Fig. 1.

SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) analysis of titin isoforms in striated muscles of ground squirrel (Spermophilus undulatus); a modified view from (Vikhlyantsev and Podlubnaya 2008). 1 Myocardium (left ventricle), 2 m. soleus. Protein bands are indicated: heavy chains of myosin (MHC); nebulin–cytoskeletal protein of thin filaments; proteolytic fragments of titin (T2); intact titin (T1); isoforms of T1 (N2B, N2BA, N2A, NT). Vertical agarose-strengthened 1.9% polyacrylamide gel (14.5 × 16.0 × 0.15 cm) was used to separate the titin isoforms. Enlarged fragment of the gel with NT-titin bands is in the inset. As standards for estimation of molecular weights, the MHC (205 kDa), nebulin (770–890 kDa), titin-2 (2100–2400 kDa) of rabbit and human striated muscles were used (Wang et al. 1991; Krüger et al. 1991; Granzier and Wang 1993)