title: ATP-dependent degradation of 125I-bovine serum albumin by rabbit reticulocytes does not need repression of an endogenous inhibitor.
abstract: The ubiquitin-dependent proteolysis of 125I-bovine serum albumin in rabbit reticulocytes has been investigated. Using various reticulocyte fractions (reticulocyte protease, inhibitor-free protease, "ubiquitin" and "inhibitor") in the presence or absence of ATP, we found that the repression of an endogenous inhibitor, as suggested by others for alpha-casein proteolysis, is unlikely for bovine serum albumin. Therefore, differences exist in the ATP-dependent proteolytic pathway of rabbit reticulocytes depending on the substrate. Fractionation of the reticulocyte ATP-dependent proteolytic system revealed at least two proteolytic and two inhibitory fractions involved in the proteolysis of bovine serum albumin.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D007457:Iodine Radioisotopes; D007700:Kinetics; D010447:Peptide Hydrolases / Q000097:blood; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D014452:Ubiquitins / Q000097:blood
chemical_list: D007457:Iodine Radioisotopes; D014452:Ubiquitins; D012710:Serum Albumin, Bovine; D000255:Adenosine Triphosphate; D010447:Peptide Hydrolases