Linear Peptide (IMAGE) University of Toronto Caption This peptide consists of three amino acids: Aspartic acid (Asp), Valine (Val) and Serine (Ser). The natural L-form is on the left and the synthetic D-form is on the right Credit Pablo Gainza Usage Restrictions credit the source License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.