The Journal of Biological Physics and Chemistry

Glutamic acid-based hinges in myosin II

G. Managadze,⁺ B. Vishnepolsky⁺ and M. Pirtskhalava*

Institute of Molecular Biology and Biological Physics, 12 Gotua St, 0160 Tbilisi, Georgia

Short sections of the N-terminal half of some striated and smooth muscle myosin rods have been found where clusters of Asp and Glu destabilize helical structure when ionized. Distributions of Asp, Glu, Lys, Arg, and His in two-stranded coiled-coil sequences have been studied with the aim of evaluating the role of charged amino acids, and it is shown that short fragments, rich with acidic amino acids occur only in the myosin S2 parts. The role of Glu in hinge formation was investigated using the conformational capability of the model peptide (Glu)₁₀ in the charged and uncharged states and of the two-stranded coiled-coils, where the Glu in both the charged and uncharged states is in the a or d position of the heptad. The results confirm the proposition that the S2 glutamines are the basis of the unidirectional conformational transition as a result of charging or discharging their side chains

Keywords: coiled-coil, distributions, myosin, uncharged and charged glutamic acid