||Wingreen NS, Huang KC. Physics of Intracellular Organization in Bacteria. Annu Rev Microbiol. 2015 Oct 15 69: 361-79. doi: 10.1146/annurev-micro-091014-104313. p.366 5th paragraphPubMed ID26488278
||Kojima H, Ishijima A, Yanagida T. 1994. Direct measurement of stiffness of single actin filaments with and without tropomyosin by in vitro nanomanipulation. PNAS 91: 12962–66PubMed ID7809155
||Primary source abstract:"Here, [investigators] directly measure the stiffness of single actin filaments with and without tropomyosin, using a recently developed technique for nanomanipulation of single actin filaments with microneedles."
||p.366 3rd paragraph:"To gain intuition about how the physical properties of a filament affect its bending, consider a protein filament as a cylinder with radius r and preferred radius of curvature R that bends uniformly along its length. The bending modulus is set by Young's modulus of the protein, which for actin is ∼2 GPa (primary source)."