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Inhibition of cysteine proteinases by a protein inhibitor from potato
Author(s) -
Rowan Andrew D.,
Brzin Joze,
Buttle David J.,
Barrett Alan J.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)81186-r
Subject(s) - cystatin , biochemistry , cysteine , proteinase inhibitor , cysteine proteinase inhibitors , bromelain , chemistry , proteolysis , enzyme , exopeptidase , cystatin c , papain , apoptosis , programmed cell death , renal function , caspase
The inhibitory specificity of a protein from potato tubers that inhibits cysteine proteinases (potato cysteine proteinase inhibitor, PCPI) has been compared with that of chicken egg‐white cystatin. Most proteinases that are inhibited by cystatin were also inhibited by PCPI, but the potato inhibitor inhibited stem bromelain and fruit bromelain, which are not inhibited by cystatin, and for which no protein inhibitor of comparable potency has previously been described. In contrast, papaya proteinase IV was unaffected by PCPI as it is by the cystatins, and the exopeptidase, dipeptidyl peptidase I, is inhibited by cystatins, but was unaffected by PCPI. The differences in inhibitory specificity between these proteins may well reflect differences between superfamilies of cysteine proteinase inhibitors.