Possible Interaction: Glutamine and Proline

“Although the interconvertibility of proline and glutamine has been long established, recent findings showed that the proto-oncogene, cellular myelocytomatosis oncogene, upregulates glutamine utilization (glutaminase) and routes glutamate to proline biosynthesis (pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductases).”

“But proline and glutamine are interconvertible and linked in their metabolism.”

“Biosynthetic networks linked with non‐essential amino acids alanine, serine, arginine, and proline are also significantly impacted by the use of glutamine as an alternate carbon source.”

“The cellular metabolism of glutamine and proline are closely interrelated, because they can be interconverted with glutamate and ornithine via the mitochondrial pathway involving pyrroline-5-carboxylate (P5C).”

“Here we provide evidence that the spacing between glutamine and proline , the second most abundant amino acid in gluten, plays an essential role in the specificity of deamidation.”

“In muscles from untreated animals, decreased leucine oxidation after the addition of GLN to the medium was associated with decreased protein synthesis in the SOL and decreased concentrations of serine, glycine, histidine, alanine, arginine, proline , and lysine in both muscles.”

“In batch culture, the overflow metabolism of glutamine ends in excess production of ammonium and the amino acids alanine, proline , ornithine, asparagine, glutamate, serine and glycine.”

“Plasma levels of proline , alanine and citrulline were significantly higher in the Gln P and Gln F groups than in the Gln 0 group.”

“The synthesis of ornithine, citrulline, and arginine from 0.5-5 mM proline was concentration dependent and required the addition of glutamine.”

“The glutamine solution decreased the levels of proline , ornithine and tyrosine in the plasma of rats eating the cafeteria diet.”

“ Proline also inhibited glutamine transport less in vesicles from acidotic rats.”

“ Proline inhibited glutamine uptake by kidney slices and this inhibition was markedly less in slices from acidotic rats or in slices incubated in a sodium free buffer.”