BOTHROPS-ALTERNATUS HEMOGLOBIN COMPONENTS - OXYGEN-BINDING PROPERTIESAND GLOBIN CHAIN HYDROPHOBIC ANALYSIS

1. Bothrops alternatus oxyhemolysate showed two components by DE-52 ce llulose ion-exchange chromatography and polyacrylamide gel electrophor esis: Hb I representing 70% of the hemolysate and Hb II (30%); both ar e dimeric in the stripped form (mol.wt 32,500 Da) and tetrameric in th e presence of IHP (64,000 Da). 2. Hb I, Hb II and whole hemolysate sho wed functionally similar properties to those of Liophis miliaris, i.e. for the stripped form over the pH interval 7.2-8.9: log P50 values de creasing from +/- 0.1 to +/- -0.15 (thereby an alkaline Bohr effect); DELTAH+ = -0.38 and Hill coefficient values decreasing from n(H) = 1.5 to 1.0. In the presence of ATP, an abrupt decrease in O2 affinity occ urs and the log P50 values change from 1.0 to 0.05; the Bohr effect in creases to DELTAH+ = -0.7 whereas the n(H) values decrease from greate r-than-or-equal-to 2 to values close to unity. 3. For B. alternatus, a t a physiological pH range (7.8-9.0) the hemoglobin Bohr effect become s apparent only in the presence of ATP and this seems to be fundamenta l for the O2 uptake of the snake. 4. HPLC analysis of the globins show s eight different chains instead of four, as found in L. miliaris hemo globin, which corroborates the presence of Hb I and Hb II components i n B. alternatus, and also shows that the unique tetramer formed from d ifferent alpha and beta chains is also consistent in this snake.