HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Electron microscopic recording of myosin head power stroke in hydrated myosin filaments.

Abstract
Muscle contraction results from cyclic attachment and detachment between myosin heads and actin filaments, coupled with ATP hydrolysis. Despite extensive studies, however, the amplitude of myosin head power stroke still remains to be a mystery. Using the gas environmental chamber, we have succeeded in recording the power stroke of position-marked myosin heads in hydrated mixture of actin and myosin filaments in a nearly isometric condition, in which myosin heads do not produce gross myofilament sliding, but only stretch adjacent elastic structures. On application of ATP, individual myosin heads move by ~3.3 nm at the distal region, and by ~2.5 nm at the proximal region of myosin head catalytic domain. After exhaustion of applied ATP, individual myosin heads return towards their initial position. At low ionic strength, the amplitude of myosin head power stroke increases to >4 nm at both distal and proximal regions of myosin heads catalytic domain, being consistent with the report that the force generated by individual myosin heads in muscle fibers is enhanced at low ionic strength. The advantages of the present study over other in vitro motility assay systems, using myosin heads detached from myosin filaments, are discussed.
AuthorsHaruo Sugi, Shigeru Chaen, Tsuyoshi Akimoto, Hiroki Minoda, Takuya Miyakawa, Yumiko Miyauchi, Masaru Tanokura, Seiryo Sugiura
JournalScientific reports (Sci Rep) Vol. 5 Pg. 15700 (Oct 26 2015) ISSN: 2045-2322 [Electronic] England
PMID26498981 (Publication Type: Journal Article)
Chemical References
  • Actins
  • Adenosine Triphosphate
  • Myosins
Topics
  • Actin Cytoskeleton (chemistry, metabolism)
  • Actins (chemistry, metabolism)
  • Adenosine Triphosphate (metabolism)
  • Animals
  • Catalytic Domain
  • Male
  • Microscopy, Electron
  • Muscle Contraction (physiology)
  • Myosins (chemistry, metabolism, ultrastructure)
  • Osmolar Concentration
  • Rabbits

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: