Aschauer P

References (7)

Title : Structural Changes in the Cap of Rv0183\/mtbMGL Modulate the Shape of the Binding Pocket - Grininger_2021_Biomolecules_11_1299
Author(s) : Grininger C , Leypold M , Aschauer P , Pavkov-Keller T , Riegler-Berket L , Breinbauer R , Oberer M
Ref : Biomolecules , 11 :1299 , 2021
Abstract : doi:10.3390/biom11091299 Tuberculosis continues to be a major threat to the human population. Global efforts to eradicate the disease are ongoing but are hampered by the increasing occurrence of multidrug-resistant strains of Mycobacterium tuberculosis. Therefore, the development of new treatment, and the exploration of new druggable targets and treatment strategies, are of high importance. Rv0183/mtbMGL, is a monoacylglycerol lipase of M. tuberculosis and it is involved in providing fatty acids and glycerol as building blocks and as an energy source. Since the lipase is expressed during the dormant and active phase of an infection, Rv0183/mtbMGL is an interesting target for inhibition. In this work, we determined the crystal structures of a surface-entropy reduced variant K74A Rv0183/mtbMGL in its free form and in complex with a substrate mimicking inhibitor. The two structures reveal conformational changes in the cap region that forms a major part of the substrate/inhibitor binding region. We present a completely closed conformation in the free form and semi-closed conformation in the ligand-bound form. These conformations differ from the previously published, completely open conformation of Rv0183/mtbMGL. Thus, this work demonstrates the high conformational plasticity of the cap from open to closed conformations and provides useful insights into changes in the substrate-binding pocket, the target of potential small-molecule inhibitors.
ESTHER : Grininger_2021_Biomolecules_11_1299
PubMedSearch : Grininger_2021_Biomolecules_11_1299
PubMedID: 34572512
Gene_locus related to this paper: myctu-rv0183

Title : Identification of lipases with activity towards monoacylglycerol by criterion of conserved cap architectures - Riegler-Berket_2018_Biochim.Biophys.Acta_1863_679
Author(s) : Riegler-Berket L , Leitmeier A , Aschauer P , Dreveny I , Oberer M
Ref : Biochimica & Biophysica Acta , 1863 :679 , 2018
Abstract : Monoacylglycerol lipases (MGL) are a subclass of lipases that predominantly hydrolyze monoacylglycerol (MG) into glycerol and fatty acid. MGLs are ubiquitous enzymes across species and play a role in lipid metabolism, affecting energy homeostasis and signaling processes. Structurally, MGLs belong to the alpha/beta hydrolase fold family with a cap covering the substrate binding pocket. Analysis of the known 3D structures of human, yeast and bacterial MGLs revealed striking similarity of the cap architecture. Since MGLs from different organisms share very low sequence similarity, it is difficult to identify MGLs based on the amino acid sequence alone. Here, we investigated whether the cap architecture could be a characteristic feature of this subclass of lipases with activity towards MG and whether it is possible to identify MGLs based on the cap shape. Through database searches, we identified the structures of five different candidate alpha/beta hydrolase fold proteins with unknown or reported esterase activity. These proteins exhibit cap architecture similarities to known human, yeast and bacterial MGL structures. Out of these candidates we confirmed MGL activity for the protein LipS, which displayed the highest structural similarity to known MGLs. Two further enzymes, Avi_0199 and VC1974, displayed low level MGL activities. These findings corroborate our hypothesis that this conserved cap architecture can be used as criterion to identify lipases with activity towards MGs.
ESTHER : Riegler-Berket_2018_Biochim.Biophys.Acta_1863_679
PubMedSearch : Riegler-Berket_2018_Biochim.Biophys.Acta_1863_679
PubMedID: 29627382
Gene_locus related to this paper: 9bact-TtEst , agrvs-b9jym4 , bac25-mglp , bacsu-cbxnp , human-MGLL , symth-q67mr3 , vibch-VC1974 , yeast-mgll

Title : The crystal structure of monoacylglycerol lipase from M. tuberculosis reveals the basis for specific inhibition - Aschauer_2018_Sci.Rep_8_8948
Author(s) : Aschauer P , Zimmermann R , Breinbauer R , Pavkov-Keller T , Oberer M
Ref : Sci Rep , 8 :8948 , 2018
Abstract : Monoacylglycerol lipases (MGLs) are enzymes that hydrolyze monoacylglycerol into a free fatty acid and glycerol. Fatty acids can be used for triacylglycerol synthesis, as energy source, as building blocks for energy storage, and as precursor for membrane phospholipids. In Mycobacterium tuberculosis, fatty acids also serve as precursor for polyketide lipids like mycolic acids, major components of the cellular envelope associated to resistance for drug. We present the crystal structure of the MGL Rv0183 from Mycobacterium tuberculosis (mtbMGL) in open conformation. The structure reveals remarkable similarities with MGL from humans (hMGL) in both, the cap region and the alpha/beta core. Nevertheless, mtbMGL could not be inhibited with JZL-184, a known inhibitor of hMGL. Docking studies provide an explanation why the activity of mtbMGL was not affected by the inhibitor. Our findings suggest that specific inhibition of mtbMGL from Mycobacterium tuberculosis, one of the oldest recognized pathogens, is possible without influencing hMGL.
ESTHER : Aschauer_2018_Sci.Rep_8_8948
PubMedSearch : Aschauer_2018_Sci.Rep_8_8948
PubMedID: 29895832
Gene_locus related to this paper: myctu-rv0183

Title : Monoacylglycerol Lipases Act as Evolutionarily Conserved Regulators of Non-oxidative Ethanol Metabolism - Heier_2016_J.Biol.Chem_291_11865
Author(s) : Heier C , Taschler U , Radulovic M , Aschauer P , Eichmann TO , Grond S , Wolinski H , Oberer M , Zechner R , Kohlwein SD , Zimmermann R
Ref : Journal of Biological Chemistry , 291 :11865 , 2016
Abstract : Fatty acid ethyl esters (FAEEs) are non-oxidative metabolites of ethanol that accumulate in human tissues upon ethanol intake. Although FAEEs are considered as toxic metabolites causing cellular dysfunction and tissue damage, the enzymology of FAEE metabolism remains poorly understood. In this study, we used a biochemical screen in Saccharomyces cerevisiae to identify and characterize putative hydrolases involved in FAEE catabolism. We found that Yju3p, the functional orthologue of mammalian monoacylglycerol lipase (MGL), contributes >90% of cellular FAEE hydrolase activity, and its loss leads to the accumulation of FAEE. Heterologous expression of mammalian MGL in yju3Delta mutants restored cellular FAEE hydrolase activity and FAEE catabolism. Moreover, overexpression or pharmacological inhibition of MGL in mouse AML-12 hepatocytes decreased or increased FAEE levels, respectively. FAEEs were transiently incorporated into lipid droplets (LDs) and both Yju3p and MGL co-localized with these organelles. We conclude that the storage of FAEE in inert LDs and their mobilization by LD-resident FAEE hydrolases facilitate a controlled metabolism of these potentially toxic lipid metabolites.
ESTHER : Heier_2016_J.Biol.Chem_291_11865
PubMedSearch : Heier_2016_J.Biol.Chem_291_11865
PubMedID: 27036938

Title : Crystal structure of the Saccharomyces cerevisiae monoglyceride lipase Yju3p - Aschauer_2016_Biochim.Biophys.Acta_1861_462
Author(s) : Aschauer P , Rengachari S , Lichtenegger J , Schittmayer M , Das KM , Mayer N , Breinbauer R , Birner-Gruenberger R , Gruber CC , Zimmermann R , Gruber K , Oberer M
Ref : Biochimica & Biophysica Acta , 1861 :462 , 2016
Abstract : Monoglyceride lipases (MGLs) are a group of alpha/beta-hydrolases that catalyze the hydrolysis of monoglycerides (MGs) into free fatty acids and glycerol. This reaction serves different physiological functions, namely in the last step of phospholipid and triglyceride degradation, in mammalian endocannabinoid and arachidonic acid metabolism, and in detoxification processes in microbes. Previous crystal structures of MGLs from humans and bacteria revealed conformational plasticity in the cap region of this protein and gave insight into substrate binding. In this study, we present the structure of a MGL from Saccharomyces cerevisiae called Yju3p in its free form and in complex with a covalently bound substrate analog mimicking the tetrahedral intermediate of MG hydrolysis. These structures reveal a high conservation of the overall shape of the MGL cap region and also provide evidence for conformational changes in the cap of Yju3p. The complex structure reveals that, despite the high structural similarity, Yju3p seems to have an additional opening to the substrate binding pocket at a different position compared to human and bacterial MGL. Substrate specificities towards MGs with saturated and unsaturated alkyl chains of different lengths were tested and revealed highest activity towards MG containing a C18:1 fatty acid.
ESTHER : Aschauer_2016_Biochim.Biophys.Acta_1861_462
PubMedSearch : Aschauer_2016_Biochim.Biophys.Acta_1861_462
PubMedID: 26869448
Gene_locus related to this paper: yeast-mgll

Title : Purification, crystallization and preliminary X-ray diffraction analysis of a soluble variant of the monoglyceride lipase Yju3p from the yeast Saccharomyces cerevisiae - Rengachari_2015_Acta.Crystallogr.F.Struct.Biol.Commun_71_243
Author(s) : Rengachari S , Aschauer P , Sturm C , Oberer M
Ref : Acta Crystallographica F Struct Biol Commun , 71 :243 , 2015
Abstract : The protein Yju3p is the orthologue of monoglyceride lipases in the yeast Saccharomyces cerevisiae. A soluble variant of this lipase termed s-Yju3p (38.3 kDa) was generated and purified to homogeneity by affinity and size-exclusion chromatography. s-Yju3p was crystallized in a vapour-diffusion setup at 293 K and a complete data set was collected to 2.4 A resolution. The crystal form was orthorhombic (space group P212121), with unit-cell parameters a = 77.2, b = 108.6, c = 167.7 A. The asymmetric unit contained four molecules with a solvent content of 46.4%.
ESTHER : Rengachari_2015_Acta.Crystallogr.F.Struct.Biol.Commun_71_243
PubMedSearch : Rengachari_2015_Acta.Crystallogr.F.Struct.Biol.Commun_71_243
PubMedID: 25664804
Gene_locus related to this paper: yeast-mgll

Title : Conformational plasticity and ligand binding of bacterial monoacylglycerol lipase - Rengachari_2013_J.Biol.Chem_288_31093
Author(s) : Rengachari S , Aschauer P , Schittmayer M , Mayer N , Gruber K , Breinbauer R , Birner-Gruenberger R , Dreveny I , Oberer M
Ref : Journal of Biological Chemistry , 288 :31093 , 2013
Abstract : Monoacylglycerol lipases (MGLs) play an important role in lipid catabolism across all kingdoms of life by catalyzing the release of free fatty acids from monoacylglycerols. The three-dimensional structures of human and a bacterial MGL were determined only recently as the first members of this lipase family. In addition to the alpha/beta-hydrolase core, they showed unexpected structural similarities even in the cap region. Nevertheless, the structural basis for substrate binding and conformational changes of MGLs is poorly understood. Here, we present a comprehensive study of five crystal structures of MGL from Bacillus sp. H257 in its free form and in complex with different substrate analogs and the natural substrate 1-lauroylglycerol. The occurrence of different conformations reveals a high degree of conformational plasticity of the cap region. We identify a specific residue, Ile-145, that might act as a gatekeeper restricting access to the binding site. Site-directed mutagenesis of Ile-145 leads to significantly reduced hydrolase activity. Bacterial MGLs in complex with 1-lauroylglycerol, myristoyl, palmitoyl, and stearoyl substrate analogs enable identification of the binding sites for the alkyl chain and the glycerol moiety of the natural ligand. They also provide snapshots of the hydrolytic reaction of a bacterial MGL at different stages. The alkyl chains are buried in a hydrophobic tunnel in an extended conformation. Binding of the glycerol moiety is mediated via Glu-156 and water molecules. Analysis of the structural features responsible for cap plasticity and the binding modes of the ligands suggests conservation of these features also in human MGL.
ESTHER : Rengachari_2013_J.Biol.Chem_288_31093
PubMedSearch : Rengachari_2013_J.Biol.Chem_288_31093
PubMedID: 24014019
Gene_locus related to this paper: bac25-mglp