Immunostaining of skeletal and cardiac muscle surface membrane with antibody against Duchenne muscular dystrophy peptide

Abstract

Duchenne muscular dystrophy (DMD) is a debilitating X-linked muscle disease. We have used sequence information from complementary DNA clones, derived from the gene that is deleted in DMD patients^1–3, to generate an antiserum that stains the surface membrane of intact human and mouse skeletal muscle, but not that of DMD patients and mdx mice⁴. Here we identify the protein reacting with this antiserum as a single component of relative molecular mass 210,000 (M_r = 210K) that fractionates with a low-ionic strength extract of intact human and mouse skeletal muscle. It is therefore distinct from the 400K protein found in the heavy microsomal fraction of normal muscle and identified as a putative product of the DMD gene⁵. We also analyse further the disease specificity of the antiserum. Positive staining is seen in normal controls, and in samples from patients with a wide range of muscular dystrophies other than DMD. Becker muscular dystrophy⁶, which is allelically related to DMD, was the only other exception, and gave a sporadic staining pattern. The demonstration of a specific defect in the surface membrane of DMD muscle fibres substantiates the hypothesis^7–10 that membrane lesions may initiate muscle degradation in DMD.