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The primary structure of inhibitor of cysteine proteinases from potato
Author(s) -
Kriz̆aj I.,
Drobnic̆-Kos̆orok M.,
Brzin J.,
Jerala R.,
Turk V.
Publication year - 1993
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(93)80366-3
Subject(s) - cysteine , biochemistry , trypsin , peptide sequence , protein primary structure , trypsin inhibitor , serine , kunitz sti protease inhibitor , cysteine proteinase inhibitors , proteinase inhibitor , chemistry , serine proteinase inhibitors , amino acid , homology (biology) , biology , enzyme , serine protease , gene , protease , apoptosis , programmed cell death , caspase
The complete amino acid sequence of the cysteine proteinase inhibitor from potato tubers was determined. The inhibitor is a single‐chain protein having 180 amino acid residues. Its primary structure was elucidated by automatic degradation of the intact protein and sequence analysis of peptides generated by CNBr, trypsin and glycyl endopeptidase. A search through the protein sequence database showed homology to other plant proteinase inhibitors of different specificities and non‐inhibitory proteins of M r around 20,000. On the basis of sequence homology, prediction of secondary structure and fold compatibility, based on a 3D‐1D score to the three‐dimensional profile of Erythrina caffra trypsin inhibitor, we suggest that the potato cysteine proteinase inhibitor belongs to the superfamily of proteins that have the same pattern of three‐dimensional structure as soybean trypsin inhibitor. This superfamily would therefore include proteins that inhibit three different classes of proteinases ‐ serine, cysteine and aspartic proteinases.