The Effect of Toxofilin on the Structure and Dynamics of Monomeric Actin

FEBS Lett. 2015 Sep 5. pii: S0014-5793(15)00808-X. doi: 10.1016/j.febslet.2015.08.038. [Epub ahead of print]

 

Czimbalek L¹, Kollár V¹, Kardos R¹, Lőrinczy D¹, Nyitrai M², Hild G³.

 

The effects of toxofilin (an actin binding protein of Toxoplasma gondii) on G-actin was studied with spectroscopy techniques. Fluorescence anisotropy measurements proved that G-actin and toxofilin interact with 2:1 stoichiometry. The affinity of toxofilin to actin was also determined with a fluorescence anisotropy assay. Fluorescence quenching experiments showed that the accessibility of the actin bound ε-ATP decreased in the presence of toxofilin. The results can be explained by the shift of the nucleotide binding cleft into a closed conformational state. Differential scanning calorimetry measurements revealed that actin monomers become thermodynamically more stable due to the binding of toxofilin.
Copyright © 2015. Published by Elsevier B.V.

PMID:

26348398

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