These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effect of pH on stability of sarcoplasmic reticulum calcium pump in rabbit heart.
    Author: Xu A, Narayanan N, Samson SE, Grover AK.
    Journal: Mol Cell Biochem; 1993 Sep 08; 126(1):87-91. PubMed ID: 8107693.
    Abstract:
    The sarcoplasmic reticulum (SR) membranes isolated from rabbit heart were preincubated at pH 6.8 or 7.8 and their Ca2+ pump properties were compared at pH 6.8. The ATP-dependent azide insensitive oxalate-stimulated Ca2+ uptake was reduced more rapidly from the membranes preincubated at 37 degrees C at pH 7.8 than from those preincubated at pH 6.8. The Ca(2+)-Mg(2+)-ATPase, and the Ca(2+)-dependent formation of 110 kDa acylphosphate were also inhibited by the preincubation at the higher pH. Including 1 mM DTT in the preincubation medium reduced the inactivation. The preincubation at 37 degrees C in the presence or absence of DTT caused membranes to become more leaky as the loss of Ca2+ uptake was more rapid than that of ATPase or the acylphosphate formation. The loss of these activities was not accompanied by a breakdown of the protein as monitored in Western blots. It is hypothesized that the SR Ca2+ pump inactivation involves a key-SH group and that the lower pH provides a compensatory protective mechanism for the SR during acidosis.
    [Abstract] [Full Text] [Related] [New Search]