The folate trap involves the 'folate cycle'.
Here is the 'folate cycle' (which is typically drawn in a circle):
Tetrahydrofolate (TH4) -> 5,10 Methylene-TH4 -> Methyltetrahydrofolate -> Tetrahydrofolate (TH4)
This is a 'cycle' because TH4 (the starting point) is regenerated.
The problem that can lead to the 'folate trap' is that the last step of the cycle, the conversion of methytetrahydrolfolate to TH4 (the enzyme is methylene - tetrahydro - folate - reductase - MTHFR), requires Vitamin B12. In the absence of B12 (Vitamin B12 deficiency is quite common, especially in the elderly), the folate cycle gets 'trapped' at methyltetrahydrofolate and can't continue to regenerate TH4.
High doses of supplemental folate can 'mask' the effects of B12 deficiency by compensating for the trapped folate (as methyltetrahydrofolate). So, high doses of folate can mask the anemia that would result from a severe B12 deficiency. Chronic B12 deficiency has serious consequences (even without the anemia) such as damage to the nervous system and the creation of a peripheral neuropathy.
Hope this was helpful. Best wishes.
2007-11-05 03:57:53
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answer #1
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answered by Doctor J 7
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Define Folate
2016-11-03 06:30:04
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answer #2
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answered by Anonymous
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basically to put it simply folate comes in from the diet and is needed to make a molecule for example purine in dna..however the pathway to use folate goes through a pathway from folate in the diet which then joined to a hydorxymethyl group (CH2OH) of serine to make N5,N10 hydroxymethylene FH4. This substrate however instead of carrying on and making N5,N10 methenyl-FH4 and consequently N10-formyl FH4 to incorporate into purine it is instead a substrate for an irreversible reaction to make N5-methyl FH4. The reason this N5-methyl FH4 is made is to convert a potentially toxic substrate homocysteine in the cell back to methionine and uses an enzyme (methionine synthase) which requires vitiman B12 as a cofactor. . (This homocysteine is a product of S-adenosylmethionine which is an essential methylation reagent for several critical reactions including the methylation of nucleic acids, protein residues and epinephrine). So the folate trap therefore is that the reaction that creates the substrate is irreversible and the conversion of homocystiene to methionine requires a cofactor (Vitiman B12) that may not be availableto convert this so the folate remains trapped as N5-methyl FH4.
If the cofactor Vit B12 is present then all is good, methionine can be made and FH4 is released and can be incorporated into serine to become the N5,N10-methylene FH4.
I hope this answers your question..:D good luck!
2007-11-05 19:50:20
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answer #3
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answered by k j 1
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Methylfolate Trap
2016-12-17 03:23:05
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answer #4
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answered by Anonymous
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This Site Might Help You.
RE:
what is a folate trap?
plz add details if u know ne.......plz answer dis as soon as possible
2015-08-16 16:15:48
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answer #5
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answered by Anonymous
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A synergistic relationship exists between folate and vitamin
B12, also called cobalamin. This relationship, whereby
without vitamin B12 the methyl group from 5-methyl THF
can’t be removed and thus is trapped, is sometimes called
the “methyl-folate trap.” The following sequence of events
leads to the methyl-folate trap. Serine donates
single carbons through conversion to glycine, and in the
process THF is converted to 5,10-methylene THF. The 5,
10-methylene THF is readily reduced to 5-methyl THF by
a reductase (whose activity is inhibited by its end product,
5-methyl THF, and by SAM). 5-methyl THF is required for
methionine synthesis from homocysteine. Methyl groups
are transferred by the enzyme methionine synthase from
5-methyl THF to vitamin B12. Adequate vitamin B12 must
be present for the activity of methionine synthase. The
addition of the methyl group to cobalamin generates
methylcobalamin, which serves as the methyl donor for
converting homocysteine to methionine. Without cobalamin
to accept the methyl group from 5-methyl THF, the
5-methyl THF accumulates and is trapped, and THF is not
regenerated. With adequate vitamin B12 status, the THF
resulting from the synthesis of methionine is needed as asubstrate for conversion into its various other coenzyme
forms. For example, 10-formyl THF is needed for purine
synthesis, and 5,10-methylene THF is needed for thymidylate
synthesis, which in turn must be present for DNA
synthesis. Thus, the synergism between folate and vitamin
B12 is very important for support of rapidly proliferating
cells.
2015-09-14 02:03:32
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answer #6
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answered by Harshvardhan 1
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1
2017-01-24 22:31:01
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answer #7
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answered by ? 4
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