KINETIC-STUDY ON THE IRREVERSIBLE THERMAL-DENATURATION OF LENTIL LECTIN

The irreversible thermal denaturation of lentil lectin was investigate d at pH 7.4 using different techniques including high-sensitivity diff erential scanning calorimetry, differential detergent solubility therm al gel analysis, intrinsic fluorescence and hemagglutinating activity assays. The shape of the transition, as well as its scan-rate dependen ce, can be explained by assuming that thermal denaturation takes place according to the kinetic scheme N (k)--> D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhen ius equation, N the native state, and D the denatured one. On the basi s of this model, the value of the rate constant as a function of tempe rature and the activation energy were calculated. The analytical data obtained with the other methods used in this work support the proposed two-state kinetic model.