Interaction of myosin subfragment 1 with F-actin studied by differential scanning calorimetry.
The thermal unfolding of the myosin subfragment 1 (S1) and of filamentous actin (F-actin) in their strong complex obtained in the presence of ADP was studied by differential scanning calorimetry (DSC). It is shown that in the acto-S1 complexes S1 and F-actin melt separately, and thermal transitions of each protein can be easily followed. Interaction of S1 with F-actin significantly increases S1 thermal stability and also affects the thermal stability of F-actin. Although S1 unfolds at much lower temperature than F-actin, the molecules of S1 remain bound to F-actin even after full denaturation. Under these conditions S1 may induce cross-linking between actin filaments. It is concluded that DSC studies on the acto-S1 complexes offer a new and promising approach to investigate the structural changes which occur in the myosin head and in F-actin due to their interaction.
Nikolaeva
O P
OP
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
Orlov
V N
VN
Dedova
I V
IV
Drachev
V A
VA
Levitsky
D I
DI
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002152:Calorimetry, Differential Scanning; D015879:Myosin Subfragments / Q000378:metabolism*; D011487:Protein Conformation; D011817:Rabbits
D000199:Actins; D015879:Myosin Subfragments