In Voltage-Activated Channels, Preferential Ion Selectivity for Calcium Over Sodium

question 21

Multiple Choice

In voltage-activated channels, preferential ion selectivity for calcium over sodium is governed by which of these factors?

• A) Cumulative negative charge of amino acids that line the pore
• B) An ensemble mix of negative, positive, and neutral amino acids that line the pore
• C) Glutamine residues at four positions that line the pore
• D) Aspartate followed by glutamate-that pattern repeated twice-at four key positions that line the pore
• E) Characteristic features of the P-loop

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