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In enzymology, a proline racemase () is an enzyme that catalyzes the chemical reaction :L-proline D-proline Hence, this enzyme has two substrates, L- and D-proline, and two products, D- and L- proline. This enzyme belongs to the family of proline racemases acting on free amino acids. The systematic name of this enzyme class is proline racemase. This enzyme participates in arginine and proline metabolism. These enzymes catalyse the interconversion of L- and D-proline in bacteria. == Species distribution == This first eukaryotic proline racemase was identified in ''Trypanosoma cruzi'' and fully characterized . The parasite enzyme, ''Tc''PRAC, is as a co-factor-independent proline racemase and displays B-cell mitogenic properties when released by ''T. cruzi'' upon infection, contributing to parasite escape. Novel proline racemases of medical and veterinary importance were described respectively in ''Clostridium difficile'' () and ''Trypanosoma vivax'' (). These studies showed that a peptide motif used as a minimal pattern signature to identify putative proline racemases (motif III *) is insufficient stringent ''per se'' to discriminate proline racemases from 4-hydroxyproline epimerases (HyPRE). 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. Based on those elements, enzymes incorrectly described as proline racemases were biochemically proved to be hydroxyproline epimerases (i.e. HyPREs from ''Pseudomonas aeruginosa'' (Q9I476), ''Burkholderia pseudomallei'' (), ''Brucella abortus'' (), ''Brucella suis'' () and ''Brucella melitensis'' ().〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Proline racemase」の詳細全文を読む スポンサード リンク
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