tailieunhanh - Báo cáo khoa học: Identification of bikunin as an endogenous inhibitor of dynorphin convertase in human cerebrospinal fluid

Dynorphin-converting enzymes constitute a group of peptidases capable of converting dynorphins to enkephalins. Through the action of these enzymes, the dynorphin-related peptides bind tod-opioid instead of j-opi-oid receptors, leading to a change in the biological function of the neuro-peptides. | ỊFEBS Journal Identification of bikunin as an endogenous inhibitor of dynorphin convertase in human cerebrospinal fluid Piotr Suder1 Anna Bierczynska-Krzysik1 Agnieszka Kraj1 Peter Brostedt2 Pawel Mak3 Maciej Stawikowski4 Krzysztof Rolka4 Fred Nyberg5 Erik Fries6 and Jerzy Silberring1 7 1 Department of Neurobiochemistry Faculty of Chemistry and RegionalLaboratory Jagiellonian University Krakow Poland 2 Pharmacia Diagnostics AB Uppsala Sweden 3 Faculty of Biotechnology Jagiellonian University Krakow Poland 4 Faculty of Chemistry University of Gdansk Poland 5 Department of PharmaceuticalBiosciences Uppsala University Sweden 6 Department of MedicalBiochemistry and Microbiology Uppsala University Sweden 7 Centre for Polymer Chemistry Polish Academy of Sciences Zabrze Poland Keywords bikunin cerebrospinalfluid dynorphin conversion inhibition opioids Correspondence J. Silberring Department of Neurobiochemistry Faculty of Chemistry Jagiellonian University Ingardena Str. 3 30-060 Krakow Poland Fax 48 12 6340515 Tel 48 12 2927949 E-mail silber@ Received 27 August 2006 accepted 19 September 2006 Dynorphin-converting enzymes constitute a group of peptidases capable of converting dynorphins to enkephalins. Through the action of these enzymes the dynorphin-related peptides bind to ỗ-opioid instead of K-opi-oid receptors leading to a change in the biological function of the neuropeptides. In this article we describe the identification of the protein bikunin as an endogenous competitive inhibitor of a dynorphin-converting enzyme in human cerebrospinal fluid. This protein is present together with its target enzyme in the same body fluids. The KM value of the convertase was found to be 9 pM and the Ki value of the inhibitor was nM. The finding indicates that bikunin may play a significant role as a regulatory mechanism of neuropeptides where one bioactive peptide is converted to a shorter sequence which in turn can affect the action of its longer form. doi .