Isolation and properties of a Kunitz-type protein inhibitor obtained from Pithecellobium dulce seeds


Por: Delgado-Vargas F., López-Valdés H.E., Valdés-Rodríguez S., Blanco-Labra A., Chagolla-López A., López-Valenzuela E.D.J.

Publicada: 1 ene 2004
Resumen:
We report for the first time the isolation and characterization of a protease inhibitor from the seeds of Pithecellobium dulce, which is a Leguminosae tree native to Mexico. The purification of the P. dulce trypsin inhibitor (PDTI) was a direct process. After its extraction (pH 8.0) and precipitation (80% (NH4)2SO4), the pH was adjusted to 4.0, the supernatant was loaded onto a CM-Sepharose column, and a single peak of trypsin inhibitory activity was eluted (CM-TIA). The main component of CM-TIA was PDTI, a protein composed of two polypeptide chains joined by disulfide bridge(s), with a pl of 4.95 and a molecular weight determined by electrospray mass spectrometry of 19 614 Da. The N-terminal sequence of PDTI has the highest similarity with the seed inhibitor of Acacia confusa. PDTI lacks chymotrypsin inhibitory activity. A low rate of cytotoxicity of CM-TIA toward RINmSF cells contrasted with a high rate of the active fraction G75-TIA (gel filtration chromatography; LC50 of 0.04 mg/mL).

Filiaciones:
Delgado-Vargas F.:
 Food Science and Technology Program, Fac. of Chem. and Biol. Sciences, Autonomous University of Sinaloa, Sinaloa, Mexico

López-Valdés H.E.:
 Institute for Neurobiology, UNAM, Queretaro, Qro., Mexico

Valdés-Rodríguez S.:
 CINVESTAV-IPN, Unidad Irapuato, Irapuato, Gto., Mexico

Blanco-Labra A.:
 CINVESTAV-IPN, Unidad Irapuato, Irapuato, Gto., Mexico

Chagolla-López A.:
 CINVESTAV-IPN, Unidad Irapuato, Irapuato, Gto., Mexico

López-Valenzuela E.D.J.:
 Food Science and Technology Program, Fac. of Chem. and Biol. Sciences, Autonomous University of Sinaloa, Sinaloa, Mexico
ISSN: 00218561
Editorial
American Chemical Society, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, Estados Unidos America
Tipo de documento: Article
Volumen: 52 Número: 20
Páginas: 6115-6121
WOS Id: 000224212000011
ID de PubMed: 15453675