Quantum model for a periodically driven selectivity filter in a K+ ion channel

Autor(es)

Cifuentes, A. A. ^[1] ; Semiao, F. L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS; v. 47, n. 22 NOV 28 2014.
• Citações Web of Science: 4

Resumo

In this work, we present a quantum transport model for the selectivity filter in the KcsA potassium ion channel. This model is fully consistent with the fact that two conduction pathways are involved in the translocation of ions through the filter, and we show that the presence of a second path may actually bring advantages for the filter as a result of quantum interference. To highlight interferences and resonances in the model, we consider the selectivity filter to be driven by a controlled time-dependent external field, which changes the free-energy scenario and consequently the conduction of the ions. In particular, we demonstrate that the two-pathway conduction mechanism is more advantageous for the filter when dephasing in the transient configurations is lower than in the main configurations. As a matter of fact, K+ ions in the main configurations are highly coordinated by oxygen atoms of the filter backbone, and this increases noise. Moreover, we also show that for a wide range of dephasing rates and driving frequencies, the two-pathway conduction used by the filter leads to higher ionic currents than the single-path model. (AU)

• Processo FAPESP: 12/12624-6 - Estudo de um modelo quântico para canais iônicos de potássio
• Beneficiário: Alvaro Andres Cifuentes Garcia
• Modalidade de apoio: Bolsas no Brasil - Mestrado