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 ethylene glycol on the interaction of different myosin subfragment 1.nucleotide complexes with actin.
    Author: Mushtaq E, Greene LE.
    Journal: Biochemistry; 1989 Jul 25; 28(15):6478-82. PubMed ID: 2551376.
    Abstract:
    To elucidate the structure of the cross-bridge intermediates in the actomyosin ATPase cycle, several laboratories have added both ethylene glycol and AMP-PNP to muscle fibers. These studies suggested that ethylene glycol shifts the structure of myosin.AMP-PNP toward the weak-binding conformation, i.e., toward the structure of myosin.ATP. Since only the weak-binding conformation of myosin subfragment 1 (S-1) binds with no apparent cooperativity to the troponin-tropomyosin-actin complex (regulated actin), we used this as a probe to examine the conformation of various S-1.nucleotide complexes in ethylene glycol. Our results show that ethylene glycol markedly weakens the binding strength of S-1, S-1.ADP, and S-1.AMP-PNP to actin but has almost no effect on the binding strength of S-1.ATP. As in muscle fibers, at 40% ethylene glycol, the binding strength of S-1.AMP-PNP to actin becomes very similar to the binding strength of S-1.ATP. In the presence of troponin-tropomyosin, the binding of S-1.AMP-PNP to actin shows no apparent cooperativity in 40% ethylene glycol. Therefore, our results confirm that ethylene glycol shifts the structure of the myosin.AMP-PNP toward the weak-binding conformation. However, our results also suggest that ethylene glycol has a direct effect on the regulated actin complex. This is shown by the fact that ethylene glycol markedly increases the cooperative binding of S-1.ADP to regulated actin both in the presence and in the absence of Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]