کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1945084 | 1053251 | 2009 | 6 صفحه PDF | دانلود رایگان |

In this work, we compared the effect of K+ on vesicles derived from the longitudinal (LSR) and terminal cisternae (HSR) of rabbit white muscle. In HSR, K+ was found to inhibit both the Ca2+ accumulation and the heat released during ATP hydrolysis by the Ca2+-ATPase (SERCA1). This was not observed in LSR. Valinomycin abolished the HSR Ca2+-uptake inhibition promoted by physiological K+ concentrations, but it did not modify the thermogenic activity of the Ca2+ pump. The results with HSR are difficult to interpret, assuming that a single K+ is binding to either the ryanodine channel or to the Ca2+-ATPase. It is suggested that an increase of K+ in the assay medium alters the interactions among the various proteins found in HSR, thus modifying the properties of both the ryanodine channel and SERCA1.
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1788, Issue 7, July 2009, Pages 1517–1522