title: Changes in proteinase and peptidase activities during reticulocyte maturation.
abstract: The ability of rabbit reticulocytes to degrade puromycin-peptides and aminoethylcysteine-induced aberrant polypeptides decreased during cellular maturation. Cell-free studies indicate that the fall in proteolytic activity is not a consequence of accumulation of proteinase inhibitors or the conversion of all of the abnormal protein into undegradable forms. A decrease in peptidase activity using seven dipeptides and one tripeptide as substrates was also found to accompany reticulocyte maturation. Addition of the aminopeptidase B inhibitor bestatin to reticulocyte extracts did not inhibit the conversion of acid-precipitable puromycin-peptides to acid-soluble products; bestatin did induce the accumulation of very low molecular weight material (possibly di- or tripeptides) within the acid soluble fraction.
mesh_terms: D000818:Animals; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D010450:Endopeptidases / Q000097:blood*; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000097:blood*; D011691:Puromycin / Q000097:blood; D011817:Rabbits; D012156:Reticulocytes / Q000187:drug effects / Q000201:enzymology*
chemical_list: C000204:S-2-aminoethyl cysteine; D011691:Puromycin; D010450:Endopeptidases; D010447:Peptide Hydrolases; D007930:Leucine; C012211:ubenimex; D003545:Cysteine