Inter-monomer cross-linking affects the thermal transitions in F-actin

Chemical cross-links which covalently connected the Cys-374 and Glu-41 residues of adjacent monomers in the same strand of F-actin were used to follow the consequences of the modification for the motional and structural properties of the actin filaments. DSC measurements reported that the inter-monomer cross-links shifted the thermal transition temperature and affected strongly the cooperativity of the transition in comparison with uncross-linked F-actin. Addition of HMM to F-actin induced significant decrease of the transition temperature to lower value from 69.4 to 67. 5 °C.