Selective proteolysis of abnormal proteins of shortened chain length in rabbit reticulocytes.

Proteolysis of certain shortened globin chains can proceed in cell-free extracts of rabbit reticulocytes in the absence of ATP. Proteolysis of amino acid analogue-induced abnormal globin chains of normal chain length may be stimulated by ATP, however. The ATP independent degradation of globin cyanogen bromide-peptides appears to require the presence of free, unblocked amino groups in the substrate, has a pH optimum of 7.8 and is inhibited by phenanthroline, cobalt and zinc ions, N-ethylmaleimide and cystamine.