Two distinct species of corn cystatin in corn kernels

Besides corn cystatin I (CC-I) we found, by cloning, another molecular species of cystatin, named corn cystatin II (CC-II), which was found by screening with CC-I cDNA as a probe. The dissimilarity in amino acid sequence between CC-I and CC-II was distinct around the N-terminal region. Enzymologically, CC-II protein expressed in Escherichia coli was a stronger inhibitor of cathepsin L than CC-I.