Cargando…
Fluctuation of actin sliding over myosin thick filaments in vitro
It is customarily thought that myosin motors act as independent force-generators in both isotonic unloaded shortening as well as isometric contraction of muscle. We tested this assumption regarding unloaded shortening, by analyzing the fluctuation of the actin sliding movement over long native thick...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Biophysical Society of Japan (BSJ)
2005
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5036633/ https://www.ncbi.nlm.nih.gov/pubmed/27857552 http://dx.doi.org/10.2142/biophysics.1.45 |
_version_ | 1782455587936665600 |
---|---|
author | Noda, Naoki Imafuku, Yasuhiro Yamada, Akira Tawada, Katsuhisa |
author_facet | Noda, Naoki Imafuku, Yasuhiro Yamada, Akira Tawada, Katsuhisa |
author_sort | Noda, Naoki |
collection | PubMed |
description | It is customarily thought that myosin motors act as independent force-generators in both isotonic unloaded shortening as well as isometric contraction of muscle. We tested this assumption regarding unloaded shortening, by analyzing the fluctuation of the actin sliding movement over long native thick filaments from molluscan smooth muscle in vitro. This analysis is based on the prediction that the effective diffusion coefficient of actin, a measure of the fluctuation, is proportional to the inverse of the number of myosin motors generating the sliding movement of an actin filament, hence proportional to the inverse of the actin length, when the actions of the motors are stochastic and statistically independent. Contrary to this prediction, we found the effective diffusion coefficient to be virtually independent of, and thus not proportional to, the inverse of the actin length. This result shows that the myosin motors are not independent force-generators when generating the continuous sliding movement of actin in vitro and that the sliding motion is a macroscopic manifestation of the cooperative actions of the microscopic ensemble motors. |
format | Online Article Text |
id | pubmed-5036633 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2005 |
publisher | The Biophysical Society of Japan (BSJ) |
record_format | MEDLINE/PubMed |
spelling | pubmed-50366332016-11-17 Fluctuation of actin sliding over myosin thick filaments in vitro Noda, Naoki Imafuku, Yasuhiro Yamada, Akira Tawada, Katsuhisa Biophysics (Nagoya-shi) Articles It is customarily thought that myosin motors act as independent force-generators in both isotonic unloaded shortening as well as isometric contraction of muscle. We tested this assumption regarding unloaded shortening, by analyzing the fluctuation of the actin sliding movement over long native thick filaments from molluscan smooth muscle in vitro. This analysis is based on the prediction that the effective diffusion coefficient of actin, a measure of the fluctuation, is proportional to the inverse of the number of myosin motors generating the sliding movement of an actin filament, hence proportional to the inverse of the actin length, when the actions of the motors are stochastic and statistically independent. Contrary to this prediction, we found the effective diffusion coefficient to be virtually independent of, and thus not proportional to, the inverse of the actin length. This result shows that the myosin motors are not independent force-generators when generating the continuous sliding movement of actin in vitro and that the sliding motion is a macroscopic manifestation of the cooperative actions of the microscopic ensemble motors. The Biophysical Society of Japan (BSJ) 2005-06-16 /pmc/articles/PMC5036633/ /pubmed/27857552 http://dx.doi.org/10.2142/biophysics.1.45 Text en 2005 © The Biophysical Society of Japan |
spellingShingle | Articles Noda, Naoki Imafuku, Yasuhiro Yamada, Akira Tawada, Katsuhisa Fluctuation of actin sliding over myosin thick filaments in vitro |
title | Fluctuation of actin sliding over myosin thick filaments in vitro |
title_full | Fluctuation of actin sliding over myosin thick filaments in vitro |
title_fullStr | Fluctuation of actin sliding over myosin thick filaments in vitro |
title_full_unstemmed | Fluctuation of actin sliding over myosin thick filaments in vitro |
title_short | Fluctuation of actin sliding over myosin thick filaments in vitro |
title_sort | fluctuation of actin sliding over myosin thick filaments in vitro |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5036633/ https://www.ncbi.nlm.nih.gov/pubmed/27857552 http://dx.doi.org/10.2142/biophysics.1.45 |
work_keys_str_mv | AT nodanaoki fluctuationofactinslidingovermyosinthickfilamentsinvitro AT imafukuyasuhiro fluctuationofactinslidingovermyosinthickfilamentsinvitro AT yamadaakira fluctuationofactinslidingovermyosinthickfilamentsinvitro AT tawadakatsuhisa fluctuationofactinslidingovermyosinthickfilamentsinvitro |