English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Phosphorylation of the sarcoplasmic calcium-activated adenosinetriphosphatase as studied by 31P nuclear magnetic resonance

MPS-Authors
/persons/resource/persons213412

Sontheimer,  Gerhard M.
Max Planck Institute for Medical Research, Max Planck Society;

/persons/resource/persons93660

Kalbitzer,  Hans Robert
Emeritus Group Biophysics, Max Planck Institute for Medical Research, Max Planck Society;

/persons/resource/persons93324

Hasselbach,  Wilhelm
Emeritus Group Biophysics, Max Planck Institute for Medical Research, Max Planck Society;

Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Sontheimer, G. M., Kalbitzer, H. R., & Hasselbach, W. (1987). Phosphorylation of the sarcoplasmic calcium-activated adenosinetriphosphatase as studied by 31P nuclear magnetic resonance. Biochemistry, 26(10), 2701-2706. doi:10.1021/bi00384a008.


Cite as: http://hdl.handle.net/21.11116/0000-0007-E5BC-3
Abstract
A reinvestigation of a study of Fossel et al. [Fossel, E. T., Post, R. L., O'Hara, D.S., & Smith, T. W. (1981) Biochemistry 20, 7215-7219] in which the 31P nuclear magnetic resonance (NMR) signal of the phosphointermediate of the sarcoplasmic (Ca2+, Mg2+)-ATPase has been identified shows that the signal they describe most probably originates from free Mg . ATP but not from the phosphoenzyme itself. It was possible to detect the 31P NMR signal of the phosphoenzyme in peptic fragments of sarcoplasmic ATPase phosphorylated either by ATP or by inorganic phosphate. The two products exhibit the same spectral characteristics in 31P NMR, implying that most probably both reaction pathways yield the same chemical product. Chemical shifts at low pH (-6.5 ppm) and high pH (-1.4 ppm) of the phosphoryl group are indicative of a beta-phosphoaspartyl moiety, thus confirming independently the results from chemical analysis. The relatively low pK value of 4.3 of the phosphoryl group suggests an interaction with a positively charged group of the enzyme.