| Structural highlights
Function
[LKHA4_HUMAN] Epoxide hydrolase that catalyzes the final step in the biosynthesis of the proinflammatory mediator leukotriene B4. Has also aminopeptidase activity.[1] [2] [3] [4] [5] [6] [7]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Leukotriene A4 (LTA4, 5S-trans-5,6-oxido-7,9-trans-11,14-cis-eicosatetraenoic acid) hydrolase (LTA4H)/aminopeptidase is a bifunctional zinc metalloenzyme that catalyzes the final and rate-limiting step in the biosynthesis of leukotriene B4 (LTB4, 5S,12R-dihydroxy-6,14-cis-8,10-trans-eicosatetraenoic acid), a classical chemoattractant and immune modulating lipid mediator. Two chemical features are key to the bioactivity of LTB4, namely, the chirality of the 12R-hydroxyl group and the cis-trans-trans geometry of the conjugated triene structure. From the crystal structure of LTA4H, a hydrophilic patch composed of Gln-134, Tyr-267, and Asp-375 was identified in a narrow and otherwise hydrophobic pocket, believed to bind LTA4. In addition, Asp-375 belongs to peptide K21, a previously characterized 21-residue active site-peptide to which LTA4 binds during suicide inactivation. In the present report we used site-directed mutagenesis and x-ray crystallography to show that Asp-375, but none of the other candidate residues, is specifically required for the epoxide hydrolase activity of LTA4H. Thus, mutation of Asp-375 leads to a selective loss of the enzyme's ability to generate LTB4 whereas the aminopeptidase activity is preserved. We propose that Asp-375, possibly assisted by Gln-134, acts as a critical determinant for the stereoselective introduction of the 12R-hydroxyl group and thus the biological activity of LTB4.
Leukotriene A4 hydrolase: selective abrogation of leukotriene B4 formation by mutation of aspartic acid 375.,Rudberg PC, Tholander F, Thunnissen MM, Samuelsson B, Haeggstrom JZ Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4215-20. Epub 2002 Mar 26. PMID:11917124[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Odlander B, Claesson HE, Bergman T, Radmark O, Jornvall H, Haeggstrom JZ. Leukotriene A4 hydrolase in the human B-lymphocytic cell line Raji: indications of catalytically divergent forms of the enzyme. Arch Biochem Biophys. 1991 May 15;287(1):167-74. PMID:1897988
- ↑ Toh H, Minami M, Shimizu T. Molecular evolution and zinc ion binding motif of leukotriene A4 hydrolase. Biochem Biophys Res Commun. 1990 Aug 31;171(1):216-21. PMID:1975494
- ↑ 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. PMID:2244921
- ↑ Thunnissen MM, Andersson B, Samuelsson B, Wong CH, Haeggstrom JZ. Crystal structures of leukotriene A4 hydrolase in complex with captopril and two competitive tight-binding inhibitors. FASEB J. 2002 Oct;16(12):1648-50. Epub 2002 Aug 7. PMID:12207002 doi:10.1096/fj.01-1017fje
- ↑ Rudberg PC, Tholander F, Thunnissen MM, Samuelsson B, Haeggstrom JZ. Leukotriene A4 hydrolase: selective abrogation of leukotriene B4 formation by mutation of aspartic acid 375. Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4215-20. Epub 2002 Mar 26. PMID:11917124 doi:10.1073/pnas.072090099
- ↑ Rudberg PC, Tholander F, Andberg M, Thunnissen MM, Haeggstrom JZ. Leukotriene A4 hydrolase: identification of a common carboxylate recognition site for the epoxide hydrolase and aminopeptidase substrates. J Biol Chem. 2004 Jun 25;279(26):27376-82. Epub 2004 Apr 12. PMID:15078870 doi:10.1074/jbc.M401031200
- ↑ Tholander F, Muroya A, Roques BP, Fournie-Zaluski MC, Thunnissen MM, Haeggstrom JZ. Structure-based dissection of the active site chemistry of leukotriene A4 hydrolase: implications for M1 aminopeptidases and inhibitor design. Chem Biol. 2008 Sep 22;15(9):920-9. PMID:18804029 doi:10.1016/j.chembiol.2008.07.018
- ↑ Rudberg PC, Tholander F, Thunnissen MM, Samuelsson B, Haeggstrom JZ. Leukotriene A4 hydrolase: selective abrogation of leukotriene B4 formation by mutation of aspartic acid 375. Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4215-20. Epub 2002 Mar 26. PMID:11917124 doi:10.1073/pnas.072090099
|
