Proline is a nonessential amino acid, which means that it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet.
Proline is the precursor to hydroxyproline, which is a major amino acid found in the connective tissue of the body – collagen.
– Its effect in human nutrition, other than as a source of nitrogen, is not well established.
– Supplementation with proline has not been found to increase collagen formation.
– Proline is found in virtually every dietary protein except lactalbumin. Although proline is not classified as an essential amino acid, proline levels in plasma are dramatically reduced with a proline-free diet.
– Proline is a major constituent of collagen and can be metabolized to alpha-KG, which is important in ammonia detoxification and the citric acid cycle.-
– Hyperprolinemia is a recognized genetic disorder characterized by renal and central nervous system dysfunction.
– Vitamin C and iron are known cofactors in the conversion to hydroxyproline and may be useful if connective tissue symptoms are present. Acute or chronic deficiency of vitamin C produces a significant increase in the proline/hydroxyproline ration in urine.
– The relationship between proline and hydroxyproline urinary excretion has been used as an index of collagen catabolism.
References:
https://ghr.nlm.nih.gov/condition/hyperprolinemia
Proline (Plasma)
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