Tetrahydrofolates Are Greatly Stabilized by Binding to Bovine Milk Folate-Binding Protein

• Published in: The Journal of nutrition Vol. 132; no. 9; pp. 2690 - 2694
• Main Authors: Jones, Martina L., Nixon, Peter F.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.09.2002; American Society for Nutritional Sciences; American Institute of Nutrition
• Subjects: 5-methyltetrahydrofolate; Animals; bioavailability; Biological and medical sciences; Biological Availability; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Cattle; Drug Stability; Folate Receptors, GPI-Anchored; folate-binding protein; folic acid; Fundamental and applied biological sciences. Psychology; Half-Life; Hydrogen-Ion Concentration; Milk; Milk - chemistry; Milk - metabolism; Mother. Fetoplacental unit. Mammary gland. Milk; neonates; Nutrition; Pregnancy. Parturition. Lactation; Proteins; Receptors, Cell Surface; Solubility; Temperature; tetrahydrofolate; Tetrahydrofolates - metabolism; Vertebrates: reproduction; Vitamins; folate-binding protein; 5-methyltetrahydrofolate; DTE; 5-CH3H4folate; FBP; pABG; 5-CH3H2folate; TBAP; WPC; H4folate; tetrahydrofolate; Micronutrient; Human; Binding protein; Chemical stabilization; Cow milk; Bioavailability; Folic acid; Folate
• ISSN: 0022-3166; 1541-6100
• DOI: 10.1093/jn/132.9.2690

The dietary supply of folates and their measurement are both affected, potentially, by the instability of some folates. Labile folates appear to be stabilized by binding to folate-binding protein (FBP); this paper reports measurements of that stabilization. The degradation rates of the very labile tetrahydrofolate (H4folate) and moderately labile 5-methyltetrahydrofolate (5-CH3H4folate) were measured with the compounds free or bound to either soluble or immobilized bovine milk FBP. Complexation increased stability from 2- to > 1000-fold, depending on buffer and temperature conditions. H4folate at 4°C and pH 6.7 appeared to be quite stable for > 100 d when bound to soluble FBP but had a half-life of < 1 h when free. Stabilization of milk folates may be a role of FBP and would improve the bioavailability of milk folate to newborns and other consumers.