Abstract Ca 2+-activated protease (CAF) digestion of glycerinated nemaline myopathy
muscle removed the electron-dense material covering rods and Z-lines and exposed
longitudinal backbone filaments, 6–7 nm wide, which span the lengths of the original rods.
Decoration of the exposed filaments (which are responsible for the periodicity parallel to the
long axis of intact namaline rods) with heavy meromyosin (HMM) proved they are actin
filaments. After CAF treatment, cross-striated periodical patterns in longitudinal sections and …