The partial purification and properties of hydroxylysine kinase from rat liver.

Hydroxylysine kinase (guanosine triphosphate:5hydroxyL-lysine 0-phosphotransferase; EC 2.7.1.-) has been purified 1200-fold from rat liver and its properties partially elucidated. The enzyme catalyzes the phosphorylation of allohydroxy-L-lysine and hydroxy-L-lysine with an apparent K, N 6 PM, but has no activity with either of the D isomers. The maximum velocity with allohydroxy-L-lysine was 1.5 to 3 times greater than with hydroxy-L-lysine. GTP or hypoxanthine triphosphate, serve as the phosphate donor. Mg2+ is specifically required for the reaction while both Mn2f and Zn2+ are inhibitory. The active phosphorylating agent appears to be the MgGTPZcomplex with guanosine diphosphate as the nucleotide product. The kinase is present in the liver or kidney, or both, of rats, mice, chickens, bovine, rabbits, and two species of primates.