Arginine sidechains

Guanidine (arginine sidechain) Methyl groups (nonacidic) Methyl groups CH X (CH-acidic, e.g., acetyl-CoA) + CO,... 

Figure 56. Formation of like-charged ion" pairs illustrated by the solvation of two arginine sidechains in lysozyme (Arg-61, leftmost residue, and Arg-73). Stereo plots show (a) the "un-solvated structure at t = 0.0 ps (b) the initial formation of the water-bridged structure at t = 8.25 ps (c) and (d) the fully "solvated water-bridged structures fort = 16.5 ps and t = 33.0 ps, respectively. The protein-solvent hydrogen bonds are shown as dotted lines.

Methylation of lysine or arginine sidechains is accomplished by Sn2 transfer of a methyl group from 5-adenosylmethionine (SAM) to nucleophilic lysine/ arginine sidechains (Figure 5.12b). The mechanism of deprotonation of the lysine sidechains has not yet been elucidated fully however, a combination of... 

Amino acids have two functional groups, the carboxylic group and the amino group, which can be converted to surfactant with a reactive molecule bearing a hydrophobic chain. Amino acids with reactive sidechains, such as lysine, arginine, aspartic acid, and glutamic acid, offer opportunities for the molecular design of AAS. 

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