A heterogeneous kinetic model for the cutinase-catalyzed hydrolysis of cyclo-tris-ethylene terephthalate

The kinetics of enzyme-catalyzed hydrolysis of the polyester oligomer cyclo-tris-ethylene terephthalate, commonly known as cyclic trimer, using a developmental cutinase is reported. The effect of substrate surface area and enzyme concentration, in a largely aqueous medium, on the rate of hydrolysis was measured via spectrophotometric measurement using high performance liquid chromatography (lambda 254 nm) at 60 degrees C in a glycine buffer (pH 8). The rate was strongly dependent on the substrate's surface characteristics. When the substrate surface area was relatively small and the substrate was relatively low in crystallinity, the reaction followed zero order kinetics, whereas a first order rate constant was obtained when the substrate surface area was increased considerably and the crystallinity was relatively high.