Multiple Residues in the P-Region and M2 of Murine Kir 2.1 Regulate Blockage by External Ba2+

Abstract

for a W T-Y145L dimer, and 267μM for Y145F. Mutant channels T141A and S165L exhibit a reduced affinity together with a large reduction in the rate of blockage. In S165L, blockage proceeds with a double exponential time course, suggestive of more than one blocking site. The double mutation T141A/S165L dramatically reduced affinity for Ba 2＋ , also showing two components with very different time courses. Mutants D172K and D172R (lining the central, aqueous cavity of the channel) showed both a decreased affinity to Ba 2＋ and a decrease in the on transition rate constant (kon). These results imply that residues stabilising the cytoplasmic end of the selectivity filter (T141, S165) and in the central cavity (D172) are major determinants of high affinity Ba 2＋ blockage in Kir 2.1.

Directed Self-Assembly of C4-Symmetric, Oxidovanadate-Centered, Vanadyl(V) Quadruplexes for Ba2+- and Hg2+-Specific Recognition, Transport, and Recovery

“…On the other hand, high K + -transport selectivity from an aqueous phase containing four different alkali metal metavanadates was observed for the directed assembly of 2X to form 2Cl q - K or 2Br q - K with a unique square planar complexation. , Their 51 V NMR spectroscopic analyses revealed that all of these clusters show two distinctive signals in 1:4 ratios in CDCl 3 corresponding to the central oxidovanadate and four flanking oxidovanadium units, respectively. This encapsulation behavior is reminiscent of G-quartets and K + -channel protein (i.e., KcsA − ) binding motifs. Therefore, the metal ion binding domain of a given tetrameric cluster increases with decreasing size of the R′ substituent in the salicylidene template and is modulable with a judicious choice of R′.…”

Chronic Propafenone Application Increases Functional KIR2.1 Expression In Vitro

“…K IR 2.1-D172R and D172H mutant constructs were obtained from Dr. So (Seoul National University, College of Medicine, Republic of Korea), and functional characteristics have been described before [ 78 ]. A K IR 2.1-R312H mutant construct was obtained from Dr. Bendahhou (Université Côte d’Azur, France), and functional characteristics have been described recently [ 79 ].…”