Functional consequences of haem orientational disorder in sperm-whale and yellow-fin-tuna myoglobins

Ligand-binding kinetics of native and reconstituted sperm-whale myoglobin were studied in relation to haem orientational disorder by rapid kinetic methods. In addition, native yellow-fin-tuna myoglobin with significant amount of haem disorder was also used. The O2 dissociation and association rates...

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Bibliographic Details
Published in:Biochemical Journal
Main Authors: Aojula, H S, Wilson, M T, Morrison, I E G
Format: Article in Journal/Newspaper
Language:English
Published: Portland Press Ltd. 1987
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Online Access:http://dx.doi.org/10.1042/bj2430205
https://portlandpress.com/biochemj/article-pdf/243/1/205/589912/bj2430205.pdf
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Summary:Ligand-binding kinetics of native and reconstituted sperm-whale myoglobin were studied in relation to haem orientational disorder by rapid kinetic methods. In addition, native yellow-fin-tuna myoglobin with significant amount of haem disorder was also used. The O2 dissociation and association rates were found for the proteins with different degrees of haem disorder, and these results suggest that the isomers are characterized by almost identical kinetic parameters. Rates of CO recombination after photolysis were also identical for the two orientational isomers. The results clearly indicate that the rotation of the haem about the alpha-gamma meso axis has little or no effect on the ligand-binding properties of these myoglobins.