Folates biological function

A number of both pre-clinical and clinical studies have used the folate receptor or EBP as a target for immunotherapy of ovarian carcinoma [31,32]. Expression of this tumour-associated antigen by normal tissues is restricted [33]. The carcinoma-associated antigen, EGP-2, also called EpCAM, is a 38-kDA transmembrane glycoprotein, present on the majority of simple, stratified and transitional epithelia [34]. The biological function of EGP-2 has not yet been established. 

For further elucidation of biological function of GPI anchor, the behaviour of those GPI anchor analogues together with the native GPI anchor was accessed in living cells. Transiently expressed native GPI-anchored protein, decay-accelerating factor (DAF) or the folate receptor (FR), GFP-2, GFP-3 or GFP-4 was tested on HeLa cell surface. FCS analysis revealed a correlation between the structure of the glycan core and lateral mobility in the cell membrane (Fig. 6c, d). GFP-2 displayed... 

Polysaccharide capsules coated with lipid molecules have been shown not only to provide a sealed barrier to prevent the leakage of the encapsulated drug, but also can be used as a means to attach biological functionality to the capsule surface [98]. Thus, neoglycolipid incorporated into the supported lipid membrane displayed high efficiency in lectin binding smdies (concanavalin A), while a folate-linked lipid in the lipid membrane provided a functional capacity to target cancer cells (MCF-7). 

Rothem, L., Stark, M., Kaufman, Y., Mayo, L., and Assaraf, Y.G. (2004) Reduced folate carrier gene silencing in multiple antifolate-resistant tumor cell lines is due to a simultaneous loss of function of multiple transcription factors but not promoter methylation. Journal of Biological Chemistry. 279, 374-384. 

Whetstine, J.R., Witt, T.L., and Matherly, L.H. (2002) The human reduced folate carrier gene is regulated by the AP2 and spl transcription factor families and a functional 61-base pair polymorphism. Journal of Biological Chemistry. 277, 43873-43880. 

Some itamirLS are water soluble, while others are fat soluble. This classification is valuable as it indicates whether the vitamin is likely to be absorbed similarly to lipids or like other water-soluble nutrients. The fat-soluble vitamins are A, D, E, and K. The water-soluble vitamins arc ascorbic acid, biotin, folate, niacin, pantothenic acid, riboflavin, thiamin, vitamin B i, and vitamin B 2. The classification is also valuable, as it helps chemists decide on the best way to extract and analyze a particular vitamin in foods and biological tissues. Aside from having some bearing on the path ways of absorption and distribution throughout the body, the question of whether a particular vitamin is fat soluble or water soluble has little or no relevance to its function in the body. 

Either a primary deficiency of folic acid or functional deficiency secondary to vitamin Bj2 deficiency will have the same effect. In folate deficiency, addition of any biologically active form of folate, but not vitamin B, will normalize the dUMP suppression of [ H]thymidine incorporation. In vitamin B deficiency, addition of vitamin B or methylene-tetrahydrofolate, but not methyl-tetrahydrofolate, will normalize dUMP suppression. 

Riboflavin, also called vitamin B2, is stmcturally composed of an isoafloxazine ring with a ribityl side chain at the nitrogen at position 10. This vitamin functions metabol-icafly as the essoitial component of two flavin coenzymes, flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), complexed with proteins, which act as intmnediaries in transfers of electrons in biological oxidation-reduction reactions. Both FAD and FMN function as coenzymes for flavoproteins of flavoenzymes. Flavoproteins are essoitial for the metabolism of carbohydrates, amino acids, and lipids and for pyridoxine and folate conversion to their respective coenzyme forms. 

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