The effect of crosslinking of thin filament with glutaraldehyde on the contractility of muscle fiber

The effect of crosslinking of F-actin with glutaraldehyde on the contractility of muscle ghost fiber containing reconstituted thin filament (i.e. F-actin-tropomyosin-troponin complex) and irrigated with myosin was investigated. The results show that: (i) crosslinking inhibited development of isometric tension and shortening of the fiber in the presence of MgATP, (ii) superprecipitation of the complex of myosin with crosslinked thin filament was considerably delayed, (iii) crosslinking inhibited neither binding of myosin heads to the filament nor activation of myosin ATPase. It is suggested that alterations of actin structure due to the formation of intra- and/or intermonomer crosslinks can essentially affect the process of contractility.