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Cytoglobin conformations and disulfide bond formation
Author(s) -
Lechauve Christophe,
Chauvierre Cédric,
Dewilde Sylvia,
Moens Luc,
Green Brian N.,
Marden Michael C.,
Célier Chantal,
Kiger Laurent
Publication year - 2010
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2010.07686.x
Subject(s) - chemistry , globin , kinetics , histidine , dimer , stereochemistry , dissociation (chemistry) , myoglobin , ligand (biochemistry) , intramolecular force , protein subunit , biophysics , crystallography , hemoglobin , amino acid , biochemistry , receptor , biology , organic chemistry , physics , quantum mechanics , gene
The oligomeric state and kinetics of ligand binding were measured for wild‐type cytoglobin. Cytoglobin has the classical globin fold, with an extension at each extremity of about 20 residues. The extended length of cytoglobin leads to an ambiguous interpretation of its oligomeric state. Although the hydrodynamic diameter corresponds to that of a dimer, it displays a mass of a single subunit, indicating a monomeric form. Thus, rather than displaying a compact globular form, cytoglobin behaves hydrodynamically like a tightly packed globin with a greater flexibility of the N‐ and C‐terminal regions. Cytoglobin displays biphasic kinetics after the photolysis of CO, as a result of competition with an internal protein ligand, the E7 distal histidine. An internal disulfide bond may form which modifies the rate of dissociation of the distal histidine and apparently leads to different cytoglobin conformations, which may affect the observed oxygen affinity by an order of magnitude.