Glycylglycine

Glycylglycine, also called diglycine, is the dipeptide formed from two glycine residues linked by a single peptide bond. Its chemical formula is C4H8N2O3 and its molecular weight is about 132.12 g/mol. The structural formula is H2N-CH2-CO-NH-CH2-COOH, reflecting an amino terminus on one end and a carboxyl terminus on the other.

Glycylglycine can be produced through proteolytic digestion of proteins or synthesized by standard peptide synthesis methods. It is a small, highly soluble molecule in water and serves as a convenient model compound in peptide chemistry and biochemistry.

In solution, glycylglycine behaves as a zwitterion near physiological pH, with the amino group typically protonated and the carboxyl group deprotonated, yielding a net zero charge. Like other dipeptides, its ionization state and solubility are pH-dependent, influencing its behavior in biochemical assays and analytical procedures.

Applications of glycylglycine include use as a model substrate for studying peptide bond hydrolysis and protease activity, and as a reference compound in various chromatographic and spectroscopic analyses. It also serves as a building block in peptide synthesis for research and methodological development.

Safety and handling are consistent with other small amide-containing dipeptides. Glycylglycine is generally regarded as a routine laboratory chemical, to be handled according to standard safety guidelines.

See also: glycine, peptides, diglycine.