Asparagine
MW: 132.12 g/ mol-1
Asparagine has a chemical formula of C4H8N2O3. It can be abbreviated as Asn, or N. The structural name is 2-Amino-3-carbamoylpropanoic acid. In 1806, two chemists isolated this amino acid in a crystallized structure. This was the first of the amino acids to be isolated. Asparagine is a nonessential amino acid (body can make its own supply) that can be found in many proteins as well as plants. This is an important amino acid because it is necessary for the synthesis of many proteins.
The functional groups include an amine, amide, and a carboxylic acid that is a carboxamide (side chain functional group).
This amino acid provides key sites for N-linked glycosylation modification of the protein chain with the addition of carbohydrate chains. Asparagine also plays an important role in the metabolism of ammonia, which is toxic in the human body. The nervous system needs asparagine to maintain balance, as well as in amino acid transformation.
PKa Values
Equation: pKa = -log Ka
Ka = [H+] x [X-] / [HX]
The Pka values of Asparagine
3Pka of carboxylic acid = 2.02
3Pka of amino acid = 8.08
Isoelectric Point
pI = (pKa1 + pKa2)/2
(2.02 + 8.08) / 2 = 5.41 pH
The isoelectric point for asparagine is 5.41 pH. This means that the amino acid has an equal number of positive and negative charges at this pH level.
IR Spectrum
Synthesis
4Aparagine is the product of amidation of aspartate. Aspartate is developed into asparagine in an ATP-dependent reaction catalyzed by asparagine synthetase, and glutamine is the amino group donor. The process is shown in the picture below.
Citations:
1.) http://www.chemie.fu-berlin.de/chemistry/bio/aminoacid/asparagin_en.html
2.) http://www.newworldencyclopedia.org/entry/Asparagine
Nicely done J. I like how you gave a little bit of background information on how and when the amino acid was first isolated and identified. Good illustration of the molecule and how the pKa values and the isoelectric point can be determined.
ReplyDeleteHowever, a subject that you could have addressed and explained a little more in depth to your readers was the IR spectrum data. You could have elaborated on why and where peaks pertaining to a functional group was found.
Interesting synthesis of the amino acid. I wonder if it could be done in a lab setting...
Good job J!
Good luck on the test monday =)
A.E.