Polyglutamic acid

Polyglutamic acid (PGA) is a polymer of the amino acidglutamic acid (GA). Depending on where the individual monomers connect, PGA can be gamma PGA (poly-γ-glutamic acid, γ-PGA), the form where the peptide bonds are between the amino group of GA and the carboxyl group at the end of the GA side chain, or alpha PGA, the form where the alpha-carboxyl is used to form the peptide bond.

Gamma PGA is formed by bacterialfermentation. It is a major constituent of the Japanese food nattō and has a wide range of uses.

Alpha PGA has been investigated as a drug delivery system.