Fig. 3

Fig. 3 Titin immunoanalysis of patients with SRPK3/TTN myopathy.

Muscle biopsy lysates of individuals DI:1, DII:1, LII:1, XII:3, XIII:1 and YII:3 were analyzed using different anti-titin antibodies. a, SRPK3/TTN patients LII:1, YII:3, DII:1, XII:3 and XIII:1 showed a normal pattern of C-terminal titin proteolytic fragments (13, 15 and 18 kDa in size), ruling out a C-terminal titinopathy. b,c, Antibodies against the N-terminal titin (Z1Z2 TTN-1, b) and distal I-band of titin (F146.9B9, c) showed that the full-length titin band is missing or highly reduced in the patients with SRPK3/TTN myopathy (XIII:1, XII:3 and YII:3), but it is present in an unaffected relative TTNtv carrier (DI:1, father of DII:1) and a disease control also carrying a heterozygous TTNtv. This could be attributed to changes in N-terminal protein sequence or structure, or otherwise, protein modifications preventing antibody recognition. d, Coomassie staining also showed the absence or reduction of the high molecular weight band representing the full-length titin protein, whereas the NEB and MyHC bands were normal. Western blots were repeated twice, from the same muscle lysates. Full-length blots are provided as source data. MW, molecular weight; MyHC, myosin heavy chain; NEB, nebulin.

Source data