Comparative Aspects of Tissue Glutamine and Proline Metabolism

The Effect of L-Proline on Two Recombinant AMPA Glutamate Receptors

“…Each of these conditions is caused by a mutation or deletion in one of the genes coding for proteins in the metabolic pathways of proline (Figure 1-1) (Bertolo and Burrin 2008;Mitsubishi et al 2008). Only three of these conditions, HPI, HPII and P5C synthase deficiency, however result in changes in plasma and CSF concentration of proline (Phang et al 2001).…”

“…Hyperprolinemia type II is caused by a mutation of deletion in the Δ-1-proline-5-carboxylate acid dehydrogenase (P5CDH). Reprinted with permission from Bertolo RF, Burrin DG (2008 autism, epilepsy as well as neuronal disorders which include mental retardation, epilepsy and delays in psychomotor development, as well as aggression in some patients (Flynn et al 1989, Afenjar et al 2007, Zinkstok et al 2008. Thus, it is important to understand the actions of proline, particularly within the CNS.…”

“…It can be derived from glutamine in the liver, small intestine and the kidney (Bertolo and Burrin 2008). L-proline is one of the major amino acid constituent of extracellular fluid with a plasma concentration of 37-312 µM (Phang et al 2001;Afenjar et al 2007).…”

“…The conversion of glutamate and glutamine into the intermediate P5C is catalyzed by the enzyme P5C synthase (Figure 1-1) (Bertolo and Burrin 2008). This step which is central to the synthesis/metabolism of proline is restricted to the gut (Jones 1985;Bertolo and Burrin 2008).…”

“…The conversion of glutamate and glutamine into the intermediate P5C is catalyzed by the enzyme P5C synthase (Figure 1-1) (Bertolo and Burrin 2008). This step which is central to the synthesis/metabolism of proline is restricted to the gut (Jones 1985;Bertolo and Burrin 2008). Mutation of enzymes in the metabolic pathways controlling the synthesis (anabolism) as well as the breakdown (catabolism) of proline, results in disease conditions which include hyperprolinemia (Phang et al 2001).…”