Conformational changes of F-actin in myosin-free ghost single fibre induced by either phosphorylated or dephosphorylated heavy meromyosin

Irena Kâkol, Yurii S. Borovikov, Danuta Szczesna-Cordary, Valentina P. Kirillina, Dimitrii I. Levitsky

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The changes in F-actin conformation of myosin-free single ghost fibre induced by binding of phosphorylated or dephosphorylated heavy meromyosin have been studied by measuring polarized fluorescence of F-actin intrinsic tryptophan and of phalloidin-rhodamin bound to F-actin. The changes of polarization of both fluorescences were found to be dependent on low or high Ca2+ concenration and on the phosphorylated or dephosphorylated form of heavy meromyosin. Computer analysis of polarized fluorescence has shown that binding of phosphorylated heavy meromyosin with divalent ion binding sites saturated with Mg2+ (in the presence of 1 mM MgCl2 and 1 mM EGTA) and dephosphorylated heavy meromyosin with divalent ion binding sites saturated with Ca2+ (in the presence of 1 mM MgCl2 and 0.1 mM Ca2+) decreases the angles of emission and absorption dipoles and the angle between the F-actin axis and the fibre axis, thus suggesting that F-actin in ghost fibre becomes more flexible. On the other hand, the above-mentioned angles increase when phosphorylated heavy meromyosin at high and dephosphorylated heavy meromyosin at low Ca2+ concentration were bound to thin filaments, thus showing the decrease of F-actin flexibility under these conditions.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalBiochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
Volume913
Issue number1
DOIs
StatePublished - May 27 1987
Externally publishedYes

Fingerprint

Myosin Subfragments
Myosins
Actins
Fibers
Magnesium Chloride
Fluorescence
Binding Sites
Ions
Phalloidine
Fluorescence Polarization
Egtazic Acid
Tryptophan
Conformations
Polarization

Keywords

  • F-actin
  • Fluorescence, polarized
  • Ghost fibre, myosin-free
  • Heavy meromyosin, (de)phosphorylated
  • Myosin

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology
  • Structural Biology

Cite this

Conformational changes of F-actin in myosin-free ghost single fibre induced by either phosphorylated or dephosphorylated heavy meromyosin. / Kâkol, Irena; Borovikov, Yurii S.; Szczesna-Cordary, Danuta; Kirillina, Valentina P.; Levitsky, Dimitrii I.

In: Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular, Vol. 913, No. 1, 27.05.1987, p. 1-9.

Research output: Contribution to journalArticle

@article{87f71014161e47c6885401826425db3e,
title = "Conformational changes of F-actin in myosin-free ghost single fibre induced by either phosphorylated or dephosphorylated heavy meromyosin",
abstract = "The changes in F-actin conformation of myosin-free single ghost fibre induced by binding of phosphorylated or dephosphorylated heavy meromyosin have been studied by measuring polarized fluorescence of F-actin intrinsic tryptophan and of phalloidin-rhodamin bound to F-actin. The changes of polarization of both fluorescences were found to be dependent on low or high Ca2+ concenration and on the phosphorylated or dephosphorylated form of heavy meromyosin. Computer analysis of polarized fluorescence has shown that binding of phosphorylated heavy meromyosin with divalent ion binding sites saturated with Mg2+ (in the presence of 1 mM MgCl2 and 1 mM EGTA) and dephosphorylated heavy meromyosin with divalent ion binding sites saturated with Ca2+ (in the presence of 1 mM MgCl2 and 0.1 mM Ca2+) decreases the angles of emission and absorption dipoles and the angle between the F-actin axis and the fibre axis, thus suggesting that F-actin in ghost fibre becomes more flexible. On the other hand, the above-mentioned angles increase when phosphorylated heavy meromyosin at high and dephosphorylated heavy meromyosin at low Ca2+ concentration were bound to thin filaments, thus showing the decrease of F-actin flexibility under these conditions.",
keywords = "F-actin, Fluorescence, polarized, Ghost fibre, myosin-free, Heavy meromyosin, (de)phosphorylated, Myosin",
author = "Irena K{\^a}kol and Borovikov, {Yurii S.} and Danuta Szczesna-Cordary and Kirillina, {Valentina P.} and Levitsky, {Dimitrii I.}",
year = "1987",
month = "5",
day = "27",
doi = "10.1016/0167-4838(87)90225-1",
language = "English",
volume = "913",
pages = "1--9",
journal = "Biochimica et Biophysica Acta - Proteins and Proteomics",
issn = "1570-9639",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Conformational changes of F-actin in myosin-free ghost single fibre induced by either phosphorylated or dephosphorylated heavy meromyosin

AU - Kâkol, Irena

AU - Borovikov, Yurii S.

AU - Szczesna-Cordary, Danuta

AU - Kirillina, Valentina P.

AU - Levitsky, Dimitrii I.

PY - 1987/5/27

Y1 - 1987/5/27

N2 - The changes in F-actin conformation of myosin-free single ghost fibre induced by binding of phosphorylated or dephosphorylated heavy meromyosin have been studied by measuring polarized fluorescence of F-actin intrinsic tryptophan and of phalloidin-rhodamin bound to F-actin. The changes of polarization of both fluorescences were found to be dependent on low or high Ca2+ concenration and on the phosphorylated or dephosphorylated form of heavy meromyosin. Computer analysis of polarized fluorescence has shown that binding of phosphorylated heavy meromyosin with divalent ion binding sites saturated with Mg2+ (in the presence of 1 mM MgCl2 and 1 mM EGTA) and dephosphorylated heavy meromyosin with divalent ion binding sites saturated with Ca2+ (in the presence of 1 mM MgCl2 and 0.1 mM Ca2+) decreases the angles of emission and absorption dipoles and the angle between the F-actin axis and the fibre axis, thus suggesting that F-actin in ghost fibre becomes more flexible. On the other hand, the above-mentioned angles increase when phosphorylated heavy meromyosin at high and dephosphorylated heavy meromyosin at low Ca2+ concentration were bound to thin filaments, thus showing the decrease of F-actin flexibility under these conditions.

AB - The changes in F-actin conformation of myosin-free single ghost fibre induced by binding of phosphorylated or dephosphorylated heavy meromyosin have been studied by measuring polarized fluorescence of F-actin intrinsic tryptophan and of phalloidin-rhodamin bound to F-actin. The changes of polarization of both fluorescences were found to be dependent on low or high Ca2+ concenration and on the phosphorylated or dephosphorylated form of heavy meromyosin. Computer analysis of polarized fluorescence has shown that binding of phosphorylated heavy meromyosin with divalent ion binding sites saturated with Mg2+ (in the presence of 1 mM MgCl2 and 1 mM EGTA) and dephosphorylated heavy meromyosin with divalent ion binding sites saturated with Ca2+ (in the presence of 1 mM MgCl2 and 0.1 mM Ca2+) decreases the angles of emission and absorption dipoles and the angle between the F-actin axis and the fibre axis, thus suggesting that F-actin in ghost fibre becomes more flexible. On the other hand, the above-mentioned angles increase when phosphorylated heavy meromyosin at high and dephosphorylated heavy meromyosin at low Ca2+ concentration were bound to thin filaments, thus showing the decrease of F-actin flexibility under these conditions.

KW - F-actin

KW - Fluorescence, polarized

KW - Ghost fibre, myosin-free

KW - Heavy meromyosin, (de)phosphorylated

KW - Myosin

UR - http://www.scopus.com/inward/record.url?scp=0023279088&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023279088&partnerID=8YFLogxK

U2 - 10.1016/0167-4838(87)90225-1

DO - 10.1016/0167-4838(87)90225-1

M3 - Article

C2 - 3555620

AN - SCOPUS:0023279088

VL - 913

SP - 1

EP - 9

JO - Biochimica et Biophysica Acta - Proteins and Proteomics

JF - Biochimica et Biophysica Acta - Proteins and Proteomics

SN - 1570-9639

IS - 1

ER -