Effect of denervation on the properties of actin (according to superprecipitation data).

The superprecipitation of synthetic actomyosin, formed from intact myosin and actin extracted from rabbit white skeletal muscles 14 and 75 days after denervation has been compared with that of intact synthetic actomyosin. Superprecipitation has been characterized by two parameters. 1. The value of superprecipitation delta E determining the increase in the absorbance from minimum to maximum values; 2. the time required for the half-maximum increase (t 1/2) which is the inverse of the velocity constant. It has been shown that both the delta E and the velocity constant decrease: the delta E amounts to 75.4 +/- 7.3 per cent (p = 0.95) and 87.9 +/- 11.2 per cent (p = 0.95) after 14 and 75 days, respectively, when compared with normal; the t 1/2 increases to 41.5 +/- 13.6 per cent (p = 0.95) after 14 days and 17.5 +/- 11.9 per cent (p = 0.95) after 75 days. It is assumed that this effect is related to changes in the structure of actin.