The Guanidinium motif
Channel: thunderf00tCC
Date: 2012-05-03

The guanidinium motif crops up all over biochemistry.  Normally used as a solution of an aqueous salt to denature proteins, it very electronically similar to urea (another powerful denaturant).  The Guanidinium motif appears almost exactly in the side chain of the amino acid arginine, and also appears (albeit in neutral form and in a fused heterocycle) as a part of the base pair guanine, which helps stabilize the core of the double helix of DNA.

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