Cysteine proteinase inhibitors from rabbit skeletal muscle.
1. Two cysteine proteinase inhibitors, I-T (Mr = 29,000) and I-S (Mr = 10,700), were isolated from rabbit skeletal muscle by means of succesive extraction with a neutral buffer solution, precipitation at pH 3.7, acetone fractionation and gel permeation on Sephadex G-75. 2. I-T is a formed trimer of a monomeric inhibitor, I-M (Mr = 10,500), through disulfide bonds. 3. I-S is almost completely stable between pH 3 and 8, while I-M is unstable in the same pH range. 4. I-M acts most effectively towards cathepsins H and L, showing moderate activity towards cathepsin B and only weak activity towards papain. I-S acts most effectively towards cathepsin L, followed by, in decreasing order, cathepsin H, cathepsin B and papain.
Matsuishi
M
M
Department of Food Science and Technology, Nippon Veterinary and Zootechnical College, Japan.
Okitani
A
A
Hayakawa
Y
Y
Kato
H
H
D000818:Animals; D002403:Cathepsins / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D011817:Rabbits
D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D002403:Cathepsins