A STUDY OF MEMBRANE-PROTEIN DEFECTS AND ALPHA-HEMOGLOBIN CHAINS OF RED BLOOD-CELLS IN HUMAN BETA-THALASSEMIA

  • 15 November 1989
    • journal article
    • research article
    • Vol. 264  (32) , 19092-19098
Abstract
The soluble pool of .alpha. hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, .beta.A hemoglobin chain labeled with [3H]N-ethylmaeimide. This pool of soluble .alpha. chains was 0.067 .+-. 0.017% of hemoglobin in blood of normal adult, 0.11 .+-. 0.03% in heterozygous .beta. thalassemia and ranged from 0.26 to 1.30% in homozygous .beta. thalassemia intermedia. This elevated pool of soluble .alpha. chains observed in human .beta. thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% in the most dense red blood cells. The amount of insoluble .alpha. chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In .beta. thalassemia intermedia the amount of insoluble .alpha. chains was correlated with the decreased spectrin content of red cell membrane and was associated with a decrease in ankyrin and with other abnormalities of the electrophoretic pattern of membrane proteins. The loss and topology of the reactive thiol groups of membrane proteins was determined by using [3H]N-ethylmaleimide added to membrane ghosts prior to urea and Triton X-100 electrophoresis. Spectrin and ankyrin were the major proteins with the most important decrease of thiol groups.