title: Critical buckling length versus persistence length: what governs biofilament conformation?
abstract: We numerically study the length dependence in the bending stiffness of alpha helices, coiled coils, and a linear chain model. As the length approaches what we named the critical buckling length lc, the chain appears to become increasingly more flexible. This is due to weak nonbonded attractions that eventually lead to buckling instability and alter the chain's conformational ensemble. For alpha helices and coiled coils, lc is much less than their respective persistence lengths, so lc is the defining length scale for their conformations. These results elucidate the importance of weak nonspecific attractions that are inherent in many biofilaments in physiological conditions.
authors.affiliation: Department of Biomedical Engineering, Texas A&M University College Station, Texas 77843, USA.
authors.forename: Sirish Kaushik
authors.initials: SK
authors.lastname: Lakkaraju
authors.forename: Wonmuk
authors.initials: W
authors.lastname: Hwang
mesh_terms: D010455:Peptides / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012996:Solutions; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D014618:Vacuum
chemical_list: D010455:Peptides; D012996:Solutions; D011107:Polylysine; C019529:polyalanine; C027819:polyleucine; C011080:polyglycine