Biological enzyme modeling biomimetics

The very important role of the heme system, Fe(Proto)LL ( 3) in biological oxygen transport and consumption as well as electron transport is a main topic not only of biochemists, but of bioinorganic chemists and biomimetic chemists as well for this general topic, the reader may consult some recent review articles [14-21,22]. Bioinorganic chemists have studied the effect of replacement of iron by other 3d metals, especially chromium, manganese, and cobalt, and frequently, interesting structural, spectral, or functional models [14,20] of the heme enzymes have been found with these metals. 

Biological and Biomimetic Catalysis of Manganese Redox Enzymes and Their Inorganic Models... 

The catalytic properties of Mn enzyme structural models are not limited to the natural substrates of the enzymes they mimic. One could classify this catalysis based upon the substrates as biological mimetic catalysis or biomimetic catalysis [175] and biologically inspired catalysis or bioinspired catalysis [176], Unlike biomimetic catalysis, its bioinspired counterpart capitalizes on nature s findings to change nonnatural substrates chemically and, perhaps, unravel novel chemistry. 

I have been pursuing enzyme mimics, artificial enzymes that perform biomimetic chemistry, since starting my independent career in 1956. In the first work [52-59] my co-workers and I studied models for the function of thiamine pyrophosphate 1 as a coenzyme in enzymes such as carboxylase. We discovered the mechanism by which it acts, by forming an anion 2 that we also described as a stabilized carbene, one of its resonance forms. We examined the related anions from imidazolium cations and oxazolium cations, which produce anions 3 and 4 that can also be described as nucleophilic carbenes. We were able to explain the structure-activity relationships in this series, and the reasons why the thiazolium ring is best suited to act as a biological... 

Wikaira, J., Gorun, S M. (1999) Biological and biomimetic catalysis of manganese redox enzymes and their inorganic models, in Reedijk, J. and Bouwman, E. (eds) Bioinorganic Catalysis (2nd Edition, Revised and Expanded) Marcel Dekker, Inc., New York, N. Y., pp. 355-422. 

---