title: An amperometric enzyme electrode for the determination of 3alpha-hydroxysteroids.
abstract: An enzyme electrode for quantifying the total content of 3alpha-hydroxysteroids is described. 3alpha-Hydroxysteroid dehydrogenase (E.C. 1.1.1.50) was immobilized on the surface of glassy-carbon and low-temperature isotropic-carbon electrodes by intermolecular cross-linking with bovine serum albumin and glutaraldehyde. The effects of the following factors on the response to androsterone were studied: applied potential, the concentration and pH of the pyrophosphate buffer used, and the NAD concentration. The Michaelis-Menten constant for 3alpha-hydroxysteroid dehydrogenase in solution was determined amperometrically with androsterone as substrate (K(m) = 189muM). A preliminary report of the response of the system to serum samples containing a bile acid is presented.
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal, Quebec, Canada H3A 2K6.
authors.forename: M
authors.initials: M
authors.lastname: Teodorczyk
authors.forename: W C
authors.initials: WC
authors.lastname: Purdyt