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Publication Abstract from PubMed

BACKGROUND: Herein we report the discovery of a cystine-crosslinked peptide from Porifera along with high-quality spatial details accompanied by the description of its unique effect on neuronal calcium influx. METHODS: Asteropsin A (ASPA) was isolated from the marine sponge Asteropus sp., and its structure was independently determined using X-ray crystallography (0.87A) and solution NMR spectroscopy. RESULTS: An N-terminal pyroglutamate modification, uncommon cis proline conformations, and absence of basic residues helped distinguish ASPA from other cystine-crosslinked knot peptides. ASPA enhanced Ca(2+) influx in murine cerebrocortical neuron cells following the addition of the Na(+) channel activator veratridine but did not modify the oscillation frequency or amplitude of neuronal Ca(2+) currents alone. Allosterism at neurotoxin site 2 was not observed, suggesting an alternative to the known Na(+) channel interaction. CONCLUSIONS: Together with a distinct biological activity, the origin of ASPA suggests a new subclass of cystine-rich knot peptides associated with Porifera. GENERAL SIGNIFICANCE: The discovery of ASPA represents a distinctive addition to an emerging subclass of cystine-crosslinked knot peptides from Porifera.

Asteropsin A: An unusual cystine-crosslinked peptide from porifera enhances neuronal Ca(2+) influx.,Li H, Bowling JJ, Fronczek FR, Hong J, Jabba SV, Murray TF, Ha NC, Hamann MT, Jung JH Biochim Biophys Acta. 2012 Nov 29;1830(3):2591-2599. doi:, 10.1016/j.bbagen.2012.11.015. PMID:23201194^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.