Conformational state-dependent anion binding in prestin: evidence for allosteric modulation.

ABSTRACT: Outer hair cells boost auditory performance in mammals. This amplification relies on an expansive array of intramembranous molecular motors, identified as prestin, that drive somatic electromotility. By measuring nonlinear capacitance, the electrical signature of electromotility, we are able to assess prestin's conformational state and interrogate the effectiveness of anions on prestin's activity. We find that the affinity of anions depends on the state of prestin that we set with a variety of perturbations (in membrane tension, temperature, and voltage), and that movement into the expanded state reduces the affinity of prestin for anions. These data signify that anions work allosterically on prestin. Consequently, anions are released from prestin's binding site during expansion, i.e., dur

SUBMITTER: Song L 

PROVIDER: S-EPMC2814207 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature