Very general formation of tetrahydropterincation radicals during reaction of iron porphyrins with tetrahydropterins: model for the corresponding NO-synthase reaction

Abstract

Electron transfer from tetrahydropterins to iron porphyrins, with formation of intermediate tetrahydropterin cation radicals, is a very general reaction that was shown to occur not only with tetrahydrobiopterin, as originally found in NO-synthases, but also with another important biological cofactor, tetrahydrofolate, and various iron porphyrins, either in their ferric state, or in the Fe^IIO₂ state, as in the first model of the corresponding NO-synthase reaction described in this paper.