title: Characterization of two acid proteinases found in rabbit skin homografts.
abstract: Two types of acid proteinase activity found in rabbit skin homografts were characterized by studying the effect of temperature, pH and polyacrylamide-gel electrophoresis. Their chromatographic behaviour was characterized on DEAE-cellulose, Sephadex G-75, G-100 and G-200, and their molecular weights were estimated by gel filtration. One of the acid proteinases in the homograft resembled cathepsin D (EC 3.4.23.5) of normal skin. The other acid proteinase differed from cathepsin D with respect to heat inactivation, pH optimum and molecular weight; it was not inactivated on heating at 60 degrees C for 60 min, its pH optimum was 2.5 and its molecular weight measured by Sephadex G-100 chromatography was 100 000. In all these respects, the heat-stable proteinase resembles cathepsin E (EC 3.4.23.5) of rabbit polymorphonuclear leucocytes.
mesh_terms: D000818:Animals; D002403:Cathepsins / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D012867:Skin / Q000201:enzymology*; D016038:Skin Transplantation; D013696:Temperature; D014184:Transplantation, Homologous
chemical_list: D002403:Cathepsins; D010447:Peptide Hydrolases