Open AccessPurification, crystallization and preliminary X‐ray analysis of haemoglobin from ostrich ( Struthio camelus )
Author(s) -
Sundaresan S. S.,
Ramesh P.,
Sivakumar K.,
Ponnuswamy M. N.
Publication year - 2009
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309109019009
Subject(s) - struthio , inositol , crystallization , chemistry , oxygen , hemoglobin , allosteric regulation , whole blood , blood typing , crystallography , chromatography , biology , biochemistry , anatomy , receptor , immunology , organic chemistry
Haemoglobin is a tetrameric protein that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. The oxygen‐binding properties of haemoglobin are regulated through the binding of allosteric effectors. The respiratory system of avian species is unique and complex in nature when compared with that of mammals. In avian species, inositol pentaphosphate (inositol‐P 5 ) is present in the erythrocytes of the adult and is thought to be the major factor responsible for the relatively high oxygen affinity of the whole blood. The ostrich ( Struthio camelus ) is a large flightless bird which contains inositol tetrakisphosphate (inositol‐P 4 ) in its erythrocytes and its whole blood oxygen affinity is higher. Efforts have been made to explore the structure–function relationship of ostrich haemoglobin. Ostrich haemoglobin was purified using ion‐exchange chromatography. Haemoglobin crystals were grown by the hanging‐drop vapour‐diffusion method using PEG 3350 as the precipitant in 50 m M phosphate buffer pH 7.2. Data were collected using a MAR345 image‐plate detector system. The crystals of ostrich haemoglobin diffracted to 2.2 Å resolution. They belonged to the orthorhombic space group P 2 1 2 1 2 1 with one whole biological molecule in the asymmetric unit; the unit‐cell parameters were a = 80.93, b = 81.68, c = 102.05 Å.