Isolation and characterization of the human liver ethanolamine kinase

Abstract Ethanolamine kinase was purified from human liver to apparent homogeneity and its properties were studied. The minimum molecular weight of the purified enzyme was estimated by SDS-PAGE to 42000 ± 2000 Da. The molecular weight of the native enzyme determined by Superose 12 (FPLC) gel filtration was 87000 ± 4000 Da, suggesting that ethanolamine kinase in human liver consists of two chains of the same or almost the same molecular weight. The titration of the active site normality showed 1.03 ± 0.05 active sites /chain. The K m value for ethanolamine was 0.25 ± 0.01 mM.