Dargininecontaining

Dargininecontaining refers to chemical entities that include one or more residues of the amino acid D-arginine, the noncanonical enantiomer of the proteinogenic L-arginine. In practice, the term is used to describe peptides, peptidomimetics, or small molecules that incorporate D-arginine as a structural component.

D-arginine is rarely found in ribosomally synthesized proteins, where L-arginine predominates, but it occurs in certain nonribosomal peptides and cyclic peptides, and can be introduced synthetically. In peptides, the presence of D-arginine can influence conformational preferences, increase resistance to proteolysis, and alter interactions with receptors or enzymes compared with the L-enantiomer.

Synthesis and incorporation: D-arginine can be incorporated via solid-phase peptide synthesis using commercially available D-arginine building blocks. In biosynthetic contexts, racemization or specific epimerization processes are required, though such mechanisms are uncommon in human biology.

Applications: D-arginine-containing compounds are studied for improved metabolic stability, altered pharmacokinetics, and potential therapeutic activity. They appear in drug design, antimicrobial peptides, enzyme inhibitors, and as components of peptidomimetics.

Analytical considerations: Detecting and quantifying D-arginine residues typically involves chiral chromatography or derivatization methods after acid hydrolysis, since standard amino acid analysis may not distinguish enantiomers without chiral resolution.

See also: D-amino acid, arginine, enantioselectivity, nonribosomal peptide, peptidomimetic.