Bovine erythrocyte hemoglobin is used as a substrate for pepsin and other proteases.
Hemoglobin is composed of one globin plus four hemes; heme consists of protoporphyrin IX and ferrous iron. The iron content of human hemoglobin is 0.338% (w/w) which gives a minimal molecular weight of 16,520; however, ultracentrifugal and osmotic pressure measurements indicate an actual molecular weight four times the minimum molecular weight (Henry 1968).
Pauling (1948) has shown that the chemical characteristics of hemoglobin result from the electrical and magnetic interaction of the iron and the porphyrin ring which prevents the ferrous iron from forming further bonds with most substances other than O2 and CO, which form covalent bonds with the ferrous ion. Determination of the hemoglobin content of whole blood has been the most common quantitative clinical analysis for at least a half century.
Characteristics of Hemoglobin from Bovine Erythrocytes:
Stability: Stable for years if kept dry.
Storage: Store at 2-8°C.