Natural F-actin VI. Degeneration of Natural F-actin and Its Protection by ATP
1973 Volume 73 Issue 4 Pages 695-703
Details
1973 Volume 73 Issue 4 Pages 695-703
When natural F-actin was incubated without the addition of ATP, its flow birefringence was easily lost. In this degeneration process, natural F-actin was conversted into three fractions designated as S2, P1, and P2. Characterization of these fractions was performed. P2 and P1 were identified as natural and denatured F-actin, respectively. S2 consisted of at least two kinds of proteins which were not identified. The apparent activation energy of the degeneration reaction was 7.3 kcal · Emole-1.
ATP was incorporated into natural F-actin with a binding constant of about 5× 10-4M-1. This suggests that natural F-actin carries weakly bound ATP, in addition to ordinarily bound ATP, which protects it from degeneration.
