Heterogeneity of the hemoglobin of the Ohrid trout (Salmo L. typicus)

We have analyzed the hemoglobins of five individual trout from the Ohrid Lake (Salmo L. typicus) by electrophoretic methods, by reversed-phase high-performance liquid chromatography, and by limited structural analyses. The two major classes of hemoglobin are type I (35% of total) and type IV (65%). Type IV is the major oxygen-transporting hemoglobin; it consists of three types of beta chain (in about equal quantities) and three types of alpha chain (one major and two minor types). Several structural differences have been observed between these three beta (IV) chains and between the three alpha (IV) chains, suggesting a complex genetic system governing the synthesis of these proteins. Moreover, a few amino acid substitutions occur at positions involved in contacts between chains, which suggests that differences in oxygen affinity may exist between these various type IV hemoglobins. Type I hemoglobin is less complex because it contains one type of beta chain and two alpha chains; the latter two differ in numerous positions, suggesting duplications of the alpha (I)-globin gene. The alpha and beta chains of type I hemoglobin differ considerably from the alpha and beta chains of type IV hemoglobin, indicating the existence of alpha (I)- and beta (I)-globin genes separate from the alpha (IV)- and beta (IV)-globin genes.