Open AccessCharacterisation of Cathepsin B and Collagenolytic Cathepsin from Human Placenta
Author(s) -
EVANS Patricia,
ETHERINGTON David J.
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12071.x
Subject(s) - chemistry , cathepsin b , sephadex , biochemistry , cathepsin c , cathepsin l1 , cathepsin h , cathepsin o , cathepsin , sepharose , antipain , cathepsin a , enzyme , leupeptin , protease
1. Human placental cathepsin B and collagenolytic cathepsin were separated by chromatography on columns of Amberlite CG‐50. Collagenolytic cathepsin was partially purified by chromatography on DEAE‐Sephadex (A‐50) and Sephadex G‐100. Cathepsin B was purified by chromatography on CM‐cellulose and Sephadex G‐100. 2. Both enzymes required activation by thiol compounds and were bound to organomercurial‐Sepharose‐4B. Sulphydryl‐blocking reagents were inhibitory, which confirmed an essential thiol group to be present. 3. The enzymes degraded soluble calf skin collagen and insoluble bovine tendon collagen in the telopeptide region at pH 3.5 and 28 °C to yield mainly α‐chain components. 4. In contrast to cathepsin B, collagenolytic cathepsin was found not to hydrolyse any of the low‐molecular‐weight synthetic substrates that were tested. 5. Leupeptin, a structural analogue of arginine‐containing synthetic substrates, and antipain. an inhibitor of papain, were strongly inhibitory to both enzymes. 6. The isoelectric points of the enzymes were similar. being 5.4 for cathepsin B and 5.1 for collagenolytic cathepsin. 7. From chromatography on Sephadex G‐100 the molecular weight of cathepsin B was calculated to be 24500 and that of collagenolytic cathepsin to be 34600.