Protein amino acid

Protein amino acids—more accurately called *proteinogenic* or *standard* α-amino acids—are the 20 naturally occurring organic molecules that serve as the building blocks for all proteins in living organisms. Each has a central carbon atom bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a unique side chain ("R" group) that determines its properties. These molecules are linked together by peptide bonds during translation to form polypeptides and functional proteins[1][2][4][10]. Amino acids play diverse roles beyond protein synthesis: - Some act directly as neurotransmitters (e.g., glutamate). - Others serve as precursors for hormones (e.g., tyrosine → thyroid hormones). - They participate in energy metabolism and immune responses. Amino acids are classified based on their side chain properties (nonpolar, polar uncharged, acidic, basic), nutritional requirement (essential vs. non-essential), and other biochemical features[1][4]. There is no single "protein amino acid" molecule; rather this term refers collectively to the set of 20 standard α-amino acids incorporated into proteins by ribosomal translation. Therefore: - This entry is not a specific molecular target but rather describes a class of small molecules essential for life. - It is not considered a therapeutic target like receptors or enzymes; instead it represents fundamental biochemistry. If you require structured information about an individual member of this class—such as "Leucine," "Tyrosine," etc.—please specify the particular amino acid. *Note:* The term “Protein amino acids” is **not itself a valid molecular target**, but refers collectively to all standard protein-building α-amino acids. For drug discovery purposes or therapeutic targeting, one would focus on specific enzymes involved in their metabolism/transportation or on individual signaling functions related to particular residues[1][2].

Other names

Standard amino acidα-amino acidproteinogenic amino acidnatural amino acid