title: Purification and pH stability characterization of a chymotrypsin inhibitor from Schizolobium parahyba seeds.
abstract: Schizolobium parahyba chymotrypsin inhibitor (SPCI) was completely purified as a single polypeptide chain with two disulfide bonds, by TCA precipitation and ion exchange chromatography. This purification method is faster and more efficient than that previously reported: SPCI is stable from pH 2 to 12 at 25 degrees C, and is highly specific for chymotrypsin at pH 7-12. It weakly inhibits elastase and has no significant inhibitory effect against trypsin and alpha-amylase. SPCI is a thermostable protein and resists thermolysin digestion up to 70 degrees C.
authors.affiliation: Universidade de Brasília, Depto de Biologia Celular, Laboratório de Biofísica, Campus Universitário Darcy Ribeiro, Asa norte. 70910-900, Brasília, DF, Brazil.
authors.forename: Rozeni C L
authors.initials: RC
authors.lastname: Teles
authors.forename: Elizabeth M T
authors.initials: EM
authors.lastname: de Souza
authors.forename: Leonardo de A
authors.initials: Lde A
authors.lastname: Calderon
authors.forename: Sonia M
authors.initials: SM
authors.lastname: de Freitas
mesh_terms: D002852:Chromatography, Ion Exchange / Q000379:methods; D002918:Chymotrypsin / Q000037:antagonists & inhibitors*; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D019685:Rosales / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D013820:Thermolysin / Q000378:metabolism
chemical_list: C096591:Chymotrypsin inhibitor protein, Schizolobium parahybum; D010940:Plant Proteins; D015842:Serine Proteinase Inhibitors; D002918:Chymotrypsin; D013820:Thermolysin