The functional properties of amphibian hemoglobin: The case of Salamander salamander and Hydromantes genei

Abstract

1. 1. The ligand-binding properties of hemoglobins from the urodelan amphibians Salamander salamander and Hydromantes genei genei have been studied and compared with those of hemoglobins from the urodelan, Triturus cristatus (Condó et al., 1980; Condò et al., 1983). 2. 2. Depending on the experimental conditions, the Bohr effect is absent or reversed in S. salamander hemoglobin, similarly to almost all the known hemoglobins from the Urodela (and tadpoles of both Anurans and the Urodela). 3. 3. H. genei shares, with anuran amphibia, a normal Bohr effect (reduced oxygen affinity of hemoglobin at acid pH), although smaller than that of mammals. 4. 4. The difference in the Bohr coefficient of hemoglobin from members of the two major subclasses of amphibians (Anura and Urodela: −0.3 and + 0.1, respectively, averaged from data of Table 1), almost vanishes in the whole blood (−0.2 to −0.4 in the two groups), due to the presence of intracellular effectors. 5. 5. Biochemical and physiological implications of the (apparent) reverse Bohr effect are reviewed.