Effects of allosteric effectors on oxygen binding to crystals of hemoglobin in the R-quaternary structure.

ABSTRACT: Much is known about how allosteric effectors influence the equilibrium between the relaxed (R) and tense (T) states of hemoglobin (Hb), but little is known about how and to what extent the effectors lower the intrinsic O₂ affinity of each allosteric state, especially the R-state. Here, we provide a thorough characterization of the O₂ equilibria of effector-bound and unbound R-quaternary form crystals of horse Hb without a quaternary structural switching. In the absence of effectors, R crystals of horse Hb were shown to bind O₂ noncooperatively with a very high affinity virtually identical to that of R crystals of human Hb. We found that the effector bezafibrate (BZF) and its derivative L35 lower the overall O₂ affinity of R crystals by approximat

SUBMITTER: Shibayama N 

PROVIDER: S-EPMC11632842 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature