Studies on Thermostability of Hemoglobins in Sheep

Abstract

An investigation was undertaken on thermostability of two adult hemoglobins, Hb-A and Hb-B and the relationship between thermostability and resistance to alkali denaturation of these hemoglo-bins, and the osmotic fragility of red blood cells to hypotonic saline. The results are as follows:1. Adult hemoglobin, Hb-B, proved to have significantly higher resistance than Hb-A to dena-turation by heating at 70°C within 9 minutes. Thermostability of different types of hemoglobin was in the order of Hb B>Hb AB>Hb A. 2. In an alkali denaturation test, Hb-A had signifi-cantly higher resistance than Hb-B to denaturation by treatment with 0.1N NaOH. Resistance to denaturation by alkali of different types of hemoglobin was in the order of Hb A>Hb AB>Hb B. 3. There was a negative correlation between resistance of hemoglobin to heat and alkali denaturations (r=-0.488). A tendency was observed that hemoglobin of type Hb B with high resistance to denaturation by heat showed low resistivity to denaturation by alkali. Hemoglobin of type Hb A had an opposite tendency to that of type Hb B. 4. A significant difference was found in osmotic fragility to hypotonic saline between the red blood cells of types Hb B and Hb AB. The red blood cells of type Hb B were less fragile to hypotonic saline than those of type Hb AB. Thermostability of hemoglobins and osmotic fragility of red blood cells were negatively correlated (r=-0.633).