G is for Glycine. Glycine is the simplest proteinogenic amino acid and the simplest stable amino acid. It has no side chain (having only a hydrogen where the side chain would be). It is encoded by all the codons that start with GG (GGA, GGC, GGG, and GGU). How synchronistic that G is for Glycine and G is also for Guanine, the only nucleotide of the first two positions of the codons encoding Glycine. The absence of a side chain makes Glycine the only achiral proteinogenic amino acid, with all others having L-chirality.
Glycine was named by the Swedish chemist Berzelius, who discovered the element selenium (in 1817) and also cerium (in 1803). He also discovered how to isolate silicon in 1824, which the entire computer chip industry is dependent upon for silicon wafers. He coined the term “protein” in 1838, meaning “of the first rank”, because proteins were fundamental to living organisms. Berzelius also developed a system of chemical notation (e.g. H2O, FE2O3) still used today with the only difference being that Berzelius used superscripts instead of subscripts.
Glycine makes up a third of collagen, which is the main structural protein the the extracellular matrix in various connective tissues. Collagen is the most abundant protein in mammals, making up 1/4th to 1/3rd of the whole-body protein content.
Glycine is also an inhibitory neurotransmitter in the central nervous system.
The best food sources for Glycine are red meat, seeds, turkey, chicken, pork, peanuts, caned salmon, granola, quinoa, hard cheese, pasta, soybeans, bread, almonds, eggs, and beans. Also, Gelatin being cooked collagen, it is quite high in Glycine.
It’s now time for some Glycine here at Café Crème…