Protease and peptidase activities during reticulocyte maturation
Hipkiss, A.R.; McKay, M.J.; Daniels, R.S.; Atkinson, E.M.; Worthington, V.C.; Wharton, S.A.
Biomedica Biochimica Acta 42(11-12): S212-S217
1983
ISSN/ISBN: 0232-766X PMID: 6372793 Document Number: 199913
Rabbit reticulocytes were fractionated according to buoyant density on albumin gradients. The properties of fractionated cells were consistent with the thesis that the procedure separated the reticulocytes according to their degree of maturation. Catabolism of aminoethylcysteine-induced abnormal protein and puromycin-peptides declined with increasing cellular maturity. Cell-free extracts showed a similar decrease in degradative activity: addition of extracts of young cells stimulated proteolysis in extracts from old cells. Peptidase activity also declined during maturation. In the more mature cells abnormal protein was located increasingly in the cell-debris fraction, analogous to Heinz bodies.