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: [Retarded conformational transitions in muscle glycogen phosphorylase b induced by specific ligands].
    Author: Kurganov BI, Shchors EI, Livanova NB, Eronina TB, Chebotareva NA.
    Journal: Biokhimiia; 1994 Apr; 59(4):559-67. PubMed ID: 8018778.
    Abstract:
    The effect of specific ligands on the initial rate of muscle glycogen phosphorylase b digestion by trypsin has been studied. The kinetics of tryptic proteolysis were followed by measuring the decrease in phosphorylase b fluorescence intensity at 335 nm (excitation at 290 nm). The kinetic curves were linear at least in the region 0-400 s (0.02 M HEPES, pH 6.8; 37 degrees C). An allosteric activator (AMP) and allosteric inhibitors (flavins) protected the enzyme from tryptic digestion when trypsin was added to the enzyme preincubated with the ligand. Differences were found between the kinetic curves of trypsinolysis initiated by addition of the trypsin-ligand mixture to phosphorylase b an by addition of trypsin to the enzyme preincubated with the ligand for 10 min. It is concluded that the specific ligands under study (AMP, flavins, and the substrate--glucose 1-phosphate) induce relatively slow conformational changes in the phosphorylase b molecule with the half-conversion time of several minutes.
    [Abstract] [Full Text] [Related] [New Search]