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Titolo:
Interaction between PEVK-titin and actin filaments - Origin of a viscous force component in cardiac myofibrils
Autore:
Kulke, M; Fujita-Becker, S; Rostkova, E; Neagoe, C; Labeit, D; Manstein, DJ; Gautel, M; Linke, WA;
Indirizzi:
Univ Heidelberg, Inst Physiol & Pathophysiol, D-69120 Heidelberg, Germany Univ Heidelberg Heidelberg Germany D-69120 , D-69120 Heidelberg, Germany Max Planck Inst Med Res, Heidelberg, Germany Max Planck Inst Med Res Heidelberg Germany Med Res, Heidelberg, Germany Max Planck Inst Mol Physiol, D-44139 Dortmund, Germany Max Planck Inst MolPhysiol Dortmund Germany D-44139 9 Dortmund, Germany Univ Klinikum, Inst Anasthesiol & Operat Intens Med, Mannheim, Germany Univ Klinikum Mannheim Germany l & Operat Intens Med, Mannheim, Germany
Titolo Testata:
CIRCULATION RESEARCH
fascicolo: 10, volume: 89, anno: 2001,
pagine: 874 - 881
SICI:
0009-7330(20011109)89:10<874:IBPAAF>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
CAT PAPILLARY-MUSCLE; GIANT PROTEIN TITIN; I-BAND; VISCOELASTIC PROPERTIES; ELASTICITY; MOTILITY; MYOSIN; MICROTUBULES; HYPERTROPHY; INVOLVEMENT;
Keywords:
connectin; passive tension; myofibril mechanics; myocardial viscosity; actin binding protein;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Linke, WA Univ Heidelberg, Inst Physiol & Pathophysiol, Neuenheimer Feld 326, D-69120 Heidelberg, Germany Univ Heidelberg Neuenheimer Feld 326 Heidelberg Germany D-69120
Citazione:
M. Kulke et al., "Interaction between PEVK-titin and actin filaments - Origin of a viscous force component in cardiac myofibrils", CIRCUL RES, 89(10), 2001, pp. 874-881

Abstract

The giant muscle protein titin contains a unique sequence, the PEVK domain, the elastic properties of which contribute to the mechanical behavior of relaxed cardiomyocytes. Here, human N2-B-cardiac PEVK was expressed in Escherichia coli and tested-along with recombinant cardiac titin constructs containing immunoglobulin-like or fibronectin-like domains-for a possible interaction with actin filaments. In the actomyosin in vitro motility assay, only the PEVK construct inhibited actin filament sliding over myosin. The slowdown occurred in a concentration-dependent manner and was accompanied by an increase in the number of stationary actin filaments. High [Ca2+] reversed PEVK effect. PEVK concentrations greater than or equal to 10 mug/mL caused actin bundling. Actin-PEVK association was found also in actin fluorescence binding assays without myosin at physiological ionic strength. In cosedimentation assays, PEVK-titin interacted weakly with actin at 0 degreesC, but more strongly at 30 degreesC, suggesting involvement of hydrophobic interactions. To probe the interaction in a more physiological environment, nonactivated cardiac myofibrils were stretched quickly, and force was measured during the subsequent hold period. The observed force decline could be fit with a three-order exponential-decay function, which revealed an initial rapid-decay component (time constant, 4 to 5 ms) making up 30% to 50% of the whole decay amplitude. The rapid, viscous decay component, but not the slower decay components, decreased greatly and immediately on actin extraction with Ca2+-independent gelsolin fragment, both at physiological sarcomere lengths and beyond actin-myosin overlap. Steady-state passive force dropped only after longer exposure to gelsolin. We conclude that interaction betweenPEVK-titin and actin occurs in the sarcomere and may cause viscous drag during diastolic stretch of cardiac myofibrils. The interaction could also oppose shortening during contraction.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 26/11/20 alle ore 20:28:45