-transparent.png){kind=logo}
A thin-layer gas-solution microcalorimeter has been developed to study the binding reactions of gaseous ligands with ligand binding macromolecules. We have measured the enthalpy of binding oxygen and carbon monoxide to horse myoglobin, human hemoglobin A0 and sperm whale myoglobin in phosphate buffer at pH 7.6, with the enzyme reducing system of Hayashi. Reactions of human hemoglobin were also done under various buffer conditions in order to elucidate the Bohr effect. These binding reactions were found not to exhibit a detectable enthalpy change over the temperature range of 10 degrees C to 25 degrees C. The enzyme reducing system was shown to react with oxygen in a manner that releases a substantial amount of heat. This problem was corrected by using a minimum amount and by placing the buffer and enzyme system in the reference cell effectively cancelling the oxygen enzyme reaction heat as well as the heat of gas dissolution. It was also demonstrated that glucose-6-phosphate, one of the reducing system components, in 50 mM concentrations can influence the heat of binding oxygen and carbon monoxide to hemoglobin. This effect was shown to be absent in the myoglobins and also with hemoglobin at glucose-6-phosphate concentrations less than 5 mM.
C R Johnson, and
S J Gill, and
K S Peters
August 1978,
Journal of molecular biology,
C R Johnson, and
S J Gill, and
K S Peters
August 1987,
The Journal of biological chemistry,
C R Johnson, and
S J Gill, and
K S Peters
March 1975,
Proceedings of the National Academy of Sciences of the United States of America,
C R Johnson, and
S J Gill, and
K S Peters
March 1989,
Biochemistry,
C R Johnson, and
S J Gill, and
K S Peters
April 1972,
Proceedings of the National Academy of Sciences of the United States of America,
C R Johnson, and
S J Gill, and
K S Peters
April 1977,
Analytical biochemistry,
C R Johnson, and
S J Gill, and
K S Peters
December 1976,
Journal of applied physiology,
C R Johnson, and
S J Gill, and
K S Peters
January 1965,
Ukrains'kyi biokhimichnyi zhurnal,
C R Johnson, and
S J Gill, and
K S Peters
October 1958,
Archives of biochemistry and biophysics,
C R Johnson, and
S J Gill, and
K S Peters
June 1976,
FEBS letters,
