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L-alanine is second only to L-leucine in rate of occurrence, accounting for 7.8% of the primary structure in a sample of 1,150 proteins. [5] The right-handed form, D -alanine, occurs in peptides in some bacterial cell walls [ 6 ] : 131 (in peptidoglycan ) and in some peptide antibiotics , and occurs in the tissues of many crustaceans and ...
Alanine is produced by the transamination of one molecule of pyruvate using two alternate steps: 1) conversion of glutamate to α-ketoglutarate using a glutamate-alanine transaminase, and 2) conversion of valine to α-ketoisovalerate via Transaminase C. Not much is known about the regulation of alanine synthesis.
β-Alanine (beta-alanine) is a naturally occurring beta amino acid, which is an amino acid in which the amino group is attached to the β-carbon (i.e. the carbon two carbon atoms away from the carboxylate group) instead of the more usual α-carbon for alanine (α-alanine). The IUPAC name for β-alanine is 3-aminopropanoic acid.
A feature of the native chemical ligation technique is that the product polypeptide chain contains cysteine at the site of ligation. The cysteine at the ligation site can be desulfurized to alanine, thus extending the range of possible ligation sites to include alanine residues. Other beta-thiol containing amino acids can be used for native ...
A further variant is suitable for continuous production, in which ammonia, methanal and hydrogen cyanide react at pH 6 to form iminodiacetonitrile, which in a strongly acidic medium (pH 1.5) reacts with ethanal to produce trinitrile methylglycinonitrile-N,N-diacetonitrile in a very good yield of 92%. (step 1).
In the experiments by Macko et al., alanine indeed had a δ 13 C value slightly higher than that of cyanobacterial photosynthate. [5] Valine is synthesized by the addition of a 13 C depleted acetyl group to pyruvate. Consistent with this mechanism, Takano et al. [7] found valine to be depleted in 13 C relative to alanine in anaerobic ...
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The pH-dependence of the activity displayed by enzymes and the pH-dependence of protein stability, for example, are properties that are determined by the pK a values of amino acid side chains. The p K a values of an amino acid side chain in solution is typically inferred from the p K a values of model compounds (compounds that are similar to ...