Dynorphin A(1-17) biotransformation in striatum of freely moving rats using microdialysis and matrix-assisted laser desorption/ionization mass spectrometry |
| |
Authors: | Reed Brian Zhang Yong Chait Brian T Kreek Mary Jeanne |
| |
Institution: | Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, New York, USA. reedb@rockefeller.edu |
| |
Abstract: | The biotransformation of the opioid peptide dynorphin A(1-17) was investigated in striatum of freely moving Fischer rats, by direct infusion of this peptide, followed by recovery of the resulting biotransformation products via microdialysis and identification using matrix-assisted laser desorption/ionization mass spectrometry. The observed peptides are consistent with enzymatic cleavage at the Arg7-Ile8 position of dynorphin A(1-17), followed by terminal degradation of the resulting dynorphin A(1-7) and dynorphin A(8-17) peptides. Unexpectedly, novel post-translational modifications were found on C-terminal fragments of dynorphin A(1-17). Using tandem mass spectrometry, a covalent modification of mass 172 Da, the nature of which is not understood, was found on the tryptophan residue of C-terminal fragments (Trp14). Additional modifications, of mass 42 and 113 Da, were also found on the N-terminus (Ile8 or Pro10) of these same C-terminal fragments. The role of these modifications of C-terminal fragments has not yet been characterized. |
| |
Keywords: | Fischer rat opioid peptide post-translational modification tryptophan modification |
本文献已被 PubMed 等数据库收录! |
|