Group 14 amides oxidative addition/redox

Figure 3.8. Structures of vitamins or vitamin-derived molecules that function in oxidation-reduction reactions. The oxidation of these redox groups in the inner mitochondricil membrane contributes to the electron transport chain that carries electrons from the oxidation of glucose to oxygen and in the process pumps protons from one side to the other of the inner mitochondrial membrane (see Chapter 8 for details). The proton gradient thus formed is used to phosphorylate ADP to form 32 of the 36 ATPs resulting from the oxidation of one glucose molecule to six CO2 and six H2O molecules. A Vitamin B3, also called niacin or nicotinic acid, becomes converted to the amide (nicotinamide) and dressed up with a ribose sugar. Then, in a manner like that of riboflavin in B becomes phosphorylated to form nicotinamide mononucleotide (NMN) or further reacted with the addition of adenosine monophosphate (AMP) to form nicotinamide adenine dinucleotide (NAD). B Vitamin B2, also known as riboflavin, is shown converted to the forms involved in redox reactions such as those of the electron transport chain. (From Biochemistry, Second Edition, D. Voet and J. Voet, Copyright 1995, John Wiley Sons, New York. Reprinted with permission of John Wiley Sons, Inc.)...

Production of motion by the addition of electrons requires attachment of vitamin-like molecules such as B2 and B3 (see Chapters 3 and 5), because the natural amino acids do not easily take up and release electrons. In our experimental demonstration, an N-methyl nicotinamide was attached to a lysine residue by the amide moiety, and indeed reduction drove contraction. Furthermore, increasing the oil-like character on replacing Val (V) by Phe (F), as with Polymers XIII, IX, and X in Table 6.1, increases the affinity of an oxidized group for electrons, as discussed in Chapter 5 and represented in Figure 5.19C. In the circumstance of natural proteins, the reduction-oxidation (redox) vitamin-like molecules bind to oppositely charged sites by ion pairing and by oillike associations, as discussed below. 

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