Dimer-tetramer Transition In Hemoglobins From Liophis Miliaris-ii. Evidence With The Stripped Proteins

1. 1. Whole Liophis miliaris hemolysate stored under refrigeration at pH 7 becomes progressively deoxygenated and presents two hemoglobin forms of mol. wts 32,500 and 64,000, consistent with oxydimers and deoxytetramers respectively. 2. 2. The Hill plot determined at pH 6.5 considering oxygen pressure capable to saturate up to 50% of the hemoglobin shows a coefficient value of nH = 2.06, whereas that found at higher oxygen pressure was nH = 0.85. 3. 3. The apparent Bohr effect of about ΔH+ = -0.4 in the stripped hemoglobin was explained by the increase of co-operative deoxytetramer T-state/non-co-operative ratio as a function of proton concentration. © 1990.961119122Focesi, Jr., Ogo, Bonaventura, Bonaventura, Kinetics of oxygen and carbon monoxide binding to the hemoglobins of the water snakes Liophis miliaris and Helicops modestus (1980) Comp. Biochem. Physiol., 67 B, pp. 555-559Matsuura, Ogo, Focesi, Jr, Dimer-tetramer transition in hemoglobins from Liopis miliaris—I. Effect of organic polyphosphates (1987) Comp. Biochem. Physiol., 86 A, pp. 683-687Matsuura, Fushitani, Riggs, The amino acid sequences of the α and β chains of hemoglobin from the snake, Liophis miliaris (1989) J. biol. Chem., 265, pp. 5515-5521McDonald, Turci, Bleichman, Stinson, Functional and sub-unit assembly properties of hemoglobin Alberta (α2β2 101 Glu → Gly) (1985) J. molec. Biol., 183, pp. 105-112Monod, Wyman, Changeaux, On the nature of allosteric transition: a plausible model (1965) J. molec. Biol., 12, pp. 88-118Ogo, Abe, Focesi, Jr, Oxygen dissociation constants in hemoglobins of Helicops modestus and Liophis miliaris two water-snakes with different morphological adaptations to their aquatic environment (1979) Comp. Biochem. Physiol., 63 A, pp. 285-289Ogo, Matsuura, Focesi, Jr, Content of organic polyphosphate and their allosteric effects on haemoglobins from the water-snakes Helicops modestus and Liophis miliaris (1984) Comparative Biochemistry and Physiology Part A: Physiology, 82 A, pp. 587-58