In:
Science, American Association for the Advancement of Science (AAAS), Vol. 318, No. 5855 ( 2007-11-30), p. 1464-1468
Abstract:
A persistent puzzle in the field of biological electron transfer is the conserved iron-sulfur cluster motif in both high potential iron-sulfur protein (HiPIP) and ferredoxin (Fd) active sites. Despite this structural similarity, HiPIPs react oxidatively at physiological potentials, whereas Fds are reduced. Sulfur K-edge x-ray absorption spectroscopy uncovers the substantial influence of hydration on this variation in reactivity. Fe-S covalency is much lower in natively hydrated Fd active sites than in HiPIPs but increases upon water removal; similarly, HiPIP covalency decreases when unfolding exposes an otherwise hydrophobically shielded active site to water. Studies on model compounds and accompanying density functional theory calculations support a correlation of Fe-S covalency with ease of oxidation and therefore suggest that hydration accounts for most of the difference between Fd and HiPIP reduction potentials.
Type of Medium:
Online Resource
ISSN:
0036-8075
,
1095-9203
DOI:
10.1126/science.1147753
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2007
detail.hit.zdb_id:
128410-1
detail.hit.zdb_id:
2066996-3
detail.hit.zdb_id:
2060783-0
SSG:
11
Permalink