Scope and limitation of single electron transfer in biology.

This article is thought to be a supplement to an earlier one "Mechanism of Hydrogen Transfer in Redox Enzymes"33). Most of the basic concepts and hypotheses put forward then, are still valid. Substantial new evidence supporting our views has been advanced since then. The new data presented here concern modified or as we call them "mutilated flavins", namely 5-deaza- and 5-thiaflavin, which upon incorporation into apoflavoprotein retain some, but not all of the activities encountered with the native flavoproteins. [ABSTRACT FROM AUTHOR]