title: Characterization of a Kunitz trypsin inhibitor with one disulfide bridge purified from Swartzia pickellii.
abstract: Swartzia pickellii is a Leguminosae that belongs to the Caesalpinioideae sub-family the Swartzia pickellii Trypsin Inhibitor (SWTI), a serine proteinase inhibitor was isolated from its seeds. SWTI is a single polypeptide chain protein and it's structure has 174 amino acid residues, it homologous to other Kunitz plant inhibitors, however shows some major differences: it contains only one disulfide bridge, instead two which are usually found in plant Kunitz inhibitors, and the SWTI reactive site does not contain the usual Arg or Lys residues at the putative reactive site (position 65). A glycosylation site was detected at Asn38 with 1188 kDa carbohydrate portion. The primary structure micro heterogeneity was found combining the sequence determination and mass spectrometry. Three forms of SWTI were actually defined: two glycosylated forms a 20,204 kDa (Arg 165) and 20,185 kDa (His 165) and one deglycosylated form 19,016 kDa (Arg 165), all of them contain a Met residue at position 130.
authors.affiliation: Departamento de Bioquímica, Universidade de Pernambuco, Recife, PE, Brazil.
authors.forename: Maria
authors.initials: M
authors.lastname: do Socorro M  Cavalcanti
authors.forename: Maria Luiza V
authors.initials: ML
authors.lastname: Oliva
authors.forename: Hans
authors.initials: H
authors.lastname: Fritz
authors.forename: Marianne
authors.initials: M
authors.lastname: Jochum
authors.forename: Reinhardt
authors.initials: R
authors.lastname: Mentele
authors.forename: Misako
authors.initials: M
authors.lastname: Sampaio
authors.forename: Luana C B B
authors.initials: LC
authors.lastname: Coelho
authors.forename: Isabel F C
authors.initials: IF
authors.lastname: Batista
authors.forename: Claudio A M
authors.initials: CA
authors.lastname: Sampaio
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D004220:Disulfides / Q000737:chemistry; D007887:Fabaceae / Q000737:chemistry*; D006031:Glycosylation; D007527:Isoenzymes / Q000032:analysis; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D004220:Disulfides; D007527:Isoenzymes; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean