Biochemical Changes in Human Erythrocyte Membranes during Prolonged Cold Storage Under Blood Bank Conditions
Final rept. 1 Aug 1983-31 Jul 1984
JOHNS HOPKINS UNIV BALTIMORE MD SCHOOL OF MEDICINE
Pagination or Media Count:
Initial goals of the research on blood aged under blood bank conditions were to evaluate the possible role of elevation in intracellular calcium in mediating damage to the membrane skeleton of these cells. The possible elevation of intracellular calcium in aged red cells was evaluated by determining the extent of degradation of ankyrin, a protein known to be extremely sensitive to calcium-mediated proteolysis. Blood aged up to 8 weeks showed no increase in degradation of ankyrin, as determined by immunoblot analysis using affinity purified antibody against human erythrocyte ankyrin. These results suggested that the aged erythrocyte does not experience elevations of free intracellular calcium above 1-10uM, which is the range of concentrations where proteolysis of ankyrin occurs. The initial hypothesis concerning a role for calcium in mediating damage to stored erythrocytes thus was most likely incorrect. Other experiments directed towards understanding normal erythrocyte were more successful. Four new proteins were purified and characterized from human erythrocytes myosin, clathrin, clathrin uncoating protein, and a major calmodulin-binding protein associated with the membrane skeleton. In another study also partially funded by the contract the anion transporter was identified as a possible receptor for the malaria parasite P. falciparum.
- Anatomy and Physiology
- Medicine and Medical Research