TAILIEUCHUNG - Báo cáo Y học: The inhibitory region of troponin-I alters the ability of F-actin to interact with different segments of myosin

Peptides corresponding to the N-terminus of skeletal myosin light chain 1 (rsMLC1 1–37) and the short loop of human cardiacb-myosin (hcM398–414) have been shown to interact with skeletal F-actin by NMR and fluorescence measurements. Skeletal tropomyosin strengthens the binding of the myosin peptides to actin but does not interact with the peptides. The binding of peptides cor-responding to the inhibitory region of cardiac troponin I (. hcTnI128–153) to F-actin to form a 1 : 1 molar complex is also strengthened in the presence of tropomyo-sin. . | Eur. J. Biochem. 269 5088-5100 2002 FEBS 2002 doi The inhibitory region of troponin-I alters the ability of F-actin to interact with different segments of myosin Valerie B. Patchell1 Clare E. Gallon2 Matthew A. Hodgkin3 Abdellatif Fattoum4 S. Victor Perry1 and Barry A. Levine1 2 1 Department of Physiology School of Medicine and 2School of Biosciences University of Birmingham Birmingham UK 3School of Biological Sciences University of Warwick Warwick UK 4CRBM CNRS INSERM U249 F-34090 Montpellier France Peptides corresponding to the N-terminus of skeletal myosin light chain 1 rsMLC1 1-37 and the short loop of human cardiac b-myosin hcM398-414 have been shown to interact with skeletal F-actin by NMR and fluorescence measurements. Skeletal tropomyosin strengthens the binding of the myosin peptides to actin but does not interact with the peptides. The binding of peptides corresponding to the inhibitory region of cardiac troponin I . hcTnI128-153 to F-actin to form a 1 1 molar complex is also strengthened in the presence of tropomyosin. In the presence of inhibitory peptide at relatively lower concentrations the myosin peptides and a troponin I peptide C-terminal to the inhibitory region rcTnI161-181 all dissociate from F-actin. Structural and fluorescence evidence indicate that the troponin I inhibitory region and the myosin peptides do not bind in an identical manner to F-actin. It is concluded that the binding of the inhibitory region of troponin I to F-actin produces a conformational change in the actin monomer with the result that interaction at different locations of F-actin is impeded. These observations are interpreted to indicate that a major conformational change occurs in actin on binding to troponin I that is fundamental to the regulatory process in muscle. The data are discussed in the context of tropomyosin s ability to stabilize the actin filament and facilitate the transmission of the conformational change to actin .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• breast cancer
• biological activities
• gastric cancer
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• bacteria
• hemoglobin
• medicine
• cell proliferation
• chemical reaction
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine