Kinetics of Ca2+ Binding to the SR Ca-ATPase in the E1 State


Dateien zu dieser Ressource

Prüfsumme: MD5:5b1aa7ffe4df68c97d69c87ec3f63d7f

PEINELT, Christine, Hans-Jürgen APELL, 2005. Kinetics of Ca2+ Binding to the SR Ca-ATPase in the E1 State. In: Biophysical Journal. 89(4), pp. 2427-2433. ISSN 0006-3495. Available under: doi: 10.1529/biophysj.105.068411

@article{Peinelt2005Kinet-8215, title={Kinetics of Ca2+ Binding to the SR Ca-ATPase in the E1 State}, year={2005}, doi={10.1529/biophysj.105.068411}, number={4}, volume={89}, issn={0006-3495}, journal={Biophysical Journal}, pages={2427--2433}, author={Peinelt, Christine and Apell, Hans-Jürgen} }

2005 Kinetics of Ca2+ Binding to the SR Ca-ATPase in the E1 State Peinelt, Christine 2011-03-24T17:41:29Z eng terms-of-use 2011-03-24T17:41:29Z application/pdf First publ. in: Biophysical Journal 89 (2005), pp. 2427-2433 The time-resolved kinetics of Ca2+ binding to the SR Ca-ATPase in the E1 state was investigated by Ca2+-concentration jump experiments. Ca2+ was released by an ultraviolet-light flash from caged calcium, and charge movements in the membrane domain of the ion pumps were detected by the fluorescent styryl dye 2BITC. The partial reaction (H3E1 {leftrightarrow}) E1 {leftrightarrow} CaE1 {leftrightarrow} Ca2E1 can be characterized by two time constants, {tau}1 and {tau}2, both of which are not significantly Ca2+-concentration-dependent and only weakly pH-dependent at pH < 7.5. Both time constants differ by a factor of ~50 (4.7 vs. 200 ms). The weak substrate-dependence indicates that the rate-limiting process is not related to Ca2+ migration through the access channel and ion binding to the binding sites but to conformational rearrangements preceding the ion movements. The high activation energy obtained for both processes, 42.3 kJ mol 1 and 60.3 kJ mol 1 at pH 7.2, support this concept. Transient binding of Ca ions to the loop L67 and a movement of the Ca-loaded loop are discussed as a mechanism that facilitates the entrance of both Ca ions into the access channel to the ion-binding sites. Apell, Hans-Jürgen Apell, Hans-Jürgen Peinelt, Christine

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

Kinetics_of_Ca2_Binding_to_the_SR_Ca_ATPase_in_the_E1_State.pdf 167

Das Dokument erscheint in:

terms-of-use Solange nicht anders angezeigt, wird die Lizenz wie folgt beschrieben: terms-of-use

KOPS Suche


Mein Benutzerkonto