Département de chimie moléculaire

The immobilization of nitrate reductase (NR) was performed by entrapment in a laponite clay gel and crosslinking by glutaraldehyde. In presence of nitrate and Me viologen, a catalytic current appeared at - 0.60 V illustrating the enzymic redn. of nitrate into nitrite via the reduced form of the freely diffusing Me viologen. The electropolymn. of a water-sol. pyrrole viologen deriv. within the interlamellar spaces and channels of the host clay matrix successfully carried out the elec. wiring of the entrapped NR. Rotating disk measurements led to the detn. of kinetic consts., namely k 2 = 10.7 s- 1 and K M = 7 $μ$M. These parameters reflect the efficiency of the electro-enzymic redn. of nitrate and the substrate affinity for the immobilized enzyme. [on SciFinder(R)]