Myoglobin oxygen dissociation by multi-wavelength spectroscopy.
Schenkman, Kenneth A., David R. Marble, David H. Burns, Eric O. Feigl.
Departments of Bioengineering and Physiology, University of
Washington, Seattle, Washington 98195, Department of Pediatrics,
University of Wisconsin, Madison, Wisconsin 53792, Department of
Chemistry, McGill University, Montreal, Quebec H3A 2K6
APStracts 3:0410A, 1996.
Multi-wavelength optical spectroscopy was used to determine the oxygen
binding characteristics for equine myoglobin. Oxygen binding
relationships as a function of oxygen tension were determined for
temperatures of 10, 25, 35, 37 and 40 degrees C, at pH 7.0. In
addition, dissociation curves were determined at 37 degrees C for pH
6.5, 7.0 and 7.5. Equilibration was achieved with a myoglobin
solution, at the desired temperature and pH, and 16 oxygen-nitrogen
gas mixtures of known oxygen fraction. Correction for the inevitable
presence of metmyoglobin was made using a three component least
squares analysis, and by correcting the end-point oxymyoglobin
spectra for the presence of metmyoglobin. A P50 for myoglobin of 2.39
mmHg was determined at pH 7.0 and 37 degrees C. The myoglobin
dissociation curve was well fit by the Hill equation: Saturation =
PO2/(PO2 + P50).
Received 13 March 1996; accepted in final form 21 August 1996.
APS Manuscript Number A252-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996