Purification and properties of two protease inhibitors from rat skin inhibiting papain and other SH-proteases.
Two papain inhibitors, I1 and I2, from rat skin extract were purified by affinity chromatography on KSCN-modified papain-agarose gel and by gel filtration on Sephadex G-100. I1 had a molecular weight of 74 000, a pI of 4.6, and it contained 4% of carbohydrates. I1 inhibited papain, ficin, bromelain, rat skin benzoylarginine-2-naphthylamide hydrolase, and to a minor extent, rat skin cathepsin C and bovine trypsin. Bovine chymotrypsin or rat skin cathepsin D were not inhibited and benzoylarginine-2-naphthylamide hydrolase was inhibited only at alkaline pH. An inhibitor corresponding to I1 was present in various rat tissues and also in serum. A similar inhibitor was present in the skin of cat, rabbit, guinea pig, and man. I2 had a molecular weight of 13 400, a pI of 4.9 and it contained no carbohydrates. I2 inhibited all thiol proteases tested, but not trypsin, chymotrypsin, or rat skin cathepsin D. I2 formed an equimolar complex with papain and benzoylarginine-2-naphthylamide hydrolase. I2 was present in rat skin, muscle, lung, and small intestine, but not in kidney, liver, or serum. A similar inhibitor was found in skin extracts of cat, rabbit, guinea pig, and man.
D000818:Animals; D001963:Bromelains / Q000037:antagonists & inhibitors; D002403:Cathepsins / Q000037:antagonists & inhibitors; D002415:Cats; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D005361:Ficain / Q000037:antagonists & inhibitors; D006168:Guinea Pigs; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010206:Papain / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors; D011817:Rabbits; D051381:Rats; D012867:Skin / Q000032:analysis*; D014361:Trypsin Inhibitors / Q000032:analysis
D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D001963:Bromelains; D002403:Cathepsins; D002918:Chymotrypsin; D010206:Papain; D005361:Ficain