| Popis: |
Bothrops alternatus oxyhemolysate showed two components by DE-52 cellulose ion- exchange chromatography and polyacrylamide gel electrophoresis: Hb I representing 70% of the bemolysate and Hb II (30%); both are dimeric in the stripped form (mol.wt 32,500 Da) and tetrameric in the presence of IHP (64,000 Da). 2. Hb I, Hb II and whole hemolysate showed functionally similar properties to those ofLiophis miliaris, i.e. for the stripped form over the pH interval 7.2-8.9: log Ps0 values decreasing from +0.1 to + -0.15 (thereby an alkaline Bohr effect); AH + = -0.38 and Hill coefficient values decreasing from n a = 1.5 to 1.0. In the presence of ATP, an abrupt decrease in 02 affinity occurs and the log Ps0 values change from 1.0 to 0.05; the Bohr effect increases to AH + = -0.7 whereas the n n values decrease from I>2 to values dose to unity. 3. For B. alternatus, at a physiological pH range (7.8-9.0) the hemoglobin Bohr effect becomes apparent only in the presence of ATP and this seems to be fundamental for the 02 uptake of the snake. 4. HPLC analysis of the globins shows eight different chains instead of four, as found in L. miliaris hemoglobin, which corroborates the presence of Hb I and Hb II components in B. alternatus, and also shows that the unique tetramer formed from different ct and fl chains is also consistent in this snake. |
