Hsp27-2D-gel electrophoresis is a diagnostic tool to differentiate primary desminopathies from myofibrillar myopathies

Small heat shock proteins prevent abnormal protein folding and accumulation. We analyzed the expression of hsp27 and alpha B-crystallin in skeletal muscle specimens of patients with desminopathies, plectinopathies, myotilinopathy, and other myofibrillar myopathies by means of differential centrifugation, 2D-gel electrophoresis, Western blotting, and mass spectrometry. Hsp27-P82 and -P15 as well as alpha B-crystallin-P59 and -P45 are the major serine phosphorylation isoforms in normal and diseased human skeletal muscle. 2D-gel-electrophoresis revealed spots of hsp27 in a range of pH 5.3-6.4 in samples of all skeletal muscle specimens, except for the seven desminopathies. They indicated a shift of the main hsp27-spot to alkaline pH degrees, which may help to differentiate primary desminopathies from other myopathies with structural pathology of the desmin cytoskeleton. (c) 2005 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.