Abstract
Skeletal-muscle titin contains in its I-band section two main elastic elements, stretches of Ig-like domains and the PEVK segment. Both elements contribute to the extensibility and passive force development of relaxed skeletal muscle fibers during stretch. To explore the nature of elasticity of the segments, their force-extension relation was determined with immunofluorescence and immunoelectron microscopy, combined with isolated myofibril mechanics. The results were then fitted with recent models of biopolymer elasticity. Whereas an entropic-spring mechanism may account for the elasticity of the Ig-domain segments, PEVK-titin elasticity appears to have both entropic and enthalpic origins. The modeling explains why the two elements extend sequentially upon stretch: elongation of the Ig-domain regions (with folded modules) is followed by unraveling of the PEVK domain.
I-band titin in cardiac muscle is expressed in two main isoforms, N2-A and N2-B. The N2-A isoform is similar to that found in skeletal muscle, whereas the N2-B titin is distinguished by cardiac-specific Ig-motifs and nonmodular sequences within the central I-band section. By examining the extensibility of N2-B titin, it was found that this isoform extends by recruiting three distinct elastic elements: poly-Ig regions and the PEVK domain at low to modest stretch, and in addition, a unique 572-residue sequence insertion at higher physiological stretch. Extension of all three elements allows cardiac titin to stretch fully reversibly at physiological sarcomere lengths, without the need to unfold individual Ig domains.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Allen DG, Kentish JC. The cellular basis of the length-tension relation in cardiac muscle. J Mol Cell Cardiol 1985;17:821–40.
Bartoo ML, Popov VI, Fearn LA, Pollack GH. Active tension generation in isolated skeletal myofibrils. J Muscle Res Cell Motil 1993;14:498–510.
Bartoo ML, Linke WA, Pollack GH. Basis of passive tension and stiffness in isolated rabbit myofibrils. Am J Physiol 1997;273:C266–76.
Bustamante C, Marko JF, Siggia ED, Smith S. Entropic elasticity of 1-phage DNA. Science 1994;265:1599–1600.
Erickson HP. Reversible unfolding of fibronectin type III and immunoglobulin domains provides the structural basis for stretch and elasticity of titin and fibronectin. Proc Natl Acad SciUSA1994;91:10114–8.
Fürst DO, Osborn M, Nave R, Weber K. The organization of titin filaments in the half-sarcomere revealed by monoclonal antibodies in immunoelectron microscopy: a map often nonrepetitive epitopes starting at the Z-line extends close to the M-line. J Cell Biol 1988;106:1563–72.
Gautel M, Goulding D. A molecular map of titin/connectin elasticity reveals two different mechanisms acting in series. FEBS Lett 1996;385:11–4.
Gautel M, Lehtonen E, Pietruschka F. Assembly of the cardiac I-band region of titin/connectin: expression of the cardiac-specific regions and their relation to the elastic segments. J Muscle Res Cell Motil 1996;17:449–61.
Granzier H, Kellermayer M, Helmes M, Trombitas K. Titin elasticity and mechanism of passive force development in rat cardiac myocytes probed by thin-filament extraction. Biophys J 1997;73:2043–53.
Gregorio CC, Granzier H, Sorimachi H, Labeit S. Muscle assembly: a titanic achievement? Curr Opin Cell Biol 1999;11:18–25.
Gutierrez G, van Heerden A, Wang K. Interactions and conformational studies of PEVK segment of human fetal skeletal muscle titin. Biophys J 1998;2(2):A349.
Higuchi H, Nakauchi Y, Maruyama K, Fujime S. Characterization of β-connectin (titin 2) from striated muscle by dynamic light scattering. Biophys J 1993;65:1906–15.
Kellermayer MS, Granzier HL. Calcium-dependent inhibition of in vitro thin-filament motility by native titin. FEBS Lett 1996;380:281–6.
Kellermayer MSZ, Smith SB, Granzier HL, Bustamante C. Folding-unfolding transitions in single titin molecules characterized with laser tweezers. Science 1997;276:1112–6.
Labeit S, Kolmerer B. Titins, giant proteins in charge of muscle ultrastructure and elasticity. Science 1995;270:293–6.
Labeit S, Kolmerer B, Linke WA. The giant protein titin. Emerging roles in physiology and pathophysiology. Circ Res 1997;80:290–4.
Linke WA, Ivemeyer M, Mündel P, Stockmeier MR, Kolmerer B. Nature of PEVK-titin elasticity in skeletal muscle. Proc Natl Acad Sci USA 1998a;95:8052–7.
Linke WA, Ivemeyer M, Olivieri N, Kolmerer B, Riiegg JC, Labeit S. Towards a molecular understanding of the elasticity of titin. J Mol Biol 1996,261:62–71.
Linke WA, Popov VI, Pollack GH. Passive and active tension in single cardiac myofibrils. Biophys J 1994;67:782–92.
Linke WA, Rudy DE, Centner T, Gautel M, Witt C, Labeit S, Gregorio CC. I-band titin in cardiac muscle is a three-element molecular spring and is critical for maintaining thin filament structure. J. Cell Biol 1999;146:631–44.
Linke WA, Stockmeier MR, Ivemeyer M, Hosser H, Mündel P. Characterizing titin’s I-band Ig domain region as an entropie spring. J Cell Sci 1998b;111:1567–74.
Marko JF, Siggia ED. Stretching DNA. Macromolecules 1995;28:8759–70.
Maruyama K. Connectin, an elastic protein of striated muscle. Biophys Chem 1994,50:73–85.
Maruyama K. Connectin/titin, giant elastic protein of muscle. FASEB J 1997;11:341–5.
Mündel P, Gilbert P, Kriz W. Podocytes in glomerulus of rat kidney express a characteristic 44 kD protein. J Histochem Cytochem 1991;39:1047–56.
Odijk T. Stiff chains and filaments under tension. Macromolecules 1995;28:7016–8.
Politou AS, Thomas DJ, Pastore A. The folding and stability of titin immunoglobulin-like modules, with implications for the mechanism of elasticity. Biophys J 1995;69:2601–10.
Rief M, Gautel M, Oesterhelt F, Fernandez JM, Gaub HE. Reversible unfolding of individual titin immunoglobulin domains by AFM. Science 1997;276:1109–12.
Smith SB, Cui Y, Bustamante C. Overstretching B-DNA: the elastic response of individual double-stranded and single-stranded DNA molecules. Science 1996,271:795–9.
Tokuyasu KT. Use of poly(vinylpyrrolidone) and poly(vinyl alcohol) for cryoultramicrotomy. Histochem J 1989;21:163–71.
Trinick J. Cytoskeleton: Titin as a scaffold and spring. Curr Biol 1996;6:258–60.
Trombitás K, Greaser M, Labeit S, Jin J-P, Kellermayer M, Helmes M, Granzier H. Titin extensibility in situ: Entropic elasticity of permanently folded and permanently unfolded molecular segments. J Cell Biol 1998;140:853–9.
Trombitás K, Jin J-P, Granzier H. The mechanically active domain of titin in cardiac muscle. Circ Res 1995,77:856–61.
Tskhovrebova L, Trinick J. Direct visualization of extensibility in isolated titin molecules. J Mol Biol 1997,265:100–6.
Tskhovrebova L, Trinick J, Sleep JA, Simmons RM. Elasticity and unfolding of single molecules of the giant muscle protein titin. Nature 1997;387:308–12.
Wang K. Titin/connectin and nebulin: giant protein rulers of muscle structure and function. Adv Biophys 1996;33:123–34.
Wang MD, Yin H, Landick R, Gelles J, Block SM. Stretching DNA with optical tweezers. Biophys J 1997;72:1335–46.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2000 Springer Science+Business Media New York
About this chapter
Cite this chapter
Linke, W.A. (2000). Titin Elasticity in the Context of the Sarcomere: Force and Extensibility Measurements on Single Myofibrils. In: Granzier, H.L., Pollack, G.H. (eds) Elastic Filaments of the Cell. Advances in Experimental Medicine and Biology, vol 481. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-4267-4_11
Download citation
DOI: https://doi.org/10.1007/978-1-4615-4267-4_11
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-6916-5
Online ISBN: 978-1-4615-4267-4
eBook Packages: Springer Book Archive