Lanosterol 14α-demethylase:: Target of the antifungal drugs.

lanosterol 14 alpha-demethylase, the target enzyme of the azole antifungals, is the only known member of the P450 superfamily to be expressed in higher plant, fungi, and mammals. Amino acid sequences from higher plant, fungi and mammals have been characterized. Oxidative removal of the 14 alpha methyl group from lanosterol by the enzyme includes three steps and the free radicals are involved in the scheme of the catalytic reaction. The active site of lanosterol 14 alpha-demethylase appears to be open above heme prosthetic group pyrrole ring C. Pyrrole ring A, B and D are occluded by active site residues; 3 beta-hydroxyl group, Delta(8(9))-double bond and 17-side chain of the substrate lanosterol are the key functional groups for the correct enzyme-substrate interaction and high catalytic turnover. The discussion about the structure-activity relationship (SAR) of two series inhibitors of the enzyme, substrate analogues and azole antifungals? provides the better basis for further high potent inhibitors design.