IX. GENETICS AND HUMAN HEMOGLOBIN CHEMISTKV 



423 



A. Hb-A VARIANTS — CHEMICAL STUDIES 



The abnormal forms of Hb-A represent the largest and best known 

 group of abnormal hemoglobins. Most of the chemical studies have been 

 carried out on variants of Hb-A and our knowledge of the inheritance 

 of the hemoglobin genes and of the population distribution of the 



TABLE II 



Chemical Studies of the Hb-A Variants 



" The charge difference with Hb-A at pH 8.6 is the theoretical charge difference 

 based on the amino acid substitution and expressed in arbitrary units. 



* For the peptide nomenclature see Table I and Gerald and Ingram (1961). 



'The Hb-M's are observed as methemoglobins (Fe++'*'); the formation of internal 

 complexes between the iron and the substituting amino acids neutralizes the charge 

 difference with oxy-Hb-A (Fe+"'"). The Hb-M's show a slightly different electrophoretic 

 mobility compared to Hb-A (see Gerald and Efron, 1961). Table continued 



