CAS Number: 115388-96-0 Molecular Weight: 510.26 Salt Form: TFA Purity: >96% Sequence (3-letter): D-Phe-Pro-Lys-pNA Sequence (1-letter): fPK-pNA Storage: -20 ?C or below D-Phe-Pro-Lys-pNA is a substrate for Thrombin. Activity is quantified by the release of p-nitroaniline which is measured by absorbance at 405 nm.