Publication
Title
Unusual flexibility of distal and proximal histidine residues in the haem pocket of **Drosophila melanogaster** haemoglobin
Author
Abstract
Several pH-dependent low-spin ferric haem forms are identified in a frozen solution of the ferric 121CysSer mutant of Drosophila melanogaster haemoglobin (DmHb1*) using electron paramagnetic resonance (EPR) techniques. Different forms with EPR parameters typical of bis-histidine coordinated haem iron centers were observed. Strong pH-dependent changes in the EPR signatures were observed related to changes in the haem pocket. The pulsed EPR data indicate that both the distal and proximal histidine exhibit a large libration around the FeNHis axis. The resonance Raman spectra of the CO-ligated ferrous form of Drosophila melanogaster haemoglobin are typical of an open conformation, with little stabilization of the CO ligand by the surrounding amino-acid residues. The EPR data of the cyanide-ligated ferric DmHb1* indicates a close similarity with cyanide-ligated ferric myoglobin. The structural characteristics of DmHb1* are found to clearly differ from those of other bis-histidine-coordinated globins.
Language
English
Source (journal)
Metallomics / Royal Society of Chemistry [London] - Cambridge
Publication
Cambridge : 2009
ISSN
1756-5901
Volume/pages
1:3(2009), p. 256-264
ISI
000269034300009
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 04.11.2009
Last edited 03.08.2017
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