Proteolysis of endomorphin-1 by brain synaptic membrane-associated peptidases
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Updated: Oct 1, 2026

Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization
Published on: May 12, 2017
Liming Wu1, Junhui Chen, Dulai Zhong
1Pharmaceutic Biotechnology Key Laboratory, Nanjing University, Nanjing 210093, P. R. China.
Abstract:
The biotransformation of endomorphin-1 (EM-1) by brain synaptic membranes has been studied. Peptide fragments of EM-1 that were formed during incubation with membrane preparations in vitro were isolated by High-performance liquid chromatography (HPLC) and characterized using determination of amino acid composition. At pH 7.4, two degradation products, EM-1(1-3) and EM-1(1-2), were identified. EM-1 was degraded 77.5% at 30 min incubation with synaptic membranes. The time course of the experiments and the effect of carboxypeptidase inhibitor (CPI) demonstrated that the proteolysis reaction involves the participation of carboxypeptidase activity.
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