Electric field measurements reveal the pivotal role of cofactor-substrate interaction in dihydrofolate reductase catalysis

Adesina, Aduragbemi S. ORCID: https://orcid.org/0000-0002-1029-4159, Świderek, Katarzyna, Luk, Louis Y. P., Moliner, Vicent and Allemann, Rudolf K. (2020) Electric field measurements reveal the pivotal role of cofactor-substrate interaction in dihydrofolate reductase catalysis. ACS Catalysis, 10 (14). pp. 7907-7914. ISSN 2155-5435

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Abstract

The contribution of ligand-ligand electrostatic interaction to transition state formation during enzyme catalysis has remained unexplored, even though electrostatic forces are known to play a major role in protein functions and have been investigated by the vibrational Stark effect (VSE). To monitor electrostatic changes along important steps during catalysis, we used a nitrile probe (T46C-CN) inserted proximal to the reaction center of three dihydrofolate reductases (DHFRs) with different biophysical properties, Escherichia coli DHFR (EcDHFR), its conformationally impaired variant (EcDHFR-S148P), and Geobacillus stearothermophilus DHFR (BsDHFR). Our combined experimental and computational approach revealed that the electric field projected by the substrate toward the probe negates those exerted by the cofactor when both are bound within the enzymes. This indicates that compared to previous models that focus exclusively on subdomain reorganization and protein-ligand contacts, ligand-ligand interactions are the key driving force to generate electrostatic environments conducive for catalysis.

Item Type:	Article
Uncontrolled Keywords:	electrostatics,dihydrofolate reductase,vibrational stark effects,protein dynamics,electric fields
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	LivePure Connector
Date Deposited:	03 Aug 2021 00:02
Last Modified:	25 Sep 2024 15:38
URI:	https://ueaeprints.uea.ac.uk/id/eprint/80955
DOI:	10.1021/acscatal.0c01856

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