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
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