Human spectrin. I. A classical light scattering study.

Human spectrin heterodimers were analyzed in solutions containing different amounts of salt employing the classical light scattering technique. 1. At 22 degrees C the radius of gyration of isolated human spectrin heterodimers in 0.1 M NaCl aqueous solution (pH 7.3) was found to be about 22 nm. 2. The radius of gyration of isolated human spectrin heterodimers was found to increase to about 40 nm as the ionic strength of the spectrin solution (pH 7.3) was reduced to about 1 mM. 3. The light scattering study indicates that the isolated human spectrin heterodimers were highly expanded and flexible molecules with a contour length exceeding about 140 nm.