Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2010 Mar;135(3):261–274. doi: 10.1085/jgp.200910288

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2010 Bruhova and Zhorov

This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).

PMC Copyright notice

Figure 8. — The residual current upon MTSET application correlates with the distance of the MTS atom N⁺_^mC (A and B), but not atom C^β_^mC (C and D) from the pore axis. (A and C) The experimental values of the current inhibition with standard deviations (Zhen et al., 2005) are plotted against the predicted distances of atoms N⁺_^mC (A) or C^β (C) from the pore axis. Data are shown for channels with engineered cysteines in positions i15–i21, i23–i25, and o10. Black dots represent the apparent global minima of channels in which all minimum energy conformations of ^mC side chains are unambiguously oriented in respect to the pore (e.g., inside the pore for channels ^mCⁱ¹⁵ or outside the pore for channels ^mCⁱ¹⁷). Blue dots represent the apparent global minima of the channels in which the ^mC side chain adopts low energy conformations with distinct orientation in respect to the pore (e.g., channels ^mCⁱ¹⁸). A green dot represents a local minimum (within 2 kcal/mol from the apparent global minimum) of a channel in which the ^mC side chain adopts conformations with distinct orientation in respect to the pore (e.g., channels ^mCⁱ¹⁶). Horizontal lines show the N⁺_^mC atom mobility in conformations within 2 kcal/mol from the apparent global minimum (Table S1). Note a smooth decrease of the current inhibition with increase of the distance between the MTS nitrogen and the pore axis. The current inhibition of ∼20% at distances >16 Å corresponds to MTSET block of the “control channel,” in which eight native cysteines in the α₁ subunit have been replaced with alanines and no engineered cysteines have been introduced (Zhen et al., 2005). (B and D) The extracellular view of Ca_v2.1, with atoms ^mC_N⁺ (B) and ^mC_C^β (D) shown as spheres. P loops are omitted for clarity. Yellow and blue spheres represent the respective atoms in the channels, which are inhibited by MTSET by >30 and ≤30%, respectively. (B) In most of the channels, which are strongly inhibited by MTSET, the yellow-colored ammonium nitrogen (^mC_N⁺) is located either close to the pore axis or at the inner surface of the pore, whereas in the channels, which are weakly inhibited by MTSET, the blue-colored ammonium nitrogen is not inside the pore. (D) Location of β carbons does not correlate with the level of current inhibition by MTSET. Both yellow and blue spheres are randomly distributed at different sides of the inner helices.