CHARACTERIZATION OF PHYTANOYL COENZYME-A HYDROXYLASE IN HUMAN LIVER AND ACTIVITY MEASUREMENTS IN PATIENTS WITH PEROXISOMAL DISORDERS

Phytanoyl-Coenzyme A hydroxylase is a newly recognized peroxisomal enz yme which catalyses the first step in the alpha-oxidation of phytanoyl -Coenzyme A. Since measurement of this enzyme activity in human liver homogenate is of great importance especially in relation to inherited diseases in which this enzyme activity is deficient, we have studied i ts characteristics in human liver. The results described in this paper show that optimal activity measurements require preformed phytanoyl-C oenzyme A plus 2-oxoglutarate, Fe2+ and ascorbate. The conditions deve loped can be used to determine phytanoyl-Coenzyme A hydroxylase activi ty in human liver homogenates which is of utmost importance not only f or the diagnosis of patients, but also for the purification of the enz yme from various sources. (C) 1998 Elsevier Science B.V.