Enables creatine kinase activity. Predicted to be involved in cellular chloride ion homeostasis and phosphocreatine biosynthetic process. Located in myelin sheath. Is active in mitochondrion. Is expressed in several structures, including alimentary system; central nervous system; genitourinary system; musculature; and sensory organ. Orthologous to human CKB (creatine kinase B). [provided by Alliance of Genome Resources, Apr 2022]