Crystal structure of Trypanosoma cruzi heme peroxidase and characterization of its substrate specificity and compound I intermediate

Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved..

The protozoan parasite Trypanosoma cruzi is the causative agent of American trypanosomiasis, otherwise known as Chagas disease. To survive in the host, the T. cruzi parasite needs antioxidant defense systems. One of these is a hybrid heme peroxidase, the T. cruzi ascorbate peroxidase-cytochrome c peroxidase enzyme (TcAPx-CcP). TcAPx-CcP has high sequence identity to members of the class I peroxidase family, notably ascorbate peroxidase (APX) and cytochrome c peroxidase (CcP), as well as a mitochondrial peroxidase from Leishmania major (LmP). The aim of this work was to solve the structure and examine the reactivity of the TcAPx-CcP enzyme. Low temperature electron paramagnetic resonance spectra support the formation of an exchange-coupled [Fe(IV)=O Trp233•+] compound I radical species, analogous to that used in CcP and LmP. We demonstrate that TcAPx-CcP is similar in overall structure to APX and CcP, but there are differences in the substrate-binding regions. Furthermore, the electron transfer pathway from cytochrome c to the heme in CcP and LmP is preserved in the TcAPx-CcP structure. Integration of steady state kinetic experiments, molecular dynamic simulations, and bioinformatic analyses indicates that TcAPx-CcP preferentially oxidizes cytochrome c but is still competent for oxidization of ascorbate. The results reveal that TcAPx-CcP is a credible cytochrome c peroxidase, which can also bind and use ascorbate in host cells, where concentrations are in the millimolar range. Thus, kinetically and functionally TcAPx-CcP can be considered a hybrid peroxidase.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:298

Enthalten in:

The Journal of biological chemistry - 298(2022), 8 vom: 01. Aug., Seite 102204

Sprache:

Englisch

Beteiligte Personen:

Freeman, Samuel L [VerfasserIn]
Skafar, Vera [VerfasserIn]
Kwon, Hanna [VerfasserIn]
Fielding, Alistair J [VerfasserIn]
Moody, Peter C E [VerfasserIn]
Martínez, Alejandra [VerfasserIn]
Issoglio, Federico M [VerfasserIn]
Inchausti, Lucas [VerfasserIn]
Smircich, Pablo [VerfasserIn]
Zeida, Ari [VerfasserIn]
Piacenza, Lucía [VerfasserIn]
Radi, Rafael [VerfasserIn]
Raven, Emma L [VerfasserIn]

Links:

Volltext

Themen:

42VZT0U6YR
9007-43-6
Antioxidants
Ascorbate
Ascorbate Peroxidases
Ascorbic Acid
Chagas disease
Cytochrome c
Cytochrome-c Peroxidase
Cytochromes c
EC 1.11.1.-
EC 1.11.1.11
EC 1.11.1.5
EC 1.11.1.7
Heme
Journal Article
Oxidants
PQ6CK8PD0R
Peroxidase
Peroxidases
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 08.09.2022

Date Revised 20.10.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jbc.2022.102204

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM342933264