The characterization of hemoglobin Manitoba or alpha sub(2)102(G9)Ser arrow right Arg beta sub(2) and hemoglobin Contaldo or alpha sub(2)103(G10)His arrow right Arg beta sub(2) by high performance liquid chromatography

Hb Contaldo with a His arrow right Arg substitution at position 103(G10) of the alpha chain is a newly discovered unstable Hb variant observed in an Italian child. Its instability is probably due to the disruption of the hydrogen bond between alpha 103(G10)His and beta 108(G10)Asn. The structural variation in the core segment was determined through analysis of tryptic peptides from digests of the alpha super(X) and oxidized alpha super(X) (with performic acid) chains, which were separated by HPLC. Similar analyses were made for the alpha super(X) chain of the rare Hb Manitoba in which alpha 102(G9)Ser is replaced by Arg. This variant was observed for the first time in an Italian patient, and was also studied in a member of a previously described Canadian family.