Por favor, use este identificador para citar o enlazar este ítem: http://hdl.handle.net/10201/95163

Título: Stretching molecular springs: elasticity of titin filaments in vertebrate striated muscle
Fecha de publicación: 2000
Editorial: F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología
Cita bibliográfica: Histology and Histopathology, Vol. 15, n.º 3 (2000)
ISSN: 1699-5848
Materias relacionadas: CDU::5 - Ciencias puras y naturales::57 - Biología::576 - Biología celular y subcelular. Citología
Palabras clave: Connectin
Skeletal muscle
Cardiac muscle
Passive tension
Wormlike chain
Resumen: Titin, the giant protein of striated muscle, provides a continuous link between the Z-disk and the M-line of a sarcomere. The elastic I-band section of titin comprises two main structural elements, stretches of immunoglobulin-like domains and a unique sequence, the PEYK segment. Both elements contribute to the extensibility and passive force development of nonactivated muscle. Extensibility of the titin segments in skeletal muscle has been determined by immunof1uorescence/immunoelectron microscopy of sarcomeres stained with sequence-assigned titin antibodies. The force developed upon stretch of titin has been measured on isolated molecules or recombinant titin fragments with the help of optical tweezers and the atomic force microscope. Force has also been measured in single isolated myofibrils. The force-extension relation of titin could be readily fitted with models of biopolymer elasticity . For physiologically relevant extensions, the elasticity of the titin segments was largely explainable by an entropic-spring mechanism. The modelling explains why during stretch of titin, the Ig-domain regions (with folded modules) extend before the PEYK domain. In cardiac muscle, I-band titin is expressed in different isoforms, termed N2-A and N2-B. The N2-A isoform resembles that of skeletal muscle, whereas N2-B titin is shorter and is distinguished by cardiac-specific Ig-motifs and nonmodular sequences within the central I-band section . Examination of N2-B titin extensibility revealed that this isoform extends by recruiting three distinct elastic elements: poly-Ig regions and the PEYK domain at lower 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. However, unfolding of a very small number of Ig domains remains a possibility.
Autor/es principal/es: Linke, W. A.
URI: http://hdl.handle.net/10201/95163
Tipo de documento: info:eu-repo/semantics/article
Número páginas / Extensión: 13
Derechos: info:eu-repo/semantics/openAccess
Attribution-NonCommercial-NoDerivatives 4.0 International
Aparece en las colecciones:Vol.15, nº 3 (2000)

Ficheros en este ítem:
Fichero Descripción TamañoFormato 
Stretching molecular springs, elasticity of titin filaments in vertebrate striated muscle.pdf8,8 MBAdobe PDFVista previa

Este ítem está sujeto a una licencia Creative Commons Licencia Creative Commons Creative Commons