Physical and serological comparison and hybridization of isozymes of creatine kinase from primates

Abstract

1. 1. The isozymes of creatine kinase from monkey muscle and brain and human muscle were purified to apparent homogeneity while the heart specific isozyme from monkey was partially purified. 2. 2. Analysis of pH optima, isoelectric points, amino acid content, thermal inactivation, molecular weights, and reactivity towards DTNB and NDAZ suggest the following conclusions: creatine kinase from monkey brain and monkey muscle arc structurally very different enzymes. Creatine kinase from monkey muscle and human muscle display several similar properties but may be distinguished by thermal inactivation and amino acid content. 3. 3. Immunological analysis with antibody against creatine kinase from monkey muscle supports the conclusion that monkey brain and monkey muscle are distinct enzymes and that monkey muscle and human muscle are closely related. 4. 4. Hybrid isozymes were prepared from monkey muscle or human muscle isozymes and monkey brain isozyme. 5. 5. Several experimental observations suggest that while the heart-specific isozyme is a hybrid of the brain and muscle isozyme, it is conformationally more like the brain isozyme than the muscle isozyme.