Arctic adaptation in whale hemoglobin: interplay of carbon dioxide and temperature in the oxygen unloading.
The functional properties of hemoglobin from the whale Balaenoptera acutorostrata have been characterized as a function of pH, CO2, organic phosphates and temperature. Carbon dioxide effect does not depend on the presence of organic phosphates such as 2,3-DPG and P6-inositol while it is strongly affected by temperature, so that at 37 degrees C it is completely abolished. This, together with the very small delta H of oxygen binding (delta H = -4 to -2 Kcal/mol of oxygen at pH 7.4) has been physiologically interpreted on the basis of the specific metabolic needs of fins and tail which are the place of a great muscular activity.
Giardina
B
B
Department of Experimental Medicine and Biochemical Sciences, II University of Rome, Italy.
Ekker
M
M
Condó
S G
SG
Scatena
R
R
Clementi
M E
ME
Brix
O
O
D000222:Adaptation, Physiological; D000818:Animals; D001110:Arctic Regions; D002245:Carbon Dioxide / Q000097:blood; D002591:Cetacea / Q000097:blood*; D003080:Cold Temperature; D006454:Hemoglobins / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood; D010108:Oxyhemoglobins / Q000378:metabolism; D014907:Whales / Q000097:blood* / Q000502:physiology
D006454:Hemoglobins; D010108:Oxyhemoglobins; D002245:Carbon Dioxide; D010100:Oxygen