Allosteric Enzyme-Based Biosensors-Kinetic Behaviours of Immobilised L-Lysine-α-Oxidase from : pH Influence and Allosteric Properties.

The present study describes the kinetics of L-lysine-α-oxidase (LO) from immobilised by co-crosslinking onto the surface of a Pt electrode. The resulting amperometric biosensor was able to analyse L-lysine, thus permitting a simple but thorough study of the kinetics of the immobilised enzyme. The kinetic study evidenced that LO behaves in an allosteric fashion and that cooperativity is strongly pH-dependent.

A novel approach for the selective analysis of l-lysine in untreated human serum by a co-crosslinked l-lysine-α-oxidase/overoxidized polypyrrole bilayer based amperometric biosensor.

An amperometric biosensor based on an l-lysine-α-oxidase (LO) layer immobilized by co-crosslinking onto the surface of an overoxidized polypyrrole modified Pt electrode (Pt/oPPy) and able to analyse l-lysine (Lys) in untreated human serum is described. The sensing electrode has been characterised and a proper enzyme kinetics optimisation permits to use a low specific enzyme as LO from Trichoderma viride for the selective biorecognition of Lys in the presence of other interferent amino acids; a kinetics study of LO evidenced also the allosteric behaviour of this enzyme, a kinetic feature which was never reported before for this enzyme. The biosensor showed a sensitivity of 0.