English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The tightly coupled, one-for-one exchange of anions mediated by the human red blood cell AE1 anion-exchange protein involves a ping-pong mechanism, in which AE1 alternates between a state with the anion-binding site facing inward toward the cytoplasm (Ei) and a state with the site facing outward toward the external medium (Eo). The conformational shift (Ei &lt;--&gt; Eo) is only permitted when a suitable substrate such as Cl(-) or HCO(3)(-) (B(-)) is bound. With no anions bound, or with Cl(-) bound, far more AE1 molecules are in the inward-facing than the outward-facing forms (Ei Eo, ECli EClo). We have constructed a model for CI(-)-B(-) exchange based on Cl(-)-Cl(-) and B(-)-B(-) exchange data, and have used it to predict the heteroexchange flux under extremely asymmetric conditions, with either all Cl(-) inside and all B(-) outside (Cli-Bo) or vice versa (Bi-Clo). The experimental values of the ratio of the exchange rate for Bi-Clo to that for Cli-Bo are only compatible with the model if the asymmetry of bicarbonate-loaded sites (A(B) = EBo/EBi) &gt; 10, the opposite of the asymmetry for unloaded or Cl-loaded sites. Furthermore, the Eo form has a higher affinity for HCO(3)(-) than for Cl(-), whereas the Ei form has a higher affinity for Cl(-). The fact that this "passive" system exhibits changes in substrate selectivity with site orientation ("sidedness"), a characteristic usually associated with energy-coupled "active" pumps, suggests that changes in affinity with changes in sidedness are a more general property of transport proteins than previously thought.

Substrate-dependent reversal of anion transport site orientation in the human red blood cell anion-exchange protein, AE1