a variety of experimental and computational techniques to understand the molecular basis of drug resistance. Our new paradigm of drug design minimizes chances of resistance. Realizing that disrupting the drug target’s activity is necessary but not sufficient for developing a robust drug that avoids resistance.

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Research Focus

Strategies and Systems

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We use multidisciplinary approaches, combining crystallography, enzymology, molecular dynamics and organic chemistry, to elucidate the molecular mechanisms of drug resistance. Resistance occurs when a heterogeneous populations of a drug target is challenged by the selective pressure of a drug. In cancer and viruses this heterogeneity is partially caused APOBEC3’s. We discovered resistance mutations occur either where drugs physically contact regions of the drug target that are not essential for substrate recognition or alter the ensemble dynamics of the drug target favoring substrate. We leverage these insights into a new strategies in structure-based drug design to minimize the likelihood for resistance by designing inhibitors to stay within the substrate envelope. This strategy not only describes most of the primary drug resistance for HIV, Hepatitis C viral protease inhibitors and influenza neuraminidase, but is generally applicable in the development of novel drugs that are less susceptible to resistance.

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Publications

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Total: 1 results
  • HIV-1 Protease Uses Bi-Specific S2/S2' Subsites to Optimize Cleavage of Two Classes of Target Sites.

    Author(s): Potempa M, Lee SK, KurtYilmaz N, Nalivaika EA, Rogers A, Spielvogel E, Carter CW, Schiffer CA, Swanstrom R
    Related Articles

    HIV-1 Protease Uses Bi-Specific S2/S2' Subsites to Optimize Cleavage of Two Classes of Target Sites.

    J Mol Biol. 2018 Nov 07;:

    Authors: Potempa M, Lee SK, KurtYilmaz N, Nalivaika EA, Rogers A, Spielvogel E, Carter CW, Schiffer CA, Swanstrom R

    Abstract
    Retroviral proteases (PR) have a unique specificity that allows cleavage of sites with or without a P1' proline. A P1' proline is required at the MA/CA cleavage site due to its role in a post-cleavage conformational change in the capsid protein. However, the HIV-1 PR prefers to have large hydrophobic amino acids flanking the scissile bond, suggesting PR recognizes two different classes of substrate sequences. We analyzed the cleavage rate of over 150 combinations of six different HIV-1 cleavage sites to explore rate determinants of cleavage. We found that cleavage rates are strongly influenced by the two amino acids flanking the amino acids at the scissile bond (P2-P1/P1'-P2'), with two complementary sets of rules. When P1' is proline, the P2 side chain interacts with a polar region in the S2 subsite of the PR, while the P2' amino acid interacts with a hydrophobic region of the S2' subsite. When P1' is not proline, the orientations of the P2 and P2' side chains with respect to the scissile bond are reversed; P2 residues interact with a hydrophobic face of the S2 subsite while the P2' amino acid usually engages hydrophilic amino acids in the S2' subsite. These results reveal that the HIV-1 PR has evolved bi-functional S2 and S2' subsites to accommodate the steric effects imposed by a P1' proline on the orientation of P2 and P2' substrate side chains. These results also suggest a new strategy for inhibitor design to engage the multiple specificities in these subsites.

    PMID: 30414407 [PubMed - as supplied by publisher]

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Contact Us

Office:
Lazare Research Building 828
Campus Map (pdf)

Phone:
508-856-8008 (office)

Email:
Celia.Schiffer@umassmed.edu

Mailing Address:
University of Massachusetts Medical School
Attn: Dr. Celia Schiffer/BMP department
364 Plantation St LRB828
Worcester, MA 01605

Join Us

We are always interested in applications from qualified candidates at postdoctoral and research associate levels.

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Undergraduates interested in pursuing a PhD at UMass Medical School should apply directly to the Graduate School of Biomedical Sciences Program.