Oxygenation properties and underlying molecular mechanisms of hemoglobin in plateau zokor (Eospalax baileyi).

Oxygenation properties and underlying molecular mechanisms of hemoglobin in plateau zokor (Eospalax baileyi).
Am J Physiol Regul Integr Comp Physiol. 2019 Sep 11;:
Authors: Pu P, Lu S, Niu Z, Zhang T, Zhao Y, Yang X, Zhao Y, Tang X, Chen Q
Abstract
The plateau zokor (Eospalax baileyi) is a species of subterranean rodent endemic to the Tibetan Plateau. It's well adapted to the cold, hypoxic and hypercapnic burrow. In order to study the oxygenation properties of plateau zokor hemoglobins (Hbs), we measured intrinsic Hb-O2 affinities and their sensitivities to pH (Bohr effect), CO2, Cl-, 2,3-diphosphoglycerate (DPG) and temperature using purified Hbs from zokor and mouse. The optimal deoxyhemoglobin model of plateau zokor was constructed and used to study its structural characteristics by molecular dynamics simulations. O2-binding results revealed that plateau zokor Hbs exhibit remarkably high intrinsic Hb-O2 affinity, low CO2 effects compared with human and the relatively low anion allosteric effector sensitivities (DPG and Cl-) at normal temperature, which would safeguard the pulmonary Hb-O2 loading under hypoxic and hypercapnic conditions. Furthermore, the high anion allosteric effector sensitivities at low temperature and low temperature sensitivities of plateau zokor Hbs would facilitate the releasing of O2 in cold extremities and metabolic tissues. However, the high Hb-O2 affinity of plateau zokor is not compensated by high pH sen...

Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - September 10, 2019 Category: Physiology Authors: Pu P, Lu S, Niu Z, Zhang T, Zhao Y, Yang X, Zhao Y, Tang X, Chen Q Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research