Role of the distal hydrogen-bonding network in regulating oxygen affinity in the truncated hemoglobin III from Campylobacter jejuni.

Arroyo Mañez, Pau and Lu, Changyuan and Boechi, Leonardo and Martí, Marcelo A and Shepherd, Mark and Wilson, Jayne Louise and Poole, Robert K and Luque, F Javier and Yeh, Syun-Ru and Estrin, Darío A (2011) Role of the distal hydrogen-bonding network in regulating oxygen affinity in the truncated hemoglobin III from Campylobacter jejuni. Biochemistry, 50 (19). pp. 3946-56. ISSN 1520-4995. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1021/bi101137n

Abstract

Oxygen affinity in heme-containing proteins is determined by a number of factors, such as the nature and conformation of the distal residues that stabilize the heme bound-oxygen via hydrogen-bonding interactions. The truncated hemoglobin III from Campylobacter jejuni (Ctb) contains three potential hydrogen-bond donors in the distal site: TyrB10, TrpG8, and HisE7. Previous studies suggested that Ctb exhibits an extremely slow oxygen dissociation rate due to an interlaced hydrogen-bonding network involving the three distal residues. Here we have studied the structural and kinetic properties of the G8(WF) mutant of Ctb and employed state-of-the-art computer simulation methods to investigate the properties of the O(2) adduct of the G8(WF) mutant, with respect to those of the wild-type protein and the previously studied E7(HL) and/or B10(YF) mutants. Our data indicate that the unique oxygen binding properties of Ctb are determined by the interplay of hydrogen-bonding interactions between the heme-bound ligand and the surrounding TyrB10, TrpG8, and HisE7 residues.

Item Type: Article
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: Mark Shepherd
Date Deposited: 01 Sep 2011 15:47
Last Modified: 15 Nov 2011 12:33
Resource URI: http://kar.kent.ac.uk/id/eprint/28107 (The current URI for this page, for reference purposes)
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