A new type of low-molecular mass cysteine proteinase inhibitor from pig leukocytes.
A new low-molecular mass cysteine proteinase inhibitor (CPI) was purified from the cytosol of peripheral pig leukocytes. The isolation procedure included DEAE chromatography, Sephadex G-100 gel filtration and fast-protein liquid chromatography on Mono Q. The procedure resulted in the isolation of a homogeneous protein with a molecular mass of approximately 12 kDa and a pI of 4.8. The amino terminus is blocked. The amino-acid composition and the sequence of the C-terminal part of the molecule are suggestive of a new family of cystatins. The CPI was found to be a tight-binding inhibitor of both papain and cathepsin L, with Ki values of 0.1 nM and 1 nM, respectively.
Kopitar
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M
Odsek za biokemijo, Institut J. Stefan, Univerza E. Kardelja, Ljubljana, Jugoslavija.
Ritonja
A
A
Popovic
T
T
Gabrijelcic
D
D
Krizaj
I
I
Turk
V
V
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D002645:Chickens; D015853:Cysteine Proteinase Inhibitors / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D007962:Leukocytes / Q000032:analysis*; D008722:Methods; D008969:Molecular Sequence Data; D013552:Swine
D000596:Amino Acids; D015853:Cysteine Proteinase Inhibitors