Kinetics of interaction of trypsin with an anionic inhibitor of trypsin BWI-1a from buckwheat seeds

Biochemistry (Mosc). 1999 Oct;64(10):1104-7.

Abstract

The kinetics of binding of bovine trypsin to a proteinaceous inhibitor of trypsin from buckwheat seeds (BWI-1a) has been studied. The association rate constant (k(ass)) was 2.2 x 10(6) M-1 x sec-1 and the dissociation rate constant (k(off)) of the enzyme--inhibitor complex was 3.5 x 10(-3) sec-1; the inhibition constant Ki was 1.5 nM. The inhibitor BWI-1a is of the slow, tightly binding type. The mechanism of the inhibition of bovine trypsin by the trypsin inhibitor BWI-1a was studied. The mechanism of inhibition was found to involve two steps according to the kinetic data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anions
  • Cattle
  • Fagopyrum / metabolism*
  • Kinetics
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism*
  • Trypsin / metabolism*
  • Trypsin Inhibitors / isolation & purification
  • Trypsin Inhibitors / metabolism*

Substances

  • Anions
  • BWI-1 protein, Fagopyrum esculentum
  • Plant Proteins
  • Trypsin Inhibitors
  • Trypsin