Proline racemase

Also, additional, non-dissociated elements that account for the discrimination of these enzymes were identified, based for instance on polarity constraints imposed by specific residues of the catalytic pockets.

[4] The biochemical mechanism of proline racemase was first put forward in the late sixties by Cardinale and Abeles[6] using the Clostridium sticklandii enzyme, CsPRAC.

The catalytic mechanism of proline racemase was late revisited by Buschiazzo, Goytia and collaborators that, in 2006, resolved the structure of the parasite TcPRAC co-crystallyzed with its known competitive inhibitor - pyrrole carboxylic acid (PYC).

P2C acts as a competitive inhibitor, due to the chemical’s similarity to the transition state of the natural proline substrate.

Pyrrole-2-carboxylic acid (P2C) reveals the presence of one catalytic center per monomer, with two Cys residues present to perform acid/base catalysis, utilizing a carbanion stabilization mechanism.