CHARACTERIZATION OF MYOCARDIAL PROTEIN-COMPOSITION IN DILATED CARDIOMYOPATHY BY 2-DIMENSIONAL GEL-ELECTROPHORESIS

In order to identify alterations in the myocardial protein pattern tha t characterize dilated cardiomyopathy (DCM), we compared, by two-dimen sional gel electrophoresis, right atrial protein patterns from five pa tients with DCM and four with normal left ventricular function (two ge ls per patient). Using computer assisted analysis (PDQUEST; 4.1) we fo und reproducible protein patterns in the 18 gels (23 x 30 cm, pH 4-9, molecular weight 10-150 kDa). In the two gels from the same patient, 9 1 % of proteins were identical in their position in the pattern and th e relative intensities of these protein species correlated with r = 0. 85. Three hundred and two +/- 50 protein species were found in several gels, 186 in all 18 gels. Seven proteins in the DCM group were decrea sed in their relative intensity by > 100%, six were increased by >100% . Significant quantitative differences between DCM and control patient s were found for 25 protein species. Based on seven external marker pr oteins, a pH and molecular weight value could be calculated for each p rotein. So far, 30 protein species have been identified by antibodies, amino acid analysis or sequencing procedures. From the 25 proteins th at are significantly different between DCM and controls, three have be en identified Expression of the mitochondrial creatine kinase and alph a cristallin B chain was significantly increased in DCM; the malate de hydrogenase family was also significantly decreased in DCM. Two-dimens ional electrophoresis appears to be a powerful method for the detectio n of disease-associated alterations in the myocardial protein pattern.