Monoglutamate

Monoglutamate is a descriptive term used in chemistry and biochemistry to refer to a molecule that contains a single glutamate residue. It contrasts with diglutamates and polyglutamates, which bear two or more glutamate units. The term is most commonly encountered in discussions of folates, where the dietary forms differ from the absorbed forms.

In folate chemistry, natural folates in foods are primarily polyglutamates. The synthetic dietary supplement folic acid is the monoglutamate form, consisting of a pteroylglutamate with a single glutamate residue. In the digestive tract, enzymes such as gamma-glutamyl hydrolase deconjugate polyglutamates to monoglutamate for absorption. After absorption, monoglutamate is converted to various active forms that participate in one-carbon metabolism, essential for DNA synthesis and amino acid interconversion. Within cells, folate coenzymes can be polyglutamated again to enhance retention and catalytic efficiency.

Beyond folates, monoglutamate can describe other molecules bearing a single glutamate moiety, including certain derivatives or drug conjugates. The precise identity of a monoglutamate thus depends on the non-glutamate portion attached to the single glutamate unit.

See also: Glutamate, Folate, Polyglutamate, Gamma-glutamyl hydrolase.