buffer,ph 6.0. The plates were assessed for a decrease in absorbance at 450 nm over 30 min on a Spectra Max 190 plate reader at 25°c,and specific rates were calculated from the initial linear portion of the curve.Pseudo Michaelis-Menten kinetics were assessed at four different substrate concentrations (50,100,200,and400) with 14 nM enzymes in 100 mM