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

. 2009 Sep;134(3):243–258. doi: 10.1085/jgp.200910255

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

© 2009 Liu et al.

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.jgp.org/misc/terms.shtml). 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 6. — Double mutations of D646 and E636 abrogate proton block. (A and B) Examples of single-channel currents from the double mutant D646N/E636Q, showing little changes in the unitary current amplitudes with changes in extracellular pH at several ionic concentrations ([K⁺] = 25, 100, 500, and 1,000 mM). (A) Holding potential of +60 mV. (B) Holding potential of −60 mV. Solutions were symmetrical on both sides of membranes. (C and D) Plots of unitary current amplitudes versus [K⁺] at the indicated pH. (C) −60 mV. (D) +60 mV. Solid lines indicate double mutant, and dashed lines are for wild type. The unitary current amplitudes of the double mutant were similar to those of wild type at low pH and were independent of extracellular pH changes over a broad range of ionic concentrations (25–2,000 mM). The mutant did not show a detectable expression in oocytes. All recordings were from HEK293 cells.