Small peptides patterned after the N-terminus domain of SNAP25 inhibit SNARE complex assembly and regulated exocytosis
Article first published online: 1 DEC 2003
Journal of Neurochemistry
Volume 88, Issue 1, pages 124–135, January 2004
How to Cite
Blanes-Mira, C., Merino, J. M., Valera, E., Fernández-Ballester, G., Gutiérrez, L. M., Viniegra, S., Pérez-Payá, E. and Ferrer-Montiel, A. (2004), Small peptides patterned after the N-terminus domain of SNAP25 inhibit SNARE complex assembly and regulated exocytosis. Journal of Neurochemistry, 88: 124–135. doi: 10.1046/j.1471-4159.2003.02133.x
- Issue published online: 1 DEC 2003
- Article first published online: 1 DEC 2003
- Received July 2, 2003; revised manuscript received September 3, 2003; accepted September 14, 2003.
- combinatorial chemistry;
- drug discovery;
- protein–protein interactions;
- synaptic transmission;
- vesicle fusion
Synthetic peptides patterned after the C-terminus of synaptosomal associated protein of 25 kDa (SNAP25) efficiently abrogate regulated exocytosis. In contrast, the use of SNAP25 N-terminal-derived peptides to modulate SNAP receptors (SNARE) complex assembly and neurosecretion has not been explored. Here, we show that the N-terminus of SNAP25, specially the segment that encompasses 22Ala-44Ile, is essential for the formation of the SNARE complex. Peptides patterned after this protein domain are potent inhibitors of SNARE complex formation. The inhibitory activity correlated with their propensity to adopt an α-helical secondary structure. These peptides abrogated SNARE complex formation only when added previous to the onset of aggregate assembly. Analysis of the mechanism of action revealed that these peptides disrupted the binary complex formed by SNAP25 and syntaxin. The identified peptides inhibited Ca2+-dependent exocytosis from detergent-permeabilized excitable cells. Noteworthy, these amino acid sequences markedly protected intact hippocampal neurones against hypoglycaemia-induced, glutamate-mediated excitotoxicity with a potency that rivaled that displayed by botulinum neurotoxins. Our findings indicate that peptides patterned after the N-terminus of SNAP25 are potent inhibitors of SNARE complex formation and neuronal exocytosis. Because of their activity in intact neurones, these cell permeable peptides may be hits for antispasmodic and analgesic drug development.