Glycine.
Glycine consists of a single carbon molecule attached to an amino and a carboxyl group. Its small size helps it to function as a flexible link in proteins and allows for the formation of helices, an extracellular signaling molecule, recognition sites on cell membranes and enzymes, a modifier of molecular activity via conjugation and glycine extension of hormone precursors, and an osmoprotectant. There is substantial experimental evidence that free glycine may have a role in protecting tissues against insults such as ischemia, hypoxia, and reperfusion. This impressive catalogue of functions makes an interesting contrast with glycine's perceived metabolic role as a nonessential amino acid. Glycine interconverts with serine to provide a mechanism for the transfer of activated one-carbon groups. Glycine has just been viewed as a convenient source of nitrogen to add to solutions of nutrients. Although this may have unexpected benefits when such solutions are used in clinical practice, it does raise the specter of a possible confounding effect in experiments when glycine is added to control solutions to make them isonitrogenous.
Hall
J C
JC
University Department of Surgery, Royal Perth Hospital, Western Australia, Australia.
D000818:Animals; D019610:Cytoprotection; D005998:Glycine / Q000378:metabolism / Q000502:physiology* / Q000627:therapeutic use; D006801:Humans; D008099:Liver / Q000378:metabolism
D005998:Glycine