The molecule is an L-alpha-amino acid zwitterion that is the dizwitterionic form of epsilon-(gamma-glutamyl)lysine obtained by migration of protons from both carboxy groups to the amino groups; major species at pH 7.3. It is a tautomer of an epsilon-(gamma-glutamyl)lysine.
(2S)-2-azaniumyl-6-[[(4S)-4-azaniumyl-4-carboxylatobutanoyl]amino]hexanoate