INVESTIGADORES
VILA Alejandro Jose
artículos
Título:
Alternative ground states enable pathway switching in biological electron transfer
Autor/es:
ABRIATA LA; ALVAREZ PAGGI, D; LEDESMA, GN; BLACKBURN, N.J; VILA, AJ; MURGIDA, D
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Editorial:
NATL ACAD SCIENCES
Referencias:
Lugar: Washington DC, USA; Año: 2012 vol. 109 p. 17348 - 17353
ISSN:
0027-8424
Resumen:
Electron transfer is the simplest chemical reaction and constitutes the
basis of a large variety of biological processes, such as photosynthesis
and cellular respiration. Nature has evolved specific proteins and
cofactors for these functions. The mechanisms optimizing biological
electron transfer have been matter of intense debate, such as the role
of the protein milieu between donor and acceptor sites. Here we propose a
mechanism regulating long-range electron transfer in proteins.
Specifically, we report a spectroscopic, electrochemical, and
theoretical study on WT and single-mutant Cu(A) redox centers from
Thermus thermophilus, which shows that thermal fluctuations may populate
two alternative ground-state electronic wave functions optimized for
electron entry and exit, respectively, through two different and nearly
perpendicular pathways. These findings suggest a unique role for
alternative or "invisible" electronic ground states in directional
electron transfer. Moreover, it is shown that this energy gap and,
therefore, the equilibrium between ground states can be fine-tuned by
minor perturbations, suggesting alternative ways through which
protein-protein interactions and membrane potential may optimize and
regulate electron-proton energy transduction.