title: A comparative study of human muscle and brain creatine kinases expressed in Escherichia coli.
abstract: We report the expression of the human muscle (CK-MM) and brain (CK-BB) creatine kinases in Escherichia coli. The proteins have been purified to apparent homogeneity and several of their physical and kinetic properties investigated. In the process, we have conclusively verified the correct DNA sequence of the genes encoding the respective isozymes, and determined the correct primary structure and mass of the gene products. Alignment of the primary sequences of these two enzymes shows 81% sequence identity with each other, and no obvious gross structural differences. However, Western blot analyses demonstrated the general lack of antigenic cross-reactivity between these isozymes. Preliminary kinetic analyses show the K(m) and k(cat) values for the creatine and MgATP substrates are similar to values reported for other isozymes from various tissues and organisms. The human muscle and brain CKs do not, however, exhibit the synergism of substrate binding that is observed, for example, in rabbit muscle creatine kinase.
authors.affiliation: Department of Pharmaceutical Chemistry, University of California, San Francisco 94143, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Chen
authors.forename: C B
authors.initials: CB
authors.lastname: White
authors.forename: P C
authors.initials: PC
authors.lastname: Babbitt
authors.forename: M J
authors.initials: MJ
authors.lastname: McLeish
authors.forename: G L
authors.initials: GL
authors.lastname: Kenyon
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology*; D003001:Cloning, Molecular; D003402:Creatine Kinase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D011994:Recombinant Proteins; D003402:Creatine Kinase