Cathepsin D in erythroid cells.
We have detected, solubilized, and purified to near-homogeneity a membrane-bound acid protease from rabbit reticulocytes. Chemical, physical, immunological, and catalytic characterization demonstrate that the enzyme is cathepsin D. With cytochrome b5 as substrate, the enzyme shows a surprisingly high pH optimum and is stimulated by ATP and DPG. Possible roles for the protease include protein processing of microsomal enzymes, degradation of subcellular organelles, and destruction of excess hemoglobin chains. The possible role of cathepsin D in protein processing of microsomal enzymes will be best assessed by the molecular biological approaches described in the following two presentations.
Hultquist
D E
DE
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606.
Rodriguez
C
C
Schafer
D A
DA
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002402:Cathepsin D / Q000097:blood* / Q000302:isolation & purification / Q000502:physiology; D003579:Cytochrome Reductases / Q000097:blood; D042966:Cytochrome-B(5) Reductase; D015786:Cytochromes b5 / Q000097:blood; D004163:Diphosphoglyceric Acids / Q000494:pharmacology; D008862:Microsomes, Liver / Q000201:enzymology; D011817:Rabbits; D012156:Reticulocytes / Q000201:enzymology*; D012995:Solubility
D004163:Diphosphoglyceric Acids; D000255:Adenosine Triphosphate; D015786:Cytochromes b5; D003579:Cytochrome Reductases; D042966:Cytochrome-B(5) Reductase; D002402:Cathepsin D