Leukotriene A4 hydrolase in human leukocytes. Purification and properties.
Leukotriene A4 hydrolase, a soluble enzyme catalyzing hydrolysis of the allylic epoxide leukotriene A4 to the dihydroxy acid leukotriene B4, was purified to apparent homogeneity from human leukocytes. The enzymatic reaction obeyed Michaelis-Menten saturation kinetics with respect to varying concentrations of leukotriene A4. An apparent KM value ranging between 20 and 30 microM was deduced from Eadie-Hofstee plots. Physical properties including molecular weight (68,000-70,000), amino acid composition, and aminoterminal sequence were determined. It was indicated that leukotriene A4 hydrolase is a monomeric protein, distinct from previously described epoxide hydrolases in liver.
D000596:Amino Acids / Q000032:analysis; D002852:Chromatography, Ion Exchange; D004851:Epoxide Hydrolases / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000201:enzymology*; D008970:Molecular Weight; D013347:Subcellular Fractions / Q000201:enzymology
D000596:Amino Acids; D004851:Epoxide Hydrolases; C043134:leukotriene A4 hydrolase