A protein anomaly in erythrocyte membranes of patients with Duchenne muscular dystrophy.

Abstract

Raman spectroscopic comparisons of erythrocyte membranes from 20 patients with Duchenne muscular dystrophy and 8 age-matched controls indicate a prominent and consistent protein anomaly in the patient samples. CH-stretching signals from control membranes reveal a thermotropic transition at 15.6.degree. C, attributable to a protein/lipid phase that is lacking in dystrophic membranes. CH-stretching signals from control membranes also show a protein transititon at 39.degree. C [pH 7.4] that is shifted to 45.degree. in dystrophic membranes. A reduction in pH to 5.7 shifts this transition from 39.degree. to 7.degree. C in normal membranes and from 45.degree. to 24.degree. C in dystrophic membranes. The amide I/amide III regions indicate a significant proportion of .beta.-structured peptide in dystrophic but not normal membranes. Analysis of tyrosine signals indicates greater polar exposure of tyrosine hydroxyl groups in dystrophic vs. normal membranes. All of the differences between dystrophic and normal membranes are highly significant (P < 0.001).