Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein

Richard Niederman, P. C. Amrein, J. Hartwig

Research output: Contribution to journalArticle

Abstract

Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0° and 90°. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.

Original languageEnglish (US)
Pages (from-to)1400-1413
Number of pages14
JournalJournal of Cell Biology
Volume96
Issue number5
StatePublished - 1983

Fingerprint

Microfilament Proteins
Actin Cytoskeleton
Actins
Gels
Computer Graphics
Cytoskeleton
Macrophages
Electrons
Muscles
Proteins

ASJC Scopus subject areas

  • Cell Biology

Cite this

Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein. / Niederman, Richard; Amrein, P. C.; Hartwig, J.

In: Journal of Cell Biology, Vol. 96, No. 5, 1983, p. 1400-1413.

Research output: Contribution to journalArticle

@article{4f742629eca94beba17999d7abe38b6a,
title = "Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein",
abstract = "Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0° and 90°. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.",
author = "Richard Niederman and Amrein, {P. C.} and J. Hartwig",
year = "1983",
language = "English (US)",
volume = "96",
pages = "1400--1413",
journal = "Journal of Cell Biology",
issn = "0021-9525",
publisher = "Rockefeller University Press",
number = "5",

}

TY - JOUR

T1 - Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein

AU - Niederman, Richard

AU - Amrein, P. C.

AU - Hartwig, J.

PY - 1983

Y1 - 1983

N2 - Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0° and 90°. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.

AB - Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0° and 90°. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.

UR - http://www.scopus.com/inward/record.url?scp=0020965443&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0020965443&partnerID=8YFLogxK

M3 - Article

VL - 96

SP - 1400

EP - 1413

JO - Journal of Cell Biology

JF - Journal of Cell Biology

SN - 0021-9525

IS - 5

ER -