Glycine

 General Features:

 

Glycine Facts

Abbreviated: Gly or G

Molecular Formula: C₂H₅NO₂

pKa: 2.3 (-COOH), 9.6 (α-NH2)

Physiological Roles:

• In Gram-positive bacteria, the double-glycine (GG) motif plays a key role in many peptide secretion systems involved in quorum sensing and bacteriocin production. (http://mic.sgmjournals.org/content/150/5/1121.full)

• It is unique among the amino acids in that it does not contain a chiral center. It can fit into hydrophilic or hydrophobic environments since it contains the two hydrogen atoms in its side chain.

Synthesis:

Gylcine Synthesis

Synthesis of serine and glycine starts with oxidation of 3-phosphoglycerate in a dehydrogenase reasction forming 3-phospho pyruvate and NADH. A transamination reaction with glutamate forms 3-phospho-L-serine. Removal of the phosphate with H2O and Mg2+ yields serine. Glycine is generated by removal of the methyl group from serine by Serine hydroxylmethyl transferase.