title: Stem bromelain: amino acid sequence and implications for weak binding of cystatin.
abstract: The amino acid sequence of stem bromelain, the major cysteine proteinase from pineapple stem is described. It shows that the enzyme is a member of the papain superfamily of cysteine proteinases, but is not very closely related to any other known member of this group. The sequence shows mutation or deletion of several residues that have been conserved in cysteine proteinases examined previously, including Asn-175 (papain). We suggest that some of these changes have the effect of altering the active-site geometry of stem bromelain, and that this accounts for the resistance of the enzyme to inhibition by cystatins and E-64[L-3-carboxy-2,3-trans-epoxypropionylleucylamido(4-guanidino)b utane].
authors.affiliation: Department of Biochemistry, J. Stefan Institute, Ljubljana, Yugoslavia.
authors.forename: A
authors.initials: A
authors.lastname: Ritonja
authors.forename: A D
authors.initials: AD
authors.lastname: Rowan
authors.forename: D J
authors.initials: DJ
authors.lastname: Buttle
authors.forename: N D
authors.initials: ND
authors.lastname: Rawlings
authors.forename: V
authors.initials: V
authors.lastname: Turk
authors.forename: A J
authors.initials: AJ
authors.lastname: Barrett
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D001963:Bromelains / Q000037:antagonists & inhibitors / Q000378:metabolism*; D056655:Cathepsin H; D056668:Cathepsin L; D002403:Cathepsins; D003488:Cyanogen Bromide; D015891:Cystatins; D003546:Cysteine Endopeptidases; D010450:Endopeptidases; D005638:Fruit; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010206:Papain; D010446:Peptide Fragments; D010944:Plants / Q000201:enzymology*; D011480:Protease Inhibitors; D011506:Proteins / Q000378:metabolism* / Q000494:pharmacology; D012689:Sequence Homology, Nucleic Acid; D013329:Structure-Activity Relationship
chemical_list: D015891:Cystatins; D010446:Peptide Fragments; D011480:Protease Inhibitors; D011506:Proteins; C100158:cystatin, egg-white; D001963:Bromelains; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; C534126:CTSH protein, human; D056655:Cathepsin H; D010206:Papain; D007930:Leucine; D003488:Cyanogen Bromide; C024974:E 64