The binding of cytochalasin D to monomeric actin.
The binding of cytochalasin D to monomeric actin has been measured directly. In the presence of 200 microM Ca2+, actin binds cytochalasin D in a 1:1 molar ratio with a KD of 18 microM. After incubation with 250 microM Mg2+ for 10 minutes, actin binds cytochalasin D with a KD of 2.6 microM but with one mole of cytochalasin D per 2 moles of actin. This suggests that cytochalasin D induces dimerization of Mg2+-induced actin monomers.
D000199:Actins / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D015638:Cytochalasin D; D003572:Cytochalasins / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D011487:Protein Conformation / Q000187:drug effects; D011817:Rabbits
C022920:ATP-G-actin; D000199:Actins; D003572:Cytochalasins; D015638:Cytochalasin D; D000255:Adenosine Triphosphate; D008274:Magnesium; D002118:Calcium