Binding of Ala-scanning analogs of ω-conotoxin MVIIC to N- and P/Q-type calcium channels

• Published in: FEBS letters Vol. 469; no. 2; pp. 147 - 150
• Main Authors: Sato, Kazuki, Raymond, Cecile, Martin-Moutot, Nicole, Sasaki, Toru, Ohtake, Atsuko, Minami, Kazushi, Van Renterghem, Catherine, Kim, Jae Il, Takahashi, Masami, Seagar, Michael J.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 10.03.2000
• Subjects: [125I]GVIA, [125I]ω-conotoxin GVIA; [125I]MVIIC, [125I][Nle12]ω-conotoxin MVIIC; Ala-scanning; Alanine - chemistry; Amino Acid Sequence; Analogs are designated by a letter and number indicating the identity and position of the substituted amino acid, followed by a letter indicating the identity of the replacement residue; for example, K2A indicates an analog in which Lys2 is replaced with Ala; Animals; Calcium channel; Calcium Channel Blockers - chemical synthesis; Calcium Channel Blockers - chemistry; Calcium Channel Blockers - metabolism; Calcium Channels, N-Type - metabolism; Calcium Channels, P-Type - metabolism; Calcium Channels, Q-Type - metabolism; Cerebellum - metabolism; Chromatography, High Pressure Liquid; Circular Dichroism; Disulfides - chemistry; Fmoc, 9-fluorenylmethoxycarbonyl; GSH, reduced glutathione; GSSG, oxidized glutathione; GVIA, ω-conotoxin GVIA; HPLC, high performance liquid chromatography; In Vitro Techniques; Intracellular Membranes - physiology; Ion Channel Gating; MALDI-TOF-MS, matrix assisted laser desorption/ionization time-of-flight mass spectrometry; Models, Molecular; Molecular Sequence Data; MVIIA, ω-conotoxin MVIIA; MVIIC, ω-conotoxin MVIIC; ODS, octadecylsilane; omega-Conotoxins - chemical synthesis; omega-Conotoxins - chemistry; omega-Conotoxins - metabolism; Protein Binding; Rats; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Structure-Activity Relationship; TFA, trifluoroacetic acid; ω-Conotoxin MVIIC; Ala-scanning; GSH, reduced glutathione; GSSG, oxidized glutathione; Calcium channel; MALDI-TOF-MS, matrix assisted laser desorption/ionization time-of-flight mass spectrometry; HPLC, high performance liquid chromatography; GVIA, ω-conotoxin GVIA; [ 125I]GVIA, [ 125I]ω-conotoxin GVIA; MVIIC, ω-conotoxin MVIIC; MVIIA, ω-conotoxin MVIIA; ω-Conotoxin MVIIC; ODS, octadecylsilane; [ 125I]MVIIC, [ 125I][Nle 12]ω-conotoxin MVIIC; Analogs are designated by a letter and number indicating the identity and position of the substituted amino acid, followed by a letter indicating the identity of the replacement residue; for example, K2A indicates an analog in which Lys 2 is replaced with Ala; Fmoc, 9-fluorenylmethoxycarbonyl; TFA, trifluoroacetic acid
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(00)01263-1

ω-Conotoxin MVIIC binds to P/Q-type calcium channels with high affinity and N-type channels with low affinity. To reveal the residues essential for subtype selectivity, we synthesized Ala-scanning analogs of MVIIC. Binding assays using rat cerebellar P 2 membranes suggested that Thr 11, Tyr 13 and Lys 2 are essential for binding to both N- and P/Q-type channels, whereas Lys 4 and Arg 22 are important for binding to P/Q-type channels. These results suggest that MVIIC interacts with P/Q-type channels via a large surface, in good agreement with previous observations using chimeric analogs.