libero - 4-5-2010 at 12:52
Ok i must make Methylation of some chemical substance whit SAM.
How i know that my substance is "methylated" and how many SAM i must added that my substance is complitly "methylated" ??
not_important - 4-5-2010 at 16:37
The meanings of SAM that I am most familiar with are Surface-to-Air Missile, the Singapore Art Museum, and the Society of American Magicians; none of
these would seem to be useful for methylation. Perhaps including the procedure name and/or a link to a reference on it would further the obtaining an
answer to your question.
kclo4 - 4-5-2010 at 17:09
http://en.wikipedia.org/wiki/S-Adenosyl_methionine
That is the SAM he is talking about.
JohnWW - 4-5-2010 at 17:40
Not_Important overlooked Uncle SAM, however (An abbreviation for Samuel). It also means "Saved Amipro File", used as the extension .sam of files
composed in the format of this Lotus word-processor program.
The stuff, which occurs naturally in the body and is also synthesized, contains a positively-charged sulfonium (SRR'R"+) group, in which one of the
attachments is a CH3 group, which is easily detached as a CH3+ which adds to other biochemicals in metabolism. Unfortunately for druggies, it cannot
be used in making "meth".
SAM is sold in the U$A as a nutritional supplement as "SAM-e" (or SAME or SAMe); and in Europe it is sold as Gumbaral, Samyr, Adomet, Heptral as a
prescription drug. Some research has indicated that taking it regularly may help fight depression, liver disease, and the pain of osteoarthritis.
Here are the first few paragraphs from the Wikipedia article referenced above by KClO4:
S-Adenosyl methionine (SAM, SAMe, SAM-e) is a common co-substrate involved in methyl group transfers. SAM-e was first discovered in Italy by G. L.
Cantoni in 1952.[1] It is made from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase (EC 2.5.1.6). Transmethylation,
transsulfuration, and aminopropylation are the metabolic pathways that use SAM. Although these anabolic reactions occur throughout the body, most SAM
is produced and consumed in the liver.[1]
The methyl group (CH3) attached to the methionine sulfur atom in SAM is chemically reactive. This allows donation of this group to an acceptor
substrate in transmethylation reactions. More than 40 metabolic reactions involve the transfer of a methyl group from SAM to various substrates such
as nucleic acids, proteins, and lipids.
In bacteria, SAM is bound by the SAM riboswitch, which regulates genes involved in methionine or cysteine biosynthesis.
The reactions that produce, consume, and regenerate SAM are called the SAM cycle. In the first step of this cycle, the SAM-dependent methylases (EC
2.1.1) that use SAM as a substrate produce S-adenosyl homocysteine as a product.[2] This is hydrolysed to homocysteine and adenosine by
S-adenosylhomocysteine hydrolase EC 3.3.1.1 and the homocysteine recycled back to methionine through transfer of a methyl group from
5-methyltetrahydrofolate, by one of the two classes of methionine synthases (EC 2.1.1.13 or EC 2.1.1.14). This methionine can then be converted back
to SAM, completing the cycle.[3]
[Edited on 5-5-10 by JohnWW]
not_important - 4-5-2010 at 20:48
Lordy Lordy, is that what they meant? Why, I'd never guess that, all that obscureness and lack of references just confused poor old Granny. My sakes,
Uncle Sasha never talked like that, always clear and simple.
And the .SAM extension is very old, being replace by the .LWP after Lotus bought Amipro and upgraded it; IBM kept the file extension after acquiring
Lotus. WordPro 95/97 remains one of the most usable word processors released, but unfortunately lost out to MS Word.