[The study of actin in denervated skeletal muscles by microcalorimetry].

Method of scanning calorimetry of intact and denervated F-actin shows a change in thermostability of protein after denervation.

[Circular dichroism of actin from denervated skeletal muscles].

Method of circular dichroism did not indicate any changes of the secondary structure of globular and fibrillar actin from denervated skeletal muscles. The matter that some conformational changes of the aromatic residues do in fact accompany denervation was confirmed by fluorescence studies but not by CD spectra.

[Spectroscopic study of myosin from denervated rabbit muscles].

Spectra of tryptophan UV-fluorescence and UV-absorption of myosin isolated 30 days after denervation of white skeletal muscles of rabbit were studied. It has been observed that fluorescence intensity of such myosin in the maximum decreases. This decrease becomes more pronounced after purification of protein from admixtures.

[Acridine orange inhibition of the ATPase activity of myosin and its fragments].

The cation dye acridine orange (AO) was shown to inhibit ATPase activity of myosin, DTNB-myosin and heavy meromyosin and not to influence that of EDTA-S-1 at low ionic force. The inhibiting effect is concerned with the presence of KCl in solution. The allosteric influence of AO on myosin ATPase activity is discussed and dependence of this effect on charge distribution on the surface of the protein molecule is considered.

[Superprecipitation of synthetic actomyosin after denervation].

Superprecipitation of synthetic actomyosin formed from intact myosin and actin extracted from rabbit white skeletal muscles after denervation was compared with that of intact synthetic actomyosin. Superprecipitation was characterized by two parameters: (1) the value of superprecipitation delta E determining an increase in the absorption from minimum to maximum values, and (2) the time required for the half-maximum increase (t1/2) which is inverse of the velocity constant. It was shown that delta E and the velocity constant decrease and t1/2 after denervation.

[Changes in structural and functional properties of actin in denervated rabbit skeletal muscles].

Amino acid composition of actin from white skeletal muscles of the rabbit was studied 14 and 50 days after denervation. The content of valine, histidine and tyrosine was shown to decrease and that of lysine and leucine to increase on the 14th day following denervation. The content of these amino acids was almost normalised on the 50th day.

[Letter: Effect of denervation on the anomalous behavior of acridine orange stained actin in solution].

Effect of superviscous state of AO stained actin in concentrated salts (KCI) significantly decreases two weeks after denervation. These changes of anomalous behaviour of stained action are partially reversible at the long time diasrophy. This phenomenon is suggested to be connected with the structural changes of "denervated" actin, which are reflected in the changes of protein electrostatic region.