Dynorphin A 1-17 biotransformation in inflamed tissue, serum and trypsin solution analysed by liquid chromatography Ctandem mass spectrometry

• Published in: Analytical and bioanalytical chemistry Vol. 404; no. 10; pp. 3111 - 3121
• Main Authors: Morgan, M, Herath, H M D R, Cabot, P J, Shaw, P N, Hewavitharana, A K
• Format: Journal Article
• Language: English
• Published: 01.12.2012
• Subjects: Analgesia; Biotransformation; Fragments; Mass spectrometry; Mathematical analysis; Serums; Trypsin
• ISSN: 1618-2642
• DOI: 10.1007/s00216-012-6406-8

Dynorphin A 1-17 (DYN A) is an endogenous neuropeptide that is of interest due to its diverse roles in analgesia, inflammation and addiction. Upon release, DYN A is subject to metabolism by a range of enzymes and its biotransformation is dependent on the site and environment into which it is released. In this study, we investigated the biotransformation of DYN A in rat inflamed tissue at pH 7.4 and 5.5, in rat serum and in trypsin solution. DYN A-porcine was incubated at 37 degree C in each matrix over a range of incubation periods. The resultant fragments were separated using a C4 column and detected by mass spectrometry using total ion current mode. Incubation of DYN A in trypsin solution and in rat serum resulted in 6 and 14 fragments, respectively. Incubation in inflamed rat paw tissue occasioned 21 fragments at pH7.4 and 31 fragments at pH 5.5. Secondary breakdown of some larger primary fragments was also observed in this study.