Protease activity in the human erythrocyte: localization to the cell
membrane
SK Ballas and ER Burka
Proteolytic activity in the mature human erythrocyte was localized to the
cell membrane. This activity, which could not be ascribed to contaminating
leukocytes in the suspension, was totally absent from the soluble portion
of the cell and was more active against hemoglobin subunits than against
tetrameric hemoglobin molecules. Pulse-chase experiments confirmed that the
membrane proteolytic activity was more active in degrading beta chains that
alpha chains. The activity could be extracted from erythrocyte cell
membranes, but not from membrane- free hemolysate, by exposure to 0.75-M
KSCN. The activity of the protease was dependent on time and temperature
and did not require ATP or an energy-generating system for activity.
Volume 53,
Issue 5,
pp. 875-882,
05/01/1979
Copyright © 1979 by The American Society of Hematology
