Collect. Czech. Chem. Commun. 1999, 64, 559-570

Isoenzymes of GMP Kinase from L1210 Cells: Isolation and Characterization

Romana Krejčová, Květoslava Horská, Ivan Votruba* and Antonín Holý

Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague 6, Czech Republic


Guanylate kinase from a mouse leukemic L1210 cells has been purified nearly to homogeneity for the first time. It consists of five isoenzymes with pI 5.95, 5.50, 5.08, 4.83 and 4.51, respectively. The native enzyme is a monomer with a relative molecular mass 25 000. The kinetic constants Km, Vmax and kcat/Km of isoenzymes were estimated. The purified GMP kinase is absolutely specific to GMP and/or dGMP as phosphate acceptor but has a broad specificity to nucleoside 5'-triphosphates as phosphate donors.

Keywords: GMP kinase; Isoenzymes; Nucleotide kinase; Phosphorylation; Nucleotides; L1210 cells; Enzymes, isolation; Phosphates.