title: Unique elastic properties of the spectrin tetramer as revealed by multiscale coarse-grained modeling.
abstract: The force-extension profile of tetrameric spectrin is determined by using multiscale computer simulation. Fluctuation results of atomistic simulations of double spectrin repeat units (DSRU) are used to systematically build a coarse-grained (CG) model for the tetrameric form of spectrin. It is found that the spectrin tetramer can be modeled as a soft polymer with a unique flat force-extension profile over the range of biologically important lengths. It is also concluded that in the cytoskeletal network of the red blood cell the tetramer is in an "overcompressed" state. These findings are in contrast to the commonly used models of spectrin tetramer elasticity, namely the "entropic spring" polymer models. From these results, it is concluded that stable intact helical linker regions are needed to maintain the soft elasticity of the spectrin tetramer.
authors.affiliation: Center for Biophysical Modeling and Simulation and Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT 84112-0850, USA.
authors.forename: Dina T
authors.initials: DT
authors.lastname: Mirijanian
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Voth
mesh_terms: D003198:Computer Simulation; D004548:Elasticity; D004907:Erythrocyte Deformability / Q000502:physiology; D004912:Erythrocytes / Q000737:chemistry / Q000502:physiology; D006801:Humans; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D011108:Polymers / Q000737:chemistry; D017510:Protein Folding; D020449:Repetitive Sequences, Amino Acid; D013049:Spectrin / Q000737:chemistry* / Q000502:physiology; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D011108:Polymers; D013049:Spectrin