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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Multidimensional redox potential/pK(a) coupling in multicopper oxidases from molecular dynamics: implications for the proton transfer mechanism

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Author(s):
Santo, Anderson A. E. [1] ; Lazaroti, Vitor Hugo R. [1] ; Feliciano, Gustavo T. [1]
Total Authors: 3
Affiliation:
[1] Sao Paulo State Univ Unesp, Inst Chem, Enginerring Phys & Math Dept, Araraquara, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 23, n. 48 NOV 2021.
Web of Science Citations: 0
Abstract

Bilirubin oxidases (BOD) are metalloenzymes that catalyze the conversion of O-2 and bilirubin to biliverdin and water in the metabolism of chlorophyll and porphyrin. In this work we have used the CpHMD method to analyze the effects of the different oxidation states on the BOD trinuclear cluster (TNC). Our results demonstrate that there is a link between the different oxidation states of copper ions and the protonation capacity of nearby titratable residues. Each configuration affects pK(a) differently, creating proton gradients within the enzyme that act in an extremely orderly manner. This order is closely linked to the catalytic mechanism and leads us to the conclusion of the entry of the O-2 molecule and its reduction in water molecules is associated with the probability of the release of protons from nearby acid groups. With this information, we deduce that under the initial reaction conditions the acidic side chains of nearby residues can be protonated; this allows the enzyme to reduce the activation energy of the reaction by coupling the proton transfer to oxidation state changes in the metallic center. (AU)

FAPESP's process: 17/13401-4 - Computational simulation of redox processes in complex environments
Grantee:Gustavo Troiano Feliciano
Support Opportunities: Regular Research Grants
FAPESP's process: 20/04339-6 - Redox state and pH influence on the molecular and electronic structure of proteins with interest in bioelectrochemistry
Grantee:Vitor Hugo Rangel Lazaroti
Support Opportunities: Scholarships in Brazil - Scientific Initiation