Structures of Chloroquine Resistance Transporter (PfCRT) Isoforms and Their Interactions with Chloroquine.

Biochemistry

Departments of Chemistry and Biochemistry and Cellular and Molecular Biology, Georgetown University, 37th and O Streets NW, Washington, District of Columbia 20057, United States.

Published: March 2023


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Article Abstract

Using a recently elucidated atomic-resolution cryogenic electron microscopy (cryo-EM) structure for the chloroquine resistance transporter (PfCRT) protein 7G8 isoform as template [Kim, J.; 2019, 576, 315-320], we use Monte Carlo molecular dynamics (MC/MD) simulations of PfCRT embedded in a 1-palmitoyl-2-oleoyl--glycero-3-phosphocholine (POPC) membrane to solve energy-minimized structures for 7G8 PfCRT and two additional PfCRT isoforms that harbor 5 or 7 amino acid substitutions relative to 7G8 PfCRT. Guided by drug binding previously defined using chloroquine (CQ) photoaffinity probe labeling, we also use MC/MD energy minimization to elucidate likely CQ binding geometries for the three membrane-embedded isoforms. We inventory salt bridges and hydrogen bonds in these structures and summarize how the limited changes in primary sequence subtly perturb local PfCRT isoform structure. In addition, we use the "AlphaFold" artificial intelligence AlphaFold2 (AF2) algorithm to solve for domain structure that was not resolved in the previously reported 7G8 PfCRT cryo-EM structure, and perform MC/MD energy minimization for the membrane-embedded AF2 structures of all three PfCRT isoforms. We compare energy-minimized structures generated using cryo-EM vs AF2 templates. The results suggest how amino acid substitutions in drug resistance-associated isoforms of PfCRT influence PfCRT structure and CQ transport.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10950298PMC
http://dx.doi.org/10.1021/acs.biochem.2c00669DOI Listing

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Structures of Chloroquine Resistance Transporter (PfCRT) Isoforms and Their Interactions with Chloroquine.

Biochemistry

March 2023

Departments of Chemistry and Biochemistry and Cellular and Molecular Biology, Georgetown University, 37th and O Streets NW, Washington, District of Columbia 20057, United States.

Using a recently elucidated atomic-resolution cryogenic electron microscopy (cryo-EM) structure for the chloroquine resistance transporter (PfCRT) protein 7G8 isoform as template [Kim, J.; 2019, 576, 315-320], we use Monte Carlo molecular dynamics (MC/MD) simulations of PfCRT embedded in a 1-palmitoyl-2-oleoyl--glycero-3-phosphocholine (POPC) membrane to solve energy-minimized structures for 7G8 PfCRT and two additional PfCRT isoforms that harbor 5 or 7 amino acid substitutions relative to 7G8 PfCRT. Guided by drug binding previously defined using chloroquine (CQ) photoaffinity probe labeling, we also use MC/MD energy minimization to elucidate likely CQ binding geometries for the three membrane-embedded isoforms.

View Article and Find Full Text PDF