"costameres" - 1 õppematerjal

Liha töötlemine

by proteinacious filaments, known as inter- each) and two sets of light chains (14,000– mediate filaments. Outermost myofibrils are 20,000 daltons). One of the light chains is attached to the cell membrane (sarcolemma) required for enzymatic activity, and the other by intermediate filaments that interact not has regulatory functions. only with the Z-line, but also with structures Actin is the second-most abundant protein at the sarcolemma known as costameres in the myofibril, accounting for approxi- (Robson et al. 2004). mately 20% of the total protein in the myo- Myofibrils are made up of many myofila- fibril. Actin is a globular protein (G-actin) ments, of which there are two major types, that polymerizes to form filaments (F-actin). classified as thick and thin filaments. There G-actin has a molecular weight of approxi- is also a third filament system composed pri- mately 42,000