The effect of cytochalasin and glutaraldehyde on F-actin filaments containing muscle and non-muscle tropomyosin.
F-actin filaments are disrupted by the action of cytochalasin and glutaraldehyde. Muscle tropomyosin which is able to polymerize can protect F-actin against fragmentation caused by these two agents. This protective effect does not occur with nonpolymerizable, brain or carboxy-peptidase A-treated skeletal muscle tropomyosins. The protection of F-actin against the action of cytochalasin and glutaraldehyde takes place under conditions where the F-actin filaments are saturated with tropomyosin, that is, at a molar ratio of tropomyosin to actin of 1:7. It is suggested that nonpolymerizable tropomyosin lacks the protective ability because its binding to F-actin is considerably weaker than the polymerizable tropomyosin and does not saturate all of the binding sites on F-actin.
D000199:Actins / Q000378:metabolism*; D000447:Aldehydes / Q000494:pharmacology*; D000818:Animals; D003571:Cytochalasin B / Q000494:pharmacology*; D015638:Cytochalasin D; D003572:Cytochalasins / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D005976:Glutaral / Q000494:pharmacology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D009132:Muscles / Q000378:metabolism*; D011817:Rabbits; D014335:Tropomyosin / Q000378:metabolism*
D000199:Actins; D000447:Aldehydes; D003572:Cytochalasins; D046911:Macromolecular Substances; D014335:Tropomyosin; D015638:Cytochalasin D; D003571:Cytochalasin B; D005976:Glutaral