PMID: 9223274

Authors:

Schumacher MA, Zheleznova EE, Poundstone KS, Kluger R, Jones RT, Brennan RG

Title:

Allosteric intermediates indicate R2 is the liganded hemoglobin end state.

Journal:

Proc Natl Acad Sci U S A. 1997 Jul 22;94(15):7841-4.

Abstract:

Hemoglobin has been a long-standing paradigm for understanding protein allostery. Here, the x-ray structures of two chemically crosslinked, fully liganded hemoglobins, alpha2beta82CA82beta and alpha2beta82ND82beta, are described at 2.3 A and 2.6 A resolution, respectively. Strikingly, these crosslinked hemoglobins assume intermediate conformations that lie between those of R and the controversial liganded hemoglobin state R2 rather than between R and T. Thus, these structures support only a T left and right arrow R left and right arrow R2 allosteric pathway and underscore the physiological importance of the R2 conformation.