Dynamic light-scattering study of muscle F-actin. II

Satoru Fujime, Michiho Takasaki-Ohsita, Shin'ichi Ishiwata

    Research output: Contribution to journalArticle

    2 Citations (Scopus)

    Abstract

    By dynamic light scattering, the intensity autocorrelation unction, G2(τ) = B[1+β|g1(τ)|2],was obtained over the scattering angles (θ) from 30 to 130° in steps of 10° for semidilute solutions of muscle F-actin and of F-actin complexed with heavy meromyosin in the absence of ATP (acto-HMM), where B is the baseline and β a constant. The main findings were: (1) A 0.5 mg/ml F-actin solution gave nonreproducible spectra at θ ≦ 40° but quite reproducible spectra at θ ≧ 50°, with β = 0.9-0.8 at all θ values. Nonreproducibility of spectra at low θ values was concluded to be due to restricted motions of very long filaments confined in cages or zig- zag tubing formed by a major fraction of filaments, where the very long filaments were those at a distant tail of an exponential length distribution and the major fraction of filaments were those with lengths around Ln-2Ln, Ln being the number-average length. Spectral widths were compared with theoretical ones for rigid rods averaged over the length distribution with Ln = 900 nm, and were suggested to be largely contributed at high θ values from bending motions of filaments. (2) Acto-HMM solutions at 0.5 mg/ml F- actin and at weight ratios of HMM to F-actin of 0.5-2 gave spectra which, with respect to θ, behaved very similarly to those of F-actin alone. The spectral widths, however, drastically decreased with the weight ratio up to unity and stayed virtually constant above unity. In contrast to a previous study (F.D. Carlson and A.B. Fraser, J. Mol. Biol. 89 (1974) 273), β values of acto-HMM were as large as those of F- actin alone. Acto-HMM was concluded to travel a distance far greater than 1/K with a mobility smaller than that of F-actin, where K = ( 4iπ/λ) sin(θ/2), λ being the wavelength of light in the medium. These results suggest that acto-HMM gels are very soft even though they did not pour from an inverted cell. Based on several intuitive models which give a mutual relationship between the β value and modes of motions of scatterers, we discuss the restricted motions responsible for nonreproducibility of spectra at low angles and large β values of acto-HMM gels at all θ values and weight ratios so far studied.

    Original languageEnglish
    Pages (from-to)211-224
    Number of pages14
    JournalBiophysical Chemistry
    Volume27
    Issue number3
    DOIs
    Publication statusPublished - 1987

    Fingerprint

    pioglitazone
    Dynamic light scattering
    muscles
    Muscle
    Actins
    filaments
    light scattering
    Muscles
    unity
    gels
    Weights and Measures
    adenosine triphosphate
    scattering
    Gels
    travel
    autocorrelation
    Myosin Subfragments
    rods
    Dynamic Light Scattering
    Tubing

    Keywords

    • Dynamic light scattering
    • F-Actin
    • Filament flexibility
    • Heavy meromyosin
    • Semidilute solution

    ASJC Scopus subject areas

    • Biochemistry
    • Biophysics
    • Physical and Theoretical Chemistry

    Cite this

    Dynamic light-scattering study of muscle F-actin. II. / Fujime, Satoru; Takasaki-Ohsita, Michiho; Ishiwata, Shin'ichi.

    In: Biophysical Chemistry, Vol. 27, No. 3, 1987, p. 211-224.

    Research output: Contribution to journalArticle

    Fujime, S, Takasaki-Ohsita, M & Ishiwata, S 1987, 'Dynamic light-scattering study of muscle F-actin. II', Biophysical Chemistry, vol. 27, no. 3, pp. 211-224. https://doi.org/10.1016/0301-4622(87)80060-1
    Fujime, Satoru ; Takasaki-Ohsita, Michiho ; Ishiwata, Shin'ichi. / Dynamic light-scattering study of muscle F-actin. II. In: Biophysical Chemistry. 1987 ; Vol. 27, No. 3. pp. 211-224.
    @article{951c8860739944999a32710c7b3dfd9d,
    title = "Dynamic light-scattering study of muscle F-actin. II",
    abstract = "By dynamic light scattering, the intensity autocorrelation unction, G2(τ) = B[1+β|g1(τ)|2],was obtained over the scattering angles (θ) from 30 to 130° in steps of 10° for semidilute solutions of muscle F-actin and of F-actin complexed with heavy meromyosin in the absence of ATP (acto-HMM), where B is the baseline and β a constant. The main findings were: (1) A 0.5 mg/ml F-actin solution gave nonreproducible spectra at θ ≦ 40° but quite reproducible spectra at θ ≧ 50°, with β = 0.9-0.8 at all θ values. Nonreproducibility of spectra at low θ values was concluded to be due to restricted motions of very long filaments confined in cages or zig- zag tubing formed by a major fraction of filaments, where the very long filaments were those at a distant tail of an exponential length distribution and the major fraction of filaments were those with lengths around Ln-2Ln, Ln being the number-average length. Spectral widths were compared with theoretical ones for rigid rods averaged over the length distribution with Ln = 900 nm, and were suggested to be largely contributed at high θ values from bending motions of filaments. (2) Acto-HMM solutions at 0.5 mg/ml F- actin and at weight ratios of HMM to F-actin of 0.5-2 gave spectra which, with respect to θ, behaved very similarly to those of F-actin alone. The spectral widths, however, drastically decreased with the weight ratio up to unity and stayed virtually constant above unity. In contrast to a previous study (F.D. Carlson and A.B. Fraser, J. Mol. Biol. 89 (1974) 273), β values of acto-HMM were as large as those of F- actin alone. Acto-HMM was concluded to travel a distance far greater than 1/K with a mobility smaller than that of F-actin, where K = ( 4iπ/λ) sin(θ/2), λ being the wavelength of light in the medium. These results suggest that acto-HMM gels are very soft even though they did not pour from an inverted cell. Based on several intuitive models which give a mutual relationship between the β value and modes of motions of scatterers, we discuss the restricted motions responsible for nonreproducibility of spectra at low angles and large β values of acto-HMM gels at all θ values and weight ratios so far studied.",
    keywords = "Dynamic light scattering, F-Actin, Filament flexibility, Heavy meromyosin, Semidilute solution",
    author = "Satoru Fujime and Michiho Takasaki-Ohsita and Shin'ichi Ishiwata",
    year = "1987",
    doi = "10.1016/0301-4622(87)80060-1",
    language = "English",
    volume = "27",
    pages = "211--224",
    journal = "Biophysical Chemistry",
    issn = "0301-4622",
    publisher = "Elsevier",
    number = "3",

    }

    TY - JOUR

    T1 - Dynamic light-scattering study of muscle F-actin. II

    AU - Fujime, Satoru

    AU - Takasaki-Ohsita, Michiho

    AU - Ishiwata, Shin'ichi

    PY - 1987

    Y1 - 1987

    N2 - By dynamic light scattering, the intensity autocorrelation unction, G2(τ) = B[1+β|g1(τ)|2],was obtained over the scattering angles (θ) from 30 to 130° in steps of 10° for semidilute solutions of muscle F-actin and of F-actin complexed with heavy meromyosin in the absence of ATP (acto-HMM), where B is the baseline and β a constant. The main findings were: (1) A 0.5 mg/ml F-actin solution gave nonreproducible spectra at θ ≦ 40° but quite reproducible spectra at θ ≧ 50°, with β = 0.9-0.8 at all θ values. Nonreproducibility of spectra at low θ values was concluded to be due to restricted motions of very long filaments confined in cages or zig- zag tubing formed by a major fraction of filaments, where the very long filaments were those at a distant tail of an exponential length distribution and the major fraction of filaments were those with lengths around Ln-2Ln, Ln being the number-average length. Spectral widths were compared with theoretical ones for rigid rods averaged over the length distribution with Ln = 900 nm, and were suggested to be largely contributed at high θ values from bending motions of filaments. (2) Acto-HMM solutions at 0.5 mg/ml F- actin and at weight ratios of HMM to F-actin of 0.5-2 gave spectra which, with respect to θ, behaved very similarly to those of F-actin alone. The spectral widths, however, drastically decreased with the weight ratio up to unity and stayed virtually constant above unity. In contrast to a previous study (F.D. Carlson and A.B. Fraser, J. Mol. Biol. 89 (1974) 273), β values of acto-HMM were as large as those of F- actin alone. Acto-HMM was concluded to travel a distance far greater than 1/K with a mobility smaller than that of F-actin, where K = ( 4iπ/λ) sin(θ/2), λ being the wavelength of light in the medium. These results suggest that acto-HMM gels are very soft even though they did not pour from an inverted cell. Based on several intuitive models which give a mutual relationship between the β value and modes of motions of scatterers, we discuss the restricted motions responsible for nonreproducibility of spectra at low angles and large β values of acto-HMM gels at all θ values and weight ratios so far studied.

    AB - By dynamic light scattering, the intensity autocorrelation unction, G2(τ) = B[1+β|g1(τ)|2],was obtained over the scattering angles (θ) from 30 to 130° in steps of 10° for semidilute solutions of muscle F-actin and of F-actin complexed with heavy meromyosin in the absence of ATP (acto-HMM), where B is the baseline and β a constant. The main findings were: (1) A 0.5 mg/ml F-actin solution gave nonreproducible spectra at θ ≦ 40° but quite reproducible spectra at θ ≧ 50°, with β = 0.9-0.8 at all θ values. Nonreproducibility of spectra at low θ values was concluded to be due to restricted motions of very long filaments confined in cages or zig- zag tubing formed by a major fraction of filaments, where the very long filaments were those at a distant tail of an exponential length distribution and the major fraction of filaments were those with lengths around Ln-2Ln, Ln being the number-average length. Spectral widths were compared with theoretical ones for rigid rods averaged over the length distribution with Ln = 900 nm, and were suggested to be largely contributed at high θ values from bending motions of filaments. (2) Acto-HMM solutions at 0.5 mg/ml F- actin and at weight ratios of HMM to F-actin of 0.5-2 gave spectra which, with respect to θ, behaved very similarly to those of F-actin alone. The spectral widths, however, drastically decreased with the weight ratio up to unity and stayed virtually constant above unity. In contrast to a previous study (F.D. Carlson and A.B. Fraser, J. Mol. Biol. 89 (1974) 273), β values of acto-HMM were as large as those of F- actin alone. Acto-HMM was concluded to travel a distance far greater than 1/K with a mobility smaller than that of F-actin, where K = ( 4iπ/λ) sin(θ/2), λ being the wavelength of light in the medium. These results suggest that acto-HMM gels are very soft even though they did not pour from an inverted cell. Based on several intuitive models which give a mutual relationship between the β value and modes of motions of scatterers, we discuss the restricted motions responsible for nonreproducibility of spectra at low angles and large β values of acto-HMM gels at all θ values and weight ratios so far studied.

    KW - Dynamic light scattering

    KW - F-Actin

    KW - Filament flexibility

    KW - Heavy meromyosin

    KW - Semidilute solution

    UR - http://www.scopus.com/inward/record.url?scp=0023411102&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0023411102&partnerID=8YFLogxK

    U2 - 10.1016/0301-4622(87)80060-1

    DO - 10.1016/0301-4622(87)80060-1

    M3 - Article

    C2 - 3663844

    AN - SCOPUS:0023411102

    VL - 27

    SP - 211

    EP - 224

    JO - Biophysical Chemistry

    JF - Biophysical Chemistry

    SN - 0301-4622

    IS - 3

    ER -