title: Trypsin inhibitor from Dimorphandra mollis seeds: purification and properties.
abstract: A trypsin inhibitor from Dimorphandra mollis seeds was isolated to apparent homogeneity by a combination of ammonium sulfate precipitation, gel filtration, ion-exchange and affinity chromatographic techniques. SDS-PAGE analysis gave an apparent molecular weight of 20 kDa, and isoelectric focusing analysis demonstrated the presence of three isoforms. The partial N-terminal amino acid sequence of the purified protein showed a high degree of homology with various members of the Kunitz family of inhibitors. This inhibitor, which inhibited trypsin activity with a Ki of 5.3 x 10(-10) M, is formed by a single polypeptide chain with an arginine residue in the reactive site.
authors.affiliation: Departamento de Ciências Naturais, Universidade Federal de Mato Grosso do Sul, Três Lagoas, Brazil. bioplant@bestway.com.br
authors.forename: M L
authors.initials: ML
authors.lastname: Macedo
authors.forename: D G
authors.initials: DG
authors.lastname: de Matos
authors.forename: O L
authors.initials: OL
authors.lastname: Machado
authors.forename: S
authors.initials: S
authors.lastname: Marangoni
authors.forename: J C
authors.initials: JC
authors.lastname: Novello
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D007887:Fabaceae / Q000737:chemistry*; D006868:Hydrolysis; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification*; D010946:Plants, Medicinal; D012639:Seeds / Q000737:chemistry*; D020539:Sequence Analysis, Protein; D014357:Trypsin / Q000737:chemistry; D014361:Trypsin Inhibitors; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D000516:alpha-Amylases; D002918:Chymotrypsin; D014357:Trypsin