Analysis of non-histone chromatin proteins in porcine malignant hyperthermia.

Non-histone chromatin proteins (NHCP) were isolated from skeletal muscle, left ventricle and liver of swine susceptible to malignant hyperthermia and from controls. These proteins were extracted with phenol buffers and fractionated by polyacrylamide gel electrophoresis. Isoelectrofocusing gel electrophoresis revealed quantitative differences in NHCP from skeletal muscle between disease and control groups. The high resolution of proteins by two-dimensional polyacrylamide gel electrophoresis showed a relative similarity between skeletal muscle, heart and liver although some differences could be discerned. Non-histone chromatin proteins of molecular weight 35,000-45,000, focusing between pH7 and 9, were increased in skeletal muscle nuclei derived from malignant hyperthermia-susceptible swine. These proteins appear to be important in the maturation of messenger RNA. No alterations were seen in either heart or liver. We conclude that an increase in NHCP which is associated with the processing of messenger RNA, may be important in the phenotypic expression in skeletal muscle of malignant hyperthermia in swine.