Creatine Kinase BB is a cytoplasmic enzyme involved in energy homeostasis. The encoded protein reversibly catalyzes the transfer of phosphate between ATP and various phosphogens such as creatine phosphate. It acts as a homodimer in brain as well as in other tissues, and as a heterodimer with a similar muscle isozyme in heart. The encoded protein is a member of the ATP:guanido phosphotransferase protein family. A pseudogene of this gene has been characterized Synonyms: Creatine kinase B-type, EC 2.7.3.2, Creatine kinase B chain, B-CK, CKB, CKBB, CKBBI