Poly D Glutamic Acid Capsule -

-PGA) is a naturally occurring, water-soluble, biodegradable, and non-toxic polymer composed of repeated units of the amino acid D-glutamic acid. Unlike the L-amino acids standard in human protein production, the D-isoform used by B. anthracis is resistant to the proteolytic enzymes of the host immune system.

Bacillus anthracis Poly-γ-D-Glutamate Capsule Inhibits Opsonic ... - PMC poly d glutamic acid capsule

| Feature | PDA (B. anthracis) | Hyaluronic acid (S. pyogenes) | Polysaccharide (S. pneumoniae) | |--------|--------------------|-------------------------------|-------------------------------| | Monomer | D-glutamic acid | Glucuronic acid + N-acetylglucosamine | Glucose, rhamnose, etc. | | Polymer type | Polypeptide | Polysaccharide | Polysaccharide | | Isomer specificity | D-amino acid | D-glucuronic acid | Variable | | Antigenicity | Weak (non-immunogenic in many hosts) | Non-immunogenic (molecular mimicry) | Immunogenic (serotype-specific) | | Vaccine target | Yes (conjugate vaccines in development) | No | Yes (Prevnar, Pneumovax) | pyogenes) | Polysaccharide (S