What does one carbon metabolism of folic acid mean?

[scilearner]

What does that mean. Transfer of 1-carbon unit. What is a 1-carbon unit, are they referring to carbon number 1(according to nomenclature) of the molecule being transferred or a single carbon atom from the molecule is transferred? Can anyone explain. Thanks

Edited February 21, 2011 by scilearner

[Horza2002]

Ok, I'll try keep this simple. Basically what it means, is that you are moving a carbon atom around between molecules. One specific example is the role of folate (also known as folic acid) is in the methylation of homocysteine using Vitamin B12; look at the file I've attached.

 

Vitamin B12 is a cofactor required for the correct function of the enzyme methionine synthase. The His ligand on the bottom axial position of the cobalt and anchors it to the enzyme.

 

Basically, the folate brings a new methyl group to the Vitamin B12 system so that it can continue on its catalytic cycle transfering it to homocysteine to generate methionine. The Co(I) species has a lone pair of electrons which then acts as a nucleophile to remove the methyl group from Me-folate. This leaves folate without the methyl group (the red section in the file). Once this has happened, the Co(III) activates the methyl group to attack by the sulphur of homocycteine. In terms of your title, it means transferring a methyl group from the folate to another molecule.

 

Folate is also resoponsible for regenerating S-Adenosyl methionine once it has transfered the methyl group to another molecule in essentially the same manor as I have shown in the file. So in anwser to your question, it means moving a carbon atom from one molecule to another.

Folate.pdf

[John Cuthber]

Incidentally, the reason it's important is that biology often moves two carbon atoms around at the same time using things like acetyl coenzyme a

http://en.wikipedia.org/wiki/Acetyl-CoA

Folate is odd in that it moves a single carbon.