Abstract

In this paper allosteric interactions in protonmotive heme aa3 terminal oxidases of respiratory chain are dealt with. The different lines of evidence supporting the key role of H+/e- coupling (redox Bohr effect) at the low spin heme a in the proton pump of the bovine oxidase are summarized. Results are presented showing that the I-R54M mutation in P. denitrificans aa3 oxidase, which decreases by more than 200 mV the Em of heme a, inhibits proton pumping. Mutational aminoacid replacement in proton channels, at the negative (N) side of membrane-inserted prokaryotic aa3 oxidases, as well as Zn2 + binding at this site in the bovine oxidase, uncouple proton pumping. This effect appears to result from alteration of the structural/functional device, closer to the positive, opposite (P) surface, which separate pumped protons from those consumed in the reduction of O2 to 2 H2O. This article is part of a Special Issue entitled: Respiratory Oxidases

Autore Pugliese

• Capitanio Giuseppe , Palese Luigi Leonardo

Tutti gli autori

• CAPITANIO G.;PALESE L.L.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2012

ISSN

0005-2728

ISBN

Non Disponibile

Numero di citazioni Wos

10

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

12

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile