scholarly journals Characterization of a C-type natriuretic peptide (CNP-39)-formed cation-selective channel from platypus (Ornithorhynchus anatinus) venom

1999 ◽  
Vol 518 (2) ◽  
pp. 359-369 ◽  
Author(s):  
Joseph I. Kourie
Keyword(s):  
Natriuretic Peptide ◽  
Ornithorhynchus Anatinus ◽  
Selective Channel ◽  
Cation Selective Channel

scholarly journals Cation-Selective Channel Regulated by Anions According to Their Hofmeister Ranking

2017 ◽  
Vol 56 (13) ◽  
pp. 3506-3509 ◽  
Author(s):  
Philip A. Gurnev ◽  
Torri C. Roark ◽  
Horia I. Petrache ◽  
Alexander J. Sodt ◽  
Sergey M. Bezrukov
Keyword(s):  
Selective Channel ◽  
Cation Selective Channel

Characterization of a newly found stretch-activated KCa,ATP channel in cultured chick ventricular myocytes

1999 ◽  
Vol 276 (6) ◽  
pp. H1827-H1838 ◽  
Author(s):  
Takashi Kawakubo ◽  
Keiji Naruse ◽  
Tatsuaki Matsubara ◽  
Nigishi Hotta ◽  
Masahiro Sokabe
Keyword(s):  
Single Channel ◽  
Ventricular Myocytes ◽  
Heart Cells ◽  
Patch Clamp Technique ◽  
Selective Channel ◽  
New Type ◽  
Inside Out ◽  
Ion Selectivities ◽  
Channel Type

With the use of the patch-clamp technique, five kinds of stretch-activated (SA) ion channels were identified on the basis of their single-channel conductances and ion selectivities in cultured chick ventricular myocytes. Because a high-conductance K+-selective channel predominated among these channels, we concentrated on characterizing its properties mostly using excised inside-out patches. With 145 mM KCl solution in the pipette and the bath, the channel had a conductance of 199.8 ± 8.2 pS ( n = 22). The ion selectivities among K+, Na+, Ca2+, and Cl− as estimated from their permeability ratios were P Na/ P K= 0.03, P Ca/ P K= 0.025, and P Cl/ P K= 0.026. The probability of the channel being open (Po) increased with the Ca2+concentration in the bath ([Ca2+]b; dissociation constant K d = 0.51 μM at +30 mV) and membrane potential (voltage at half-maximal Po= 39.4 mV at 0.35 μM [Ca2+]b). The channel was blocked by gadolinium, tetraethylammonium, and charybdotoxin from the extracellular surface and, consequently, was identified as a Ca2+-activated K+(KCa) channel type. The channel was also reversibly activated by ATP applied to the intracellular surface ( K d = 0.74 mM at 0.10 μM [Ca2+]bat +30 mV). From these data taken together, we concluded that the channel is a new type of KCachannel that could be designated as an “SA KCa,ATP channel.” To our knowledge, this is the first report of KCa channel in heart cells.

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