HOMEPRODUCTSSERVICESCOMPANYCONTACTFAQResearchDictionaryPharmaMobileSign Up FREE or Login

The motor protein myosin-I produces its working stroke in two steps.

Abstract
Many types of cellular motility, including muscle contraction, are driven by the cyclical interaction of the motor protein myosin with actin filaments, coupled to the breakdown of ATP. It is thought that myosin binds to actin and then produces force and movement as it 'tilts' or 'rocks' into one or more subsequent, stable conformations. Here we use an optical-tweezers transducer to measure the mechanical transitions made by a single myosin head while it is attached to actin. We find that two members of the myosin-I family, rat liver myosin-I of relative molecular mass 130,000 (M(r) 130K) and chick intestinal brush-border myosin-I, produce movement in two distinct steps. The initial movement (of roughly 6 nanometres) is produced within 10 milliseconds of actomyosin binding, and the second step (of roughly 5.5 nanometres) occurs after a variable time delay. The duration of the period following the second step is also variable and depends on the concentration of ATP. At the highest time resolution possible (about 1 millisecond), we cannot detect this second step when studying the single-headed subfragment-1 of fast skeletal muscle myosin II. The slower kinetics of myosin-I have allowed us to observe the separate mechanical states that contribute to its working stroke.
AuthorsC Veigel, L M Coluccio, J D Jontes, J C Sparrow, R A Milligan, J E Molloy
JournalNature (Nature) Vol. 398 Issue 6727 Pg. 530-3 (Apr 8 1999) ISSN: 0028-0836 [Print] ENGLAND
PMID10206648 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
Chemical References
  • Actins
  • Molecular Motor Proteins
  • Myo1b protein, rat
  • Adenosine Triphosphate
  • Actomyosin
  • Myosin Type I
  • Myosins
Topics
  • Actins (physiology)
  • Actomyosin (physiology)
  • Adenosine Triphosphate (metabolism)
  • Animals
  • Biomechanical Phenomena
  • In Vitro Techniques
  • Models, Biological
  • Molecular Motor Proteins (physiology)
  • Myosin Type I
  • Myosins (genetics, physiology)
  • Protein Binding
  • Rats
  • Transducers

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 network!


Choose Username:
Email:
Password:
Verify Password: