Hemoglobin Gun Hill: An Unstable Protein Associated with Chronic Hemolysis

A new unstable hemoglobin variant, hemoglobin Gun Hill, is reported. Two members of a Caucasian family were found to be heterozygous for the abnormal hemoglobin. Evidence of mild chronic hemolysis was found in both individuals.

Heinz-Ehrlich bodies were absent from the peripheral blood of the patients with hemoglobin Gun Hill, but Heinz-like inclusions were readily produced in their red cells upon in vitro incubation with the redox dyes brilliant cresyl blue or new methylene blue. Precipitation of hemoglobin occurred when solutions of hemoglobin Gun Hill were exposed to the dyes or were heated to 50 C. Previous studies have shown that there is a deletion of five amino acids in the β chains of hemoglobin Gun Hill. This results in impaired heme binding, and the abnormal molecule lacks half the expected number of heme groups. These structural alterations are probably responsible for the instability of the abnormal hemoglobin.

Studies of the relative rates of synthesis of hemoglobins A and Gun Hill, using in vitro and in vivo technics, indicated an increased turnover rate for the variant protein. The evidence also suggested that hemoglobin Gun Hill is synthesized more rapidly than hemoglobin A.