IMMOBILIZATION OF ENZYMES ON LIPID BILAYERS ON A METAL-SUPPORT ALLOWSSTUDY OF THE BIOPHYSICAL MECHANISMS OF ENZYMATIC-REACTIONS

We developed a glucose minisensor based on immobilization of the avidi n-glucose oxidase (A-GOX) complex on biotinylated bilayer lipid membra nes formed on a metal support (s-BLM). The immobilization of the A-GOX complex on a lipid bilayer was controlled by means of the electrostri ction method which allows us to determine the changes in membrane capa citance C, the elasticity modulus in the direction perpendicular to th e s-BLM surface E(perpendicular to), and the trans-membrane potential Delta phi(m). The binding of the A-GOX complex to the s-BLM resulted i n a decrease in C, increase in E(perpendicular to) and increase in Del ta phi(m), suggesting that A-GOX represents a negatively charged compl ex which increases membrane ordering. Using the simple amperometric me thod we studied glucose oxidation by GOX and determined several import ant constants of the enzymatic reaction.