title: A proteinase inhibitor from Caesalpinia echinata (pau-brasil) seeds for plasma kallikrein, plasmin and factor XIIa.
abstract: Caesalpinia echinata is a tree belonging to the Leguminosae family. The red color of the trunk, looking like burning wood ('brasa' in Portuguese), is the origin of the name Brazil. Seeds of leguminous plants contain high amounts of serine proteinase inhibitors that can affect different biological processes. Here we show that a protein isolated from seeds of C. echinata is able to inhibit enzymes that participate in blood coagulation and fibrinolysis. This inhibitor (CeKI) was purified to homogeneity by ion exchange and reversed-phase chromatography. SDS-PAGE indicated a single polypeptide chain with a molecular mass of 20 kDa. CeKI inhibits human plasma kallikrein ( K i =3.1 nM), plasmin ( K i =0.18 nM), factor XIIa ( K i =0.18 nM), trypsin ( K i =21.5 nM) and factor Xa ( K i =0.49 mM). CeKI inhibited kinin release from highmolecular- mass kininogen by kallikrein in vitro . The N-terminal sequence, determined by automatic Edman degradation, identified the inhibitor as a member of the Kunitz family. The secondary structure, determined by circular dichroism, is mainly a random coil followed by beta-sheet structure. The action of CeKI on enzymes of the blood-clotting intrinsic pathway was confirmed by prolongation of the activated partial thromboplastin time.
authors.affiliation: Departamento de Bioquimica, Universidade Federal de São Paulo, 04044-020 São Paulo, SP, Brazil.
authors.forename: Ilana
authors.initials: I
authors.lastname: Cruz-Silva
authors.forename: Andrezza J
authors.initials: AJ
authors.lastname: Gozzo
authors.forename: Viviane A
authors.initials: VA
authors.lastname: Nunes
authors.forename: Adriana K
authors.initials: AK
authors.lastname: Carmona
authors.forename: Adelaide
authors.initials: A
authors.lastname: Faljoni-Alario
authors.forename: Maria Luiza V
authors.initials: ML
authors.lastname: Oliva
authors.forename: Misako U
authors.initials: MU
authors.lastname: Sampaio
authors.forename: Claudio A M
authors.initials: CA
authors.lastname: Sampaio
authors.forename: Mariana S
authors.initials: MS
authors.lastname: Araujo
mesh_terms: D000595:Amino Acid Sequence; D029911:Caesalpinia / Q000737:chemistry* / Q000196:embryology; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D015956:Factor XIIa / Q000037:antagonists & inhibitors*; D005341:Fibrinolysin / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D020842:Plasma Kallikrein / Q000037:antagonists & inhibitors*; D012639:Seeds / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D015842:Serine Proteinase Inhibitors; D020842:Plasma Kallikrein; D015956:Factor XIIa; D005341:Fibrinolysin