Abstract
Human carbonic anhydrases (hCAs) play various roles in cells, and have been drug targets for decades. Sequence similarities of hCA isoforms necessitate designing specific inhibitors, which requires detailed structural information for hCA-inhibitor complexes. We present room temperature neutron structures of hCA II in complex with three clinical drugs that provide in-depth analysis of drug binding, including protonation states of the inhibitors, hydration water structure, and direct visualization of hydrogen-bonding networks in the enzyme's active site. All sulfonamide inhibitors studied bind to the Zn metal center in the deprotonated, anionic, form. Other chemical groups of the drugs can remain neutral or be protonated when bound to hCA II. MD simulations have shown that flexible functional groups of the inhibitors may alter their conformations at room temperature and occupy different sub-sites. This study offers insights into the design of specific drugs to target cancer-related hCA isoform IX. Kovalevsky et al. used macromolecular neutron crystallography and molecular dynamics simulations to obtain a detailed picture of clinical inhibitors binding to human carbonic anhydrase II. The study visualized hydrogen atom positions, revealing protonation/deprotonation events and intricate hydrogen-bonding networks, providing insights for drug design.
Original language | English |
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Pages (from-to) | 383-390.e3 |
Journal | Structure |
Volume | 26 |
Issue number | 3 |
DOIs | |
State | Published - Mar 6 2018 |
Funding
This work has been funded by a Shull Fellowship awarded to M.A. at Oak Ridge National Laboratory (ORNL). This research at ORNL's Spallation Neutron Source (MaNDi beamline) and the Shull Fellowship were sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy (DOE-BES). The Office of Biological and Environmental Research supported research at ORNL's Center for Structural Molecular Biology involving protein deuteration, using facilities supported by the Scientific User Facilities Division (DOE-BES). The authors thank Institut Laue Langevin (beamline LADI-III) for awarded neutron beamtime. This manuscript has been authored by UT-Battelle LLC under DOE Contract No. DE-AC05-00OR22725. This work has been funded by a Shull Fellowship awarded to M.A. at Oak Ridge National Laboratory (ORNL). This research at ORNL's Spallation Neutron Source (MaNDi beamline) and the Shull Fellowship were sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy (DOE-BES). The Office of Biological and Environmental Research supported research at ORNL's Center for Structural Molecular Biology involving protein deuteration, using facilities supported by the Scientific User Facilities Division (DOE-BES). The authors thank Institut Laue Langevin (beamline LADI-III) for awarded neutron beamtime. This manuscript has been authored by UT-Battelle LLC under DOE Contract No. DE-AC05-00OR22725.
Keywords
- MD simulations
- brinzolamide
- dorzolamide
- drug binding
- ethoxzolamide
- human carbonic anhydrase
- hydrogen bonding
- neutron crystallography
- perdeuteration