Insights into Skeletal Muscle Contraction Modeling: Fibre Diffraction & Energy Transduction
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Explore fibre diffraction's role in modeling skeletal muscle, alongside insights on myosin's allosteric behavior and chemomechanical coupling for energy transduction. Understand the actin dynamics and mechanics involved.
Insights into Skeletal Muscle Contraction Modeling: Fibre Diffraction & Energy Transduction
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Presentation Transcript
NTP metabolism and transduction CS35: Models for skeletal muscle contraction Biochemistry 655 6 April 2011
Goals • Understand the role of fibre diffraction in modeling skeletal muscle • The equatorial pattern ([1,0] and [1,1] reflections) • The meridional pattern (axial repeats) • Symmetry mismatches • The time-dependence of events involved in contraction • Assembling actomyosin from crystal structures • Multiple states of myosin • Problems associated with the fitting of actin crystal structures (Page, Schutt) • The actin helix-ribbon transition • Possible descent of myosin and actin from class I, II aaRS
Hinge-bending Shear Rigid-bodies Actin dynamics
Motif 1 is “domain swapped” in HSP70 and SerRS Motif 2 superimposes on the HSP70 ATP-binding motif Strand-loop-helix that fixes thea-NH2 group in Class II aaRS also in HSP70 Class I & II tertiary scaffolds can be coded as SASORFs!!Carter & Duax, Molecular Cell, (2002) 10:705-708 Myosin? Actin?
NTP metabolism and transduction CS36: Energy transduction revisited: a retrospective and summary Biochemistry 655 18 November 2009
Goals • Discuss the allosteric behavior of myosin (Shriver & Sykes). • Multiple energy wells • Different ligand affinities • Recite the abstract from Marsten, et al. • Understand the meaning of all terms! • Describe the effect of AMPPNP • Is it really non-hydrolyzable? • If so, how to explain its effects on glycerol extracted muscle? • Walking through the cross-bridge cycle in reverse. • Understand why the “series elastic component” is necessary. • Terrill Hill’s model • Efficiency of energy conversion • The actin helix-ribbon transition (Schutt)
ATP ADP + Pi Myosin is an allosteric enzyme