title: Identification and characterization of a Bowman-Birk inhibitor active towards trypsin but not chymotrypsin in Lupinus albus seeds.
abstract: The paper describes the purification, structural characterization and inhibitory properties of a trypsin inhibitor from Lupinus albus L., a leguminous plant believed to be devoid of any protease inhibitor. The protein has been isolated by a newly set-up procedure and characterized by direct amino acid sequencing, MALDI-TOF mass spectroscopy and circular dichroism. Inhibitory properties toward bovine trypsin and chymotrypsin, as well as its thermal and pH stabilities, have been also assessed. The inhibitor is 63 amino acid long (Mr 6858; pI 8.22) and it is capable to inhibit two trypsin molecules simultaneously, with a Kd of 4.2+/-0.4 nM, but not chymotrypsin. BLAST search against UniProtKB/TrEMBL database indicates that the inhibitor belongs to the Bowman-Birk inhibitor (BBI) family. The interest in these serine-protease inhibitors arises from the ability to prevent or suppress carcinogen-induced transformation, as shown in various in vitro and in vivo model systems.
authors.affiliation: Department of Agri-Food Molecular Sciences, State University of Milan, via G. Celoria 2, 20133 Milano, Italy. alessio.scarafoni@unimi.it
authors.forename: Alessio
authors.initials: A
authors.lastname: Scarafoni
authors.forename: Alessandro
authors.initials: A
authors.lastname: Consonni
authors.forename: Valerio
authors.initials: V
authors.lastname: Galbusera
authors.forename: Armando
authors.initials: A
authors.lastname: Negri
authors.forename: Gabriella
authors.initials: G
authors.lastname: Tedeschi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rasmussen
authors.forename: Chiara
authors.initials: C
authors.lastname: Magni
authors.forename: Marcello
authors.initials: M
authors.lastname: Duranti
mesh_terms: D000595:Amino Acid Sequence; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D031297:Lupinus / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D017186:Titrimetry; D014357:Trypsin / Q000378:metabolism*; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D002918:Chymotrypsin; D014357:Trypsin