title: Structure-function relationship of bromelain isoinhibitors from pineapple stem.
abstract: Bromelain isoinhibitors from pineapple stem (BIs) are unique double-chain inhibitors and inhibit the cysteine proteinase bromelain competitively. The three-dimensional structure was shown to be composed of two distinct domains, each of which is formed by a three-stranded anti-parallel beta-sheet. Unexpectedly, BIs were found to share similar folding and disulfide-bond connectivities not with the cystatin superfamily, but with Bowman-Birk trypsin/chymotrypsin inhibitor (BBI). The structural similarity between them suggests that BIs and BBI have evolved from a common ancestor and differentiated in function during the course of molecular evolution.
authors.affiliation: Department of Biological Sciences, Faculty of Engineering, Gunma University, Kiryu, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Hatano
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Sawano
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanokura
mesh_terms: D000595:Amino Acid Sequence; D031230:Ananas / Q000737:chemistry; D001665:Binding Sites; D001963:Bromelains / Q000037:antagonists & inhibitors*; D019143:Evolution, Molecular; D010940:Plant Proteins / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
chemical_list: D010940:Plant Proteins; D011480:Protease Inhibitors; D001963:Bromelains