Mechanical strength of sarcomere structures of skeletal myofibrils studied by submicromanipulation.

Abstract

The mechanical strength of sarcomere structures of skeletal muscle was studied by rupturing single myofibrils of rabbit psoas muscle by submicromanipulation techniques. Microbeads coated with alpha-actinin were attached to the surface of myofibrils immobilized to coverslip. By use of either optical tweezers or atomic force microscope, the attached beads were captured and detached from the myofibrils. During the detachment of the beads, the actin filaments bound specifically to the beads were peeled off from the bulk structures of myofibrils, thus rupturing the peripheral components of the myofibrils bound to the actin filaments. By analyzing the ruptures thus produced in various myofibril preparations, it was found that the sarcomere structure of myofibrils is maintained by numerous molecular components having the mechanical strength sufficient to sustain the contractile force produced by the actomyosin system. The present techniques could be applied to study the mechanical strength of cellular organelles containing actin filaments as their component.

• Authors: Taisuke Kayamori, Norihito Miyake, Nao Akiyama, Momoko Aimi, Jun'ichi Wakayama, Yuki Kunioka, Takenori Yamada
• Journal: Cell structure and function (Cell Struct Funct) Vol. 31 Issue 2 Pg. 135-43 ( 2006) ISSN: 1347-3700 [Electronic] Japan
• PMID: 17110784 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Actinin

Topics

• Actin Cytoskeleton (physiology, ultrastructure)
• Actinin
• Animals
• Biomechanical Phenomena
• Electrophoresis, Polyacrylamide Gel
• Micromanipulation (methods)
• Microscopy, Atomic Force
• Microspheres
• Muscle Contraction (physiology)
• Myofibrils (physiology, ultrastructure)
• Psoas Muscles (physiology, ultrastructure)
• Rabbits
• Sarcomeres (physiology, ultrastructure)