Structures and oxygen affinities of crystalline human hemoglobin C (β6 Glu->Lys) in the R and R2 quaternary structures.

ABSTRACT: Recent crystallographic studies suggested that fully liganded human hemoglobin can adopt multiple quaternary conformations that include the two previously solved relaxed conformations, R and R2, whereas fully unliganded deoxyhemoglobin may adopt only one T (tense) quaternary conformation. An important unanswered question is whether R, R2, and other relaxed quaternary conformations represent different physiological states with different oxygen affinities. Here, we answer this question by showing the oxygen equilibrium curves of single crystals of human hemoglobin in the R and R2 state. In this study, we have used a naturally occurring mutant hemoglobin C (β6 Glu→Lys) to stabilize the R and R2 crystals. Additionally, we have refined the x-ray crystal structure of carbonmonoxyhemoglobin C, in

SUBMITTER: Shibayama N 

PROVIDER: S-EPMC3190907 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature