The formation of a paracrystalline structure from muscle F-actin and oligolysine.

At very low ionic strength (gamma less than 0.05) oligohomopolymers of lysine cause lateral association of muscle F-actin filaments into ordered structures which appear at low magnification in electron-micrographs as rigid needles. At higher magnification these aggregates display regular quasicrystalline patterns. The structures dissolve reversibly when the ionic strength is raised suggesting that F-actin filaments are crosslinked by oligolysine due to electrostatic forces.