Fluorescence measurements detect changes in scallop myosin regulatory domain

A. Málnási-Csizmadia, György Hegyi, F. Tölgyesi, Andrew G. Szent-Györgyi, L. Nyitray

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Ca2+-induced conformational changes of scallop myosin regulatory domain (RD) were studied using intrinsic fluorescence. Both tile intensity and anisotropy of tryptophan fluorescence decreased significantly upon removal of Ca2+. By making a mutant RD we found that the Ca2+-induced fluorescence change is due mainly to Trp21 of the essential light chain which is located at the unusual Ca2+-binding EF-hand motif of the first domain. This result suggests that Trp21 is in a less hydrophobic and more flexible environment in the Ca2+-free state, supporting a model for regulation based on the 2 Å resolution structure of scallop RD with bound Ca2+ [Houdusse A. and Cohen C. (1996) Structure 4, 21-32]. Binding of the fluorescent probe, 8- anilinonaphthalene-1-sulphonate (ANS) to the RD senses the dissociation of the regulatory light chain (RLC) in the presence of EDTA, by energy transfer from a tryptophan cluster (Trp818, 824, 826, 827) on the heavy chain (HC). We identified a hydrophobic pentapeptide (Leu836-Ala840) at the head-rod junction which is required for the effective energy transfer and conceivably is part of the ANS-binding site. Extension of the HC component of RD towards the rod region results in a larger ANS response, presumably indicating changes in HC-RLC interactions, which might be crucial for the regulatory function of scallop myosin.

Original languageEnglish
Pages (from-to)452-458
Number of pages7
JournalEuropean Journal of Biochemistry
Volume261
Issue number2
DOIs
Publication statusPublished - Apr 15 1999

Fingerprint

N-phenyl-1-naphthylamine
Pectinidae
Myosins
Fluorescence
Energy Transfer
Light
Tryptophan
Energy transfer
EF Hand Motifs
Fluorescence Polarization
Tile
Fluorescent Dyes
Edetic Acid
Anisotropy
Binding Sites
Head

Keywords

  • Ca binding
  • Fluorescence
  • Myosin light chains
  • Tryptophan

ASJC Scopus subject areas

  • Biochemistry

Cite this

Fluorescence measurements detect changes in scallop myosin regulatory domain. / Málnási-Csizmadia, A.; Hegyi, György; Tölgyesi, F.; Szent-Györgyi, Andrew G.; Nyitray, L.

In: European Journal of Biochemistry, Vol. 261, No. 2, 15.04.1999, p. 452-458.

Research output: Contribution to journalArticle

@article{2c212b92a82a43ae92f6ae2ce07f3544,
title = "Fluorescence measurements detect changes in scallop myosin regulatory domain",
abstract = "Ca2+-induced conformational changes of scallop myosin regulatory domain (RD) were studied using intrinsic fluorescence. Both tile intensity and anisotropy of tryptophan fluorescence decreased significantly upon removal of Ca2+. By making a mutant RD we found that the Ca2+-induced fluorescence change is due mainly to Trp21 of the essential light chain which is located at the unusual Ca2+-binding EF-hand motif of the first domain. This result suggests that Trp21 is in a less hydrophobic and more flexible environment in the Ca2+-free state, supporting a model for regulation based on the 2 {\AA} resolution structure of scallop RD with bound Ca2+ [Houdusse A. and Cohen C. (1996) Structure 4, 21-32]. Binding of the fluorescent probe, 8- anilinonaphthalene-1-sulphonate (ANS) to the RD senses the dissociation of the regulatory light chain (RLC) in the presence of EDTA, by energy transfer from a tryptophan cluster (Trp818, 824, 826, 827) on the heavy chain (HC). We identified a hydrophobic pentapeptide (Leu836-Ala840) at the head-rod junction which is required for the effective energy transfer and conceivably is part of the ANS-binding site. Extension of the HC component of RD towards the rod region results in a larger ANS response, presumably indicating changes in HC-RLC interactions, which might be crucial for the regulatory function of scallop myosin.",
keywords = "Ca binding, Fluorescence, Myosin light chains, Tryptophan",
author = "A. M{\'a}ln{\'a}si-Csizmadia and Gy{\"o}rgy Hegyi and F. T{\"o}lgyesi and Szent-Gy{\"o}rgyi, {Andrew G.} and L. Nyitray",
year = "1999",
month = "4",
day = "15",
doi = "10.1046/j.1432-1327.1999.00290.x",
language = "English",
volume = "261",
pages = "452--458",
journal = "FEBS Journal",
issn = "1742-464X",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Fluorescence measurements detect changes in scallop myosin regulatory domain

AU - Málnási-Csizmadia, A.

AU - Hegyi, György

AU - Tölgyesi, F.

AU - Szent-Györgyi, Andrew G.

AU - Nyitray, L.

PY - 1999/4/15

Y1 - 1999/4/15

N2 - Ca2+-induced conformational changes of scallop myosin regulatory domain (RD) were studied using intrinsic fluorescence. Both tile intensity and anisotropy of tryptophan fluorescence decreased significantly upon removal of Ca2+. By making a mutant RD we found that the Ca2+-induced fluorescence change is due mainly to Trp21 of the essential light chain which is located at the unusual Ca2+-binding EF-hand motif of the first domain. This result suggests that Trp21 is in a less hydrophobic and more flexible environment in the Ca2+-free state, supporting a model for regulation based on the 2 Å resolution structure of scallop RD with bound Ca2+ [Houdusse A. and Cohen C. (1996) Structure 4, 21-32]. Binding of the fluorescent probe, 8- anilinonaphthalene-1-sulphonate (ANS) to the RD senses the dissociation of the regulatory light chain (RLC) in the presence of EDTA, by energy transfer from a tryptophan cluster (Trp818, 824, 826, 827) on the heavy chain (HC). We identified a hydrophobic pentapeptide (Leu836-Ala840) at the head-rod junction which is required for the effective energy transfer and conceivably is part of the ANS-binding site. Extension of the HC component of RD towards the rod region results in a larger ANS response, presumably indicating changes in HC-RLC interactions, which might be crucial for the regulatory function of scallop myosin.

AB - Ca2+-induced conformational changes of scallop myosin regulatory domain (RD) were studied using intrinsic fluorescence. Both tile intensity and anisotropy of tryptophan fluorescence decreased significantly upon removal of Ca2+. By making a mutant RD we found that the Ca2+-induced fluorescence change is due mainly to Trp21 of the essential light chain which is located at the unusual Ca2+-binding EF-hand motif of the first domain. This result suggests that Trp21 is in a less hydrophobic and more flexible environment in the Ca2+-free state, supporting a model for regulation based on the 2 Å resolution structure of scallop RD with bound Ca2+ [Houdusse A. and Cohen C. (1996) Structure 4, 21-32]. Binding of the fluorescent probe, 8- anilinonaphthalene-1-sulphonate (ANS) to the RD senses the dissociation of the regulatory light chain (RLC) in the presence of EDTA, by energy transfer from a tryptophan cluster (Trp818, 824, 826, 827) on the heavy chain (HC). We identified a hydrophobic pentapeptide (Leu836-Ala840) at the head-rod junction which is required for the effective energy transfer and conceivably is part of the ANS-binding site. Extension of the HC component of RD towards the rod region results in a larger ANS response, presumably indicating changes in HC-RLC interactions, which might be crucial for the regulatory function of scallop myosin.

KW - Ca binding

KW - Fluorescence

KW - Myosin light chains

KW - Tryptophan

UR - http://www.scopus.com/inward/record.url?scp=0033561359&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033561359&partnerID=8YFLogxK

U2 - 10.1046/j.1432-1327.1999.00290.x

DO - 10.1046/j.1432-1327.1999.00290.x

M3 - Article

C2 - 10215856

AN - SCOPUS:0033561359

VL - 261

SP - 452

EP - 458

JO - FEBS Journal

JF - FEBS Journal

SN - 1742-464X

IS - 2

ER -