Open AccessCorn Kernel cysteine proteinase inhibitor as a novel cystatin superfamily member of plant origin
Author(s) -
ABE Makoto,
ABE Keiko,
KURODA Masaharu,
ARAI Soichi
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb17365.x
Subject(s) - cystatin , complementary dna , papain , microbiology and biotechnology , cdna library , peptide sequence , biology , cysteine proteinase inhibitors , vigna , cysteine , amino acid , cysteine protease , signal peptide , cystatin c , biochemistry , gene , botany , enzyme , programmed cell death , renal function , caspase , apoptosis
A full‐length cDNA clone for a cysteine proteinase inhibitor (cystatin) was isolated from a λgt10 cDNA library of immature corn kernels by screening with a mixture of cDNA inserts for oryzacystatins I and II. The cDNA clone spans 960 base pairs, encoding a 135‐amino‐acid protein containing a signal peptide fragment. The protein, named corn cystatin I, is considered to be a member of the cystatin superfamily, since it contains the commonly conserved Gln‐Val‐Val‐Ala‐Gly region that exists in most known cystatins as a probable binding site and is significantly similar to other cystatins in its overall amino acid sequence. Corn cystatin I expressed in Escherichia coli showed a strong papain‐inhibitory activity. Northern blot analysis showed that the amount of mRNA for corn cystatin I reaches a maximum 2 weeks after flowering and then decreases gradually.