The alpha carbon of naturally occuring alpha amino acids (all but glycine) is a chiral carbon atom. Therefore, each amino acid has two enantiomers, the L- and D-amino acid. L-amino acids represent the 20 natural proteinogenic amino acid, wheras D-amino acids are only rarely found in organisms.
We only use L-amino acids for peptide synthesis (unless you specifically order D-peptides). However, some amino acids, like histidine and cysteine, are prone to racemication (swapping from L to D) during chemical synthesis. The chirality affects the unique 3D structure of each peptide and protein. As the protein or peptide structure is responsible for the recognition by a receptor or an enzyme it is important to ensure enantiomeric integrity of synthetic peptides.
To ensure enantiomery purity we hydrolyze the peptides and analyze the resulting amino acids by gas chromatography using a chiral column to separate amino acid enantiomers.
Material requisition and time needed: upon request