2ndb
From Proteopedia
NMR structure of omega-agatoxin IVA in DPC micelles
Structural highlights
FunctionTX23A_AGEAP Omega-agatoxins inhibit neuronal voltage-gated calcium channels. This toxin acts by modifying the gating of the high voltage activated P-type Cav2.1/CACNA1A channel. Is a potent blocker in both insect and mammalian central neurons.[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedTo analyze structural features of omega-Aga IVA, a gating modifier toxin from spider venom, we here investigated the NMR solution structure of omega-Aga IVA within DPC micelles. Under those conditions, the Cys-rich central region of omega-Aga IVA still retains the inhibitor Cys knot motif with three short antiparallel beta-strands seen in water. However, 15N HSQC spectra of omega-Aga IVA within micelles revealed that there are radical changes to the toxin's C-terminal tail and several loops upon binding to micelles. The C-terminal tail of omega-Aga IVA appears to assume a beta-turn like conformation within micelles, though it is disordered in water. Whole-cell patch clamp studies with several omega-Aga IVA analogs indicate that both the hydrophobic C-terminal tail and an Arg patch in the core region of omega-Aga IVA are critical for Cav2.1 blockade. These results suggest that the membrane environment stabilizes the structure of the toxin, enabling it to act in a manner similar to other gating modifier toxins, though its mode of interaction with the membrane and the channel is unique. Structure-activity relationships of omega-Agatoxin IVA in lipid membranes.,Ryu JH, Jung HJ, Konishi S, Kim HH, Park ZY, Kim JI Biochem Biophys Res Commun. 2017 Jan 1;482(1):170-175. doi:, 10.1016/j.bbrc.2016.11.025. Epub 2016 Nov 9. PMID:27838299[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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