کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10796099 | 1052692 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Inhibition of plasma membrane Ca2+-ATPase by CrATP. LaATP but not CrATP stabilizes the Ca2+-occluded state
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کلمات کلیدی
HEPESDTTEGTAPMSFPMCApNPPSarcoplasmic reticulum Ca2+-ATPase - CaCO2 + -ATPase رتیکولار سرپوپلاسمیp-nitrophenyl phosphate - p-نیترفنیل فسفاتOcclusion - اکلوژنdithiothreitol - دیتیوتریتولPlasma membrane Ca2+-ATPase - غشای پلاسما Ca2 + -ATPaseSERCA - قلبLanthanum - لانتانیوم، لانتانChromium - کروم، فلزی سخت و خاکستری رنگ Calcium - کلسیمErythrocyte - گلبول قرمز یا اریتروسیت
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Inhibition of plasma membrane Ca2+-ATPase by CrATP. LaATP but not CrATP stabilizes the Ca2+-occluded state Inhibition of plasma membrane Ca2+-ATPase by CrATP. LaATP but not CrATP stabilizes the Ca2+-occluded state](/preview/png/10796099.png)
چکیده انگلیسی
The bidentate complex of ATP with Cr3+, CrATP, is a nucleotide analog that is known to inhibit the sarcoplasmic reticulum Ca2+-ATPase and the Na+,K+-ATPase, so that these enzymes accumulate in a conformation with the transported ion (Ca2+ and Na+, respectively) occluded from the medium. Here, it is shown that CrATP is also an effective and irreversible inhibitor of the plasma membrane Ca2+-ATPase. The complex inhibited with similar efficiency the Ca2+-dependent ATPase and the phosphatase activities as well as the enzyme phosphorylation by ATP. The inhibition proceeded slowly (T1/2 = 30 min at 37 °C) with a Ki = 28 ± 9 μM. The inclusion of ATP, ADP or AMPPNP in the inhibition medium effectively protected the enzyme against the inhibition, whereas ITP, which is not a PMCA substrate, did not. The rate of inhibition was strongly dependent on the presence of Mg2+ but unaltered when Ca2+ was replaced by EGTA. In spite of the similarities with the inhibition of other P-ATPases, no apparent Ca2+ occlusion was detected concurrent with the inhibition by CrATP. In contrast, inhibition by the complex of La3+ with ATP, LaATP, induced the accumulation of phosphoenzyme with a simultaneous occlusion of Ca2+ at a ratio close to 1.5 mol/mol of phosphoenzyme. The results suggest that the transport of Ca2+ promoted by the plasma membrane Ca2+-ATPase goes through an enzymatic phospho-intermediate that maintains Ca2+ ions occluded from the media. This intermediate is stabilized by LaATP but not by CrATP.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1708, Issue 3, 15 July 2005, Pages 411-419
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1708, Issue 3, 15 July 2005, Pages 411-419
نویسندگان
Otacilio C. Moreira, Priscila F. Rios, Hector Barrabin,