Search results
Results from the WOW.Com Content Network
Serine (symbol Ser or S) [3] [4] is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − NH +3 form under biological conditions), a carboxyl group (which is in the deprotonated − COO −
Tetrahydrobiopterin (BH 4, THB), also known as sapropterin (), [5] [6] is a cofactor of the three aromatic amino acid hydroxylase enzymes, [7] used in the degradation of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT), melatonin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and is a cofactor for the ...
Structure of a typical L-alpha-amino acid in the "neutral" form. Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. [1] Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. [2]
Threonine (symbol Thr or T) [2] is an amino acid that is used in the biosynthesis of proteins.It contains an α-amino group (which is in the protonated −NH + 3 form when dissolved in water), a carboxyl group (which is in the deprotonated −COO − form when dissolved in water), and a side chain containing a hydroxyl group, making it a polar, uncharged amino acid.
Phosphomimetics are amino acid substitutions that mimic a phosphorylated protein, thereby activating (or deactivating) the protein. Within cells, proteins are commonly modified at serine, tyrosine and threonine amino acids by adding a phosphate group. Phosphorylation is a common mode of activating or deactivating a protein as a form of ...
l-DOPA is produced from the amino acid l-tyrosine by the enzyme tyrosine hydroxylase. l-DOPA can act as an l-tyrosine mimetic and be incorporated into proteins by mammalian cells in place of l-tyrosine, generating protease-resistant and aggregate-prone proteins in vitro and may contribute to neurotoxicity with chronic l-DOPA administration. [10]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Like other natural proteinogenic amino acids, cysteine and selenocysteine have L chirality in the older D / L notation based on homology to D - and L-glyceraldehyde. In the newer R / S system of designating chirality, based on the atomic numbers of atoms near the asymmetric carbon, they have R chirality, because of the presence of sulfur or ...