Leukotriene A4 hydrolase: a zinc metalloenzyme.
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Haeggstrom JZ, Wetterholm A, Shapiro R, Vallee BL, Samuelsson B
Leukotriene A4 hydrolase: a zinc metalloenzyme.
Biochem Biophys Res Commun. 1990 Nov 15;172(3):965-70.
- PubMed ID
- 2244921 [ View in PubMed]
- Abstract
Purified human leukotriene A4 hydrolase is shown to contain 1 mol of zinc per mol of enzyme, as determined by atomic absorption spectrometry. The enzyme is inhibited dose-dependently by the chelating agents 8-hydroxy-quinoline-5-sulfonic acid, and 1,10-phenanthroline with KI values of about 2 and 8 x 10(-4) M, respectively, whereas dipicolinic acid and EDTA are ineffective in this respect. The inhibition by 1,10-phenanthroline is time-dependent, and at a concentration of 5 mM, 50% inhibition of enzyme (3 x 10(-7) M) occurs after about 15 min. The zinc atom of leukotriene A4 hydrolase can be removed by dialysis against 1,10-phenanthroline which results in loss of enzyme activity. The catalytic activity is almost completely restored by the addition of stoichiometric amounts of Zn2+ or Co2+.