Western blot analysis. A: Immunoblots of heart extracts prepared from wt,
mdx, and DMD-null mice. Note: Both Dp427 and
Dp71 were present in the hearts of wt mice, only Dp71 was present in the
mdx mice, and neither was present in the
DMD-null mice. The asterisk indicates a nonspecific signal. B:
Immunoblots of subcellular fractions after separating heart homogenates from wt mice
by iodixanol density-gradient centrifugation. Note: Dp427 was present in the cardiac
sarcolemmal (#3, 4) and intracellular membrane fractions (#6. 7), while Dp71 was
present in intracellular membrane fractions (#6. 7).