Studies of the hemoglobins of the eel (Anguilla anguilla L.)-II. Proton binding of a component with a negative Bohr effect

Abstract

1. 1. The multiple hemoglobins of European eel (Anguilla anguilla L.) were separated and one isolated component (called HbE1) was studied with respect to its acid-base titration behavior. 2. 2. HbE1 has a low buffer capacity in the neutral pH range, similar to the buffer capacity of the hemoglobin mixture recently reported (Breepoel et al., 1980). 3. 3. The low buffer capacity is probably due to the small number of neutral titratable groups, particularly histidines. 4. 4. Both acid-base titrations of deoxy- and oxyHbE1 and fixed-acid Haldane measurements point to a negative Bohr-Haldane effect in the physiological pH range. 5. 5. The fixed-acid Haldane effect at pH 7.0 is nearly abolished upon the addition of saturating amounts of the endogenous organic phosphate GTP. © 1981.