Journal of Protein Chemistry

, Volume 20, Issue 8, pp 625–632

Purification and Characterization of a New Trypsin Inhibitor from Dimorphandra mollis Seeds

Authors

  • Gláucia C. Mello
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
  • Maria Luiza V. Oliva
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
  • Joana T. Sumikawa
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
  • Olga L. T. Machado
    • Centro de Biociências e BiotecnologiaUniversidade Estadual do Norte Fluminense
  • Sérgio Marangoni
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
  • José C. Novello
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
    • Departamento de Bioquímica, Instituto de BiologiaUniversidade Estadual de Campinas (UNICAMP)
Article

DOI: 10.1023/A:1013764118579

Cite this article as:
Mello, G.C., Oliva, M.L.V., Sumikawa, J.T. et al. J Protein Chem (2001) 20: 625. doi:10.1023/A:1013764118579

Abstract

A second trypsin inhibitor (DMTI-II) was purified from the seed of Dimorphandra mollis (Leguminosae-Mimosoideae) by ammonium sulfate precipitation (30–60%), gel filtration, and ion-exchange and affinity chromatography. A molecular weight of 23 kDa was estimated by gel filtration on a Superdex 75 column SDS-PAGE under reduced conditions showed that DMTI-II consisted of a single polypeptide chain, although isoelectric focusing revealed the presence of three isoforms. The dissociation constant of 1.7 × 10−9 M with bovine trypsin indicated a high affinity between the inhibitor and this enzyme. The inhibitory activity was stable over a wide pH range and in the presence of DTT. The N-terminal sequence of DMTI-II showed a high degree of homology with other Kunitz-type inhibitors.

Dimorphandra mollisMimosoideaetrypsin inhibitorN-terminal sequenceKunitz family

Copyright information

© Plenum Publishing Corporation 2001