Non-site-specific allosteric effect of oxygen on human hemoglobin under high oxygen partial pressure.

ABSTRACT: Protein allostery is essential for vital activities. Allosteric regulation of human hemoglobin (HbA) with two quaternary states T and R has been a paradigm of allosteric structural regulation of proteins. It is widely accepted that oxygen molecules (O2) act as a "site-specific" homotropic effector, or the successive O2 binding to the heme brings about the quaternary regulation. However, here we show that the site-specific allosteric effect is not necessarily only a unique mechanism of O2 allostery. Our simulation results revealed that the solution environment of high O2 partial pressure enhances the quaternary change from T to R without binding to the heme, suggesting an additional "non-site-specific" allosteric effect of O2. The latter effect should play a complementary role in the quater

SUBMITTER: Takayanagi M 

PROVIDER: S-EPMC3978498 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature