D-Amino Acids and Derivatives

Although D-amino acids can be found in nature, only the L-isomers are used to form proteins. The D-isomers are most often found attached to the cell walls of bacteria and in antibiotics that attack bacteria. The presence of D-isomers protects the bacteria from enzymes. These enzymes are generated by the host organism to protect itself from bacterial infection by hydrolyzing the proteins in the bacterial cell wall.