Tertiary conformational transition in sheep hemoglobins induced by reaction with 5,5 -dithiobis(2-nitrobenzoate) and by binding of inositol hexakisphosphate

Biophysical Chemistry
Kehinde O OkonjoJ Oyebamiji Babalola

Abstract

We have determined the second-order reverse rate constant, k(R), for the reaction of 5,5 -dithiobis(2-nitrobenzoate) - DTNB - with sheep hemoglobins as a function of pH from values of the second-order forward rate constant, k(F), and the equilibrium constant, K(equ), at 25 degrees C: k(R)=k(F)K(equ). We demonstrate that (i) inositol hexakisphosphate (inositol-P(6)) decreases k(F) and k(R) by increasing K(rt), the rright harpoon over left harpoont tertiary conformation transition constant; (ii) the conformation favored for both the forward and reverse reactions is the r conformation. For stripped hemoglobin we obtain from the k(F) data a t isomer population of 34.6% (+/-14) prior to reaction with DTNB; from the k(R) data we calculate a t isomer population of 44.8% (+/-4) following reaction with DTNB. In the presence of inositol-P(6) the latter value is increased to 79.5% (+/-2). These results demonstrate that an allosteric transition occurs on reaction with DTNB and on inositol-P(6) binding.

References

Dec 1, 1977·The Journal of Physiology·P J GoodfordR Wootton
Jul 5, 1976·Journal of Molecular Biology·E J HeidnerM F Perutz
Jan 1, 1990·Advances in Experimental Medicine and Biology·R A HollandJ F Hallam
Mar 1, 1990·Biophysical Journal·M C MardenC Poyart
Feb 13, 1990·Biochemistry·I LalezariM F Perutz
Mar 1, 1973·Comparative Biochemistry and Physiology. A, Comparative Physiology·C VandecasserieJ Léonis
Dec 1, 1971·European Journal of Biochemistry·C VandecasserieJ Léonis
Apr 1, 1967·The Biochemical Journal·D Beale
Nov 25, 1983·Journal of Molecular Biology·B Shaanan
Jan 15, 1980·Journal of Molecular Biology·J M Baldwin

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