Poly-ε-lysine amylase conjugates to increase the stability of enzyme

Poly-ε-lysine (ε-PL), an unusual naturally occurring homopolyamide of L-lysine having linkage between ε-amino and α-carboxyl groups, is biodegradable, edible and non-toxic towards human and environment. The conjugate of ε-PL with amylase was successfully prepared by ionic interaction. The ε-PL-amylase conjugate showed better temperature and pH stability than native enzyme. The degradation of enzyme by temperature and pH followed first order degradation kinetics. The k value (reaction constant), D value (decimal reduction time) and activation energy confirmed the better temperature stability of conjugated enzymes than native enzyme. The km and Vmax values were found to be similar for both conjugated and native enzyme suggesting, no change in enzyme configuration which alters the substrate binding.