Barth M

References (11)

Title : Hexafluoroisopropyl carbamates as selective MAGL and dual MAGL\/FAAH inhibitors: biochemical and physicochemical properties - Barth_2022_ChemMedChem__
Author(s) : Barth M , Rudolph S , Kampschulze J , Meyer Zu Vilsendorf I , Hanekamp W , Mulac D , Langer K , Lehr M
Ref : ChemMedChem , : , 2022
Abstract : A series of hexafluoroisopropyl carbamates with indolyl-alkyl- and azaindolylalkyl-substituents at the carbamate nitrogen was synthesized and evaluated for inhibition of the endocannabinoid degrading enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). The synthesized derivatives with butyl to heptyl spacers between the heteroaryl and the carbamate moiety were inhibitors of both enzymes. For investigated compounds in which the alkyl chain was partially incorporated into a piperidine ring, different results were obtained. Compounds with a methylene spacer between the piperidine ring and the heteroaromatic system were found to be selective MAGL inhibitors, while an extension of the alkyl spacer to two to four atoms resulted in dual inhibition of FAAH/MAGL. The only small change in enzyme inhibitory activity with variation of the heteroaromatic system indicates that the reactive hexafluoro-isopropyl carbamate group is mainly responsible for the strength of the inhibitory effect of the compounds. Selected derivatives were also tested for hydrolytic stability in aqueous solution, liver homogenate and blood plasma as well as for aqueous solubility and for per-meability in a Caco-2 cell model. Some compounds showed a slightly higher MAGL inhibitory effect than the known selective MAGL inhibitor ABX-1431 and also partly surpassed this substance with regard to certain physicochemical and biochemical properties such as water solubility and cell permeability.
ESTHER : Barth_2022_ChemMedChem__
PubMedSearch : Barth_2022_ChemMedChem__
PubMedID: 35072346

Title : Aryl N-[w-(6-Fluoroindol-1-yl)alkyl]carbamates as Inhibitors of Fatty Acid Amide Hydrolase, Monoacylglycerol Lipase, and Butyrylcholinesterase: Structure-Activity Relationships and Hydrolytic Stability - Rudolph_2021_ACS.Omega_6_13466
Author(s) : Rudolph S , Dahlhaus H , Hanekamp W , Albers C , Barth M , Michels G , Friedrich D , Lehr M
Ref : ACS Omega , 6 :13466 , 2021
Abstract : A series of aryl N-[omega-(6-fluoroindol-1-yl)alkyl]carbamates with alkyl spacers of varying lengths between the indole and the carbamate group and with differently substituted aryl moieties at the carbamate oxygen were synthesized and tested for inhibition of the pharmacologically interesting serine hydrolases fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), butyrylcholinesterase (BuChE), and acetylcholinesterase (AChE). Furthermore, the chemical stability in an aqueous solution and the metabolic stability toward esterases in porcine liver homogenate and porcine blood plasma were determined. While most of the synthesized derivatives were potent inhibitors of FAAH, a considerable inhibition of MAGL and BuChE was elicited only by compounds with a high carbamate reactivity, as evidenced by a significant hydrolysis of these compounds in an aqueous solution. However, the high inhibitory potency of some compounds toward MAGL and BuChE, especially that of the ortho-carboxyphenyl derivative 37, could not be explained by chemical reactivity alone. Several of the carbamates studied possessed varying degrees of stability toward esterases from liver and blood plasma. In some cases, marked inactivation by the pseudo-esterase activity of plasma albumin was observed. Mass spectrometric studies showed that such carbamates formed covalent bonds with albumin at several sites.
ESTHER : Rudolph_2021_ACS.Omega_6_13466
PubMedSearch : Rudolph_2021_ACS.Omega_6_13466
PubMedID: 34056494

Title : A disulfide bridge in the calcium binding site of a polyester hydrolase increases its thermal stability and activity against polyethylene terephthalate - Then_2016_FEBS.Open.Bio_6_425
Author(s) : Then J , Wei R , Oeser T , Gerdts A , Schmidt J , Barth M , Zimmermann W
Ref : FEBS Open Bio , 6 :425 , 2016
Abstract : Elevated reaction temperatures are crucial for the efficient enzymatic degradation of polyethylene terephthalate (PET). A disulfide bridge was introduced to the polyester hydrolase TfCut2 to substitute its calcium binding site. The melting point of the resulting variant increased to 94.7 degreesC (wild-type TfCut2: 69.8 degreesC) and its half-inactivation temperature to 84.6 degreesC (TfCut2: 67.3 degreesC). The variant D204C-E253C-D174R obtained by introducing further mutations at vicinal residues showed a temperature optimum between 75 and 80 degreesC compared to 65 and 70 degreesC of the wild-type enzyme. The variant caused a weight loss of PET films of 25.0 +/- 0.8% (TfCut2: 0.3 +/- 0.1%) at 70 degreesC after a reaction time of 48 h. The results demonstrate that a highly efficient and calcium-independent thermostable polyester hydrolase can be obtained by replacing its calcium binding site with a disulfide bridge.
ESTHER : Then_2016_FEBS.Open.Bio_6_425
PubMedSearch : Then_2016_FEBS.Open.Bio_6_425
PubMedID: 27419048
Gene_locus related to this paper: thefu-q6a0i4

Title : Effect of Tris, MOPS, and phosphate buffers on the hydrolysis of polyethylene terephthalate films by polyester hydrolases - Schmidt_2016_FEBS.Open.Bio_6_919
Author(s) : Schmidt J , Wei R , Oeser T , Belisario-Ferrari MR , Barth M , Then J , Zimmermann W
Ref : FEBS Open Bio , 6 :919 , 2016
Abstract : The enzymatic degradation of polyethylene terephthalate (PET) occurs at mild reaction conditions and may find applications in environmentally friendly plastic waste recycling processes. The hydrolytic activity of the homologous polyester hydrolases LC cutinase (LCC) from a compost metagenome and TfCut2 from Thermobifida fusca KW3 against PET films was strongly influenced by the reaction medium buffers tris(hydroxymethyl)aminomethane (Tris), 3-(N-morpholino)propanesulfonic acid (MOPS), and sodium phosphate. LCC showed the highest initial hydrolysis rate of PET films in 0.2 m Tris, while the rate of TfCut2 was 2.1-fold lower at this buffer concentration. At a Tris concentration of 1 m, the hydrolysis rate of LCC decreased by more than 90% and of TfCut2 by about 80%. In 0.2 m MOPS or sodium phosphate buffer, no significant differences in the maximum initial hydrolysis rates of PET films by both enzymes were detected. When the concentration of MOPS was increased to 1 m, the hydrolysis rate of LCC decreased by about 90%. The activity of TfCut2 remained low compared to the increasing hydrolysis rates observed at higher concentrations of sodium phosphate buffer. In contrast, the activity of LCC did not change at different concentrations of this buffer. An inhibition study suggested a competitive inhibition of TfCut2 and LCC by Tris and MOPS. Molecular docking showed that Tris and MOPS interfered with the binding of the polymeric substrate in a groove located at the protein surface. A comparison of the K i values and the average binding energies indicated MOPS as the stronger inhibitor of the both enzymes.
ESTHER : Schmidt_2016_FEBS.Open.Bio_6_919
PubMedSearch : Schmidt_2016_FEBS.Open.Bio_6_919
PubMedID: 27642555

Title : Engineered bacterial polyester hydrolases efficiently degrade polyethylene terephthalate due to relieved product inhibition - Wei_2016_Biotechnol.Bioeng_113_1658
Author(s) : Wei R , Oeser T , Schmidt J , Meier R , Barth M , Then J , Zimmermann W
Ref : Biotechnol Bioeng , 113 :1658 , 2016
Abstract : Recent studies on the enzymatic degradation of synthetic polyesters have shown the potential of polyester hydrolases from thermophilic actinomycetes for modifying or degrading polyethylene terephthalate (PET). TfCut2 from Thermobifida fusca KW3 and LC-cutinase (LCC) isolated from a compost metagenome are remarkably active polyester hydrolases with high sequence and structural similarity. Both enzymes exhibit an exposed active site in a substrate binding groove located at the protein surface. By exchanging selected amino acid residues of TfCut2 involved in substrate binding with those present in LCC, enzyme variants with increased PET hydrolytic activity at 65 degrees C were obtained. The highest activity in hydrolyzing PET films and fibers were detected with the single variant G62A and the double variant G62A/I213S. Both variants caused a weight loss of PET films of more than 42% after 50 h of hydrolysis, corresponding to a 2.7-fold increase compared to the wild type enzyme. Kinetic analysis based on the released PET hydrolysis products confirmed the superior hydrolytic activity of G62A with a fourfold higher hydrolysis rate constant and a 1.5-fold lower substrate binding constant than those of the wild type enzyme. Mono-(2-hydroxyethyl) terephthalate is a strong inhibitor of TfCut2. A determination of the Rosetta binding energy suggested a reduced interaction of G62A with 2PET, a dimer of the PET monomer ethylene terephthalate. Indeed, G62A revealed a 5.5-fold lower binding constant to the inhibitor than the wild type enzyme indicating that its increased PET hydrolysis activity is the result of a relieved product inhibition by mono-(2-hydroxyethyl) terephthalate. Biotechnol. Bioeng. 2016;113: 1658-1665. (c) 2016 Wiley Periodicals, Inc.
ESTHER : Wei_2016_Biotechnol.Bioeng_113_1658
PubMedSearch : Wei_2016_Biotechnol.Bioeng_113_1658
PubMedID: 26804057
Gene_locus related to this paper: 9bact-g9by57 , thefu-q6a0i4

Title : A dual enzyme system composed of a polyester hydrolase and a carboxylesterase enhances the biocatalytic degradation of polyethylene terephthalate films - Barth_2016_Biotechnol.J_11_1082
Author(s) : Barth M , Honak A , Oeser T , Wei R , Belisario-Ferrari MR , Then J , Schmidt J , Zimmermann W
Ref : Biotechnol J , 11 :1082 , 2016
Abstract : TfCut2 from Thermobifida fusca KW3 and the metagenome-derived LC-cutinase are bacterial polyester hydrolases capable of efficiently degrading polyethylene terephthalate (PET) films. Since the enzymatic PET hydrolysis is inhibited by the degradation intermediate mono-(2-hydroxyethyl) terephthalate (MHET), a dual enzyme system consisting of a polyester hydrolase and the immobilized carboxylesterase TfCa from Thermobifida fusca KW3 was employed for the hydrolysis of PET films at 60 degrees C. HPLC analysis of the reaction products obtained after 24 h of hydrolysis showed an increased amount of soluble products with a lower proportion of MHET in the presence of the immobilized TfCa. The results indicated a continuous hydrolysis of the inhibitory MHET by the immobilized TfCa and demonstrated its advantage as a second biocatalyst in combination with a polyester hydrolase for an efficient degradation oft PET films. The dual enzyme system with LC-cutinase produced a 2.4-fold higher amount of degradation products compared to TfCut2 after a reaction time of 24 h confirming the superior activity of his polyester hydrolase against PET films.
ESTHER : Barth_2016_Biotechnol.J_11_1082
PubMedSearch : Barth_2016_Biotechnol.J_11_1082
PubMedID: 27214855
Gene_locus related to this paper: 9bact-g9by57 , thefu-1831

Title : Ca2+ and Mg2+ binding site engineering increases the degradation of polyethylene terephthalate films by polyester hydrolases from Thermobifida fusca - Then_2015_Biotechnol.J_10_592
Author(s) : Then J , Wei R , Oeser T , Barth M , Belisario-Ferrari MR , Schmidt J , Zimmermann W
Ref : Biotechnol J , 10 :592 , 2015
Abstract : Several bacterial polyester hydrolases are able to hydrolyze the synthetic polyester polyethylene terephthalate (PET). For an efficient enzymatic degradation of PET, reaction temperatures close to the glass transition temperature of the polymer need to be applied. The esterases TfH, BTA2, Tfu_0882, TfCut1, and TfCut2 produced by the thermophilic actinomycete Thermobifida fusca exhibit PET-hydrolyzing activity. However, these enzymes are not sufficiently stable in this temperature range for an efficient degradation of post-consumer PET materials. The addition of Ca2+ or Mg2+ cations to the enzymes resulted in an increase of their melting points between 10.8 and 14.1 degreesC determined by circular dichroism spectroscopy. The thermostability of the polyester hydrolases was sufficient to degrade semi-crystalline PET films at 65 degreesC in the presence of 10 mM Ca2+ and 10 mM Mg2+ resulting in weight losses of up to 12.9% after a reaction time of 48 h. The residues Asp174, Asp204, and Glu253 were identified by molecular dynamics simulations as potential binding residues for the two cations in TfCut2. This was confirmed by their substitution with arginine, resulting in a higher thermal stability of the corresponding enzyme variants. The generated variants of TfCut2 represent stabilized catalysts suitable for PET hydrolysis reactions performed in the absence of Ca2+ or Mg2+.
ESTHER : Then_2015_Biotechnol.J_10_592
PubMedSearch : Then_2015_Biotechnol.J_10_592
PubMedID: 25545638

Title : Efficient strategy for the molecular diagnosis of intellectual disability using targeted high-throughput sequencing - Redin_2014_J.Med.Genet_51_724
Author(s) : Redin C , Gerard B , Lauer J , Herenger Y , Muller J , Quartier A , Masurel-Paulet A , Willems M , Lesca G , El-Chehadeh S , Le Gras S , Vicaire S , Philipps M , Dumas M , Geoffroy V , Feger C , Haumesser N , Alembik Y , Barth M , Bonneau D , Colin E , Dollfus H , Doray B , Delrue MA , Drouin-Garraud V , Flori E , Fradin M , Francannet C , Goldenberg A , Lumbroso S , Mathieu-Dramard M , Martin-Coignard D , Lacombe D , Morin G , Polge A , Sukno S , Thauvin-Robinet C , Thevenon J , Doco-Fenzy M , Genevieve D , Sarda P , Edery P , Isidor B , Jost B , Olivier-Faivre L , Mandel JL , Piton A
Ref : Journal of Medical Genetics , 51 :724 , 2014
Abstract : BACKGROUND: Intellectual disability (ID) is characterised by an extreme genetic heterogeneity. Several hundred genes have been associated to monogenic forms of ID, considerably complicating molecular diagnostics. Trio-exome sequencing was recently proposed as a diagnostic approach, yet remains costly for a general implementation. METHODS: We report the alternative strategy of targeted high-throughput sequencing of 217 genes in which mutations had been reported in patients with ID or autism as the major clinical concern. We analysed 106 patients with ID of unknown aetiology following array-CGH analysis and other genetic investigations. Ninety per cent of these patients were males, and 75% sporadic cases. RESULTS: We identified 26 causative mutations: 16 in X-linked genes (ATRX, CUL4B, DMD, FMR1, HCFC1, IL1RAPL1, IQSEC2, KDM5C, MAOA, MECP2, SLC9A6, SLC16A2, PHF8) and 10 de novo in autosomal-dominant genes (DYRK1A, GRIN1, MED13L, TCF4, RAI1, SHANK3, SLC2A1, SYNGAP1). We also detected four possibly causative mutations (eg, in NLGN3) requiring further investigations. We present detailed reasoning for assigning causality for each mutation, and associated patients' clinical information. Some genes were hit more than once in our cohort, suggesting they correspond to more frequent ID-associated conditions (KDM5C, MECP2, DYRK1A, TCF4). We highlight some unexpected genotype to phenotype correlations, with causative mutations being identified in genes associated to defined syndromes in patients deviating from the classic phenotype (DMD, TCF4, MECP2). We also bring additional supportive (HCFC1, MED13L) or unsupportive (SHROOM4, SRPX2) evidences for the implication of previous candidate genes or mutations in cognitive disorders. CONCLUSIONS: With a diagnostic yield of 25% targeted sequencing appears relevant as a first intention test for the diagnosis of ID, but importantly will also contribute to a better understanding regarding the specific contribution of the many genes implicated in ID and autism.
ESTHER : Redin_2014_J.Med.Genet_51_724
PubMedSearch : Redin_2014_J.Med.Genet_51_724
PubMedID: 25167861
Gene_locus related to this paper: human-NLGN3

Title : Functional characterization and structural modeling of synthetic polyester-degrading hydrolases from Thermomonospora curvata - Wei_2014_AMB.Express_4_44
Author(s) : Wei R , Oeser T , Then J , Kuhn N , Barth M , Schmidt J , Zimmermann W
Ref : AMB Express , 4 :44 , 2014
Abstract : Thermomonospora curvata is a thermophilic actinomycete phylogenetically related to Thermobifida fusca that produces extracellular hydrolases capable of degrading synthetic polyesters. Analysis of the genome of T. curvata DSM43183 revealed two genes coding for putative polyester hydrolases Tcur1278 and Tcur0390 sharing 61% sequence identity with the T. fusca enzymes. Mature proteins of Tcur1278 and Tcur0390 were cloned and expressed in Escherichia coli TOP10. Tcur1278 and Tcur0390 exhibited an optimal reaction temperature against p-nitrophenyl butyrate at 60 degrees C and 55 degrees C, respectively. The optimal pH for both enzymes was determined at pH 8.5. Tcur1278 retained more than 80% and Tcur0390 less than 10% of their initial activity following incubation for 60 min at 55 degrees C. Tcur0390 showed a higher hydrolytic activity against poly(epsilon-caprolactone) and polyethylene terephthalate (PET) nanoparticles compared to Tcur1278 at reaction temperatures up to 50 degrees C. At 55 degrees C and 60 degrees C, hydrolytic activity against PET nanoparticles was only detected with Tcur1278. In silico modeling of the polyester hydrolases and docking with a model substrate composed of two repeating units of PET revealed the typical fold of alpha/beta serine hydrolases with an exposed catalytic triad. Molecular dynamics simulations confirmed the superior thermal stability of Tcur1278 considered as the main reason for its higher hydrolytic activity on PET.
ESTHER : Wei_2014_AMB.Express_4_44
PubMedSearch : Wei_2014_AMB.Express_4_44
PubMedID: 25405080
Gene_locus related to this paper: thecd-d1a9g5 , thecd-d1a2h1

Title : Turbidimetric analysis of the enzymatic hydrolysis of polyethylene terephthalate nanoparticles - Wei_2014_J.Mol.Catal.B.Enzym_103_72
Author(s) : Wei R , Oeser O , Barth M , Weigl N , Luebs A , Schulz-Siegmund M , Hacker MC , Zimmermann W
Ref : J Mol Catal B Enzym , 103 :72 , 2014
Abstract : The heterogeneous enzymatic hydrolysis of polyethylene terephthalate (PET) by a polyester hydrolase (TfCut2) from Thermobifida fusca KW3 was determined by measuring the change of intensity of transmitted light due to the scattering effect of PET nanoparticles immobilized in an agarose gel. Nanoparticles with a mean diameter between 100 and 160 nm were prepared from PET samples of different crystallinity to provide a large surface area for the adsorption of the enzyme. The turbidity decrease of the PET nanoparticle suspensions was correlated to the surface erosion process resulting from the enzymatic degradation, and enabled a direct estimation of the kinetic parameters of the enzymatic hydrolysis of PET based on a model for heterogeneous biocatalysis. A comparison of the hydrolysis rate constants and the adsorption equilibrium constants of the enzymatic hydrolysis of PET nanoparticles prepared from recycled PET granulate, film and fibres showed that the biodegradability of PET was mainly influenced by the mobility of the polyester chains, which determined the affinity and accessibility of the ester bonds to the enzyme. Differential scanning calorimetric analysis of the partially hydrolyzed PET nanoparticles provided indirect evidence for an endo-type hydrolytic mechanism of TfCut2 in the heterogeneous degradation of aromatic polyesters.
ESTHER : Wei_2014_J.Mol.Catal.B.Enzym_103_72
PubMedSearch : Wei_2014_J.Mol.Catal.B.Enzym_103_72

Title : Acetylcholine as a possible signaling molecule in embryonic stem cells: studies on survival, proliferation and death - Landgraf_2010_Chem.Biol.Interact_187_115
Author(s) : Landgraf D , Barth M , Layer PG , Sperling LE
Ref : Chemico-Biological Interactions , 187 :115 , 2010
Abstract : Acetylcholine (ACh) has always been regarded as a classical neurotransmitter that binds to nicotinic or muscarinic receptors and mediates signal transmission. The traditional view, that ACh acts solely as a neurotransmitter, has to be revised based on numerous findings demonstrating the existence of a non-neuronal cholinergic system. It is noteworthy that murine and human embryonic stem cells also synthesize ACh and express the enzyme acetylcholinesterase and muscarinic ACh receptors. Here, we investigated the possible role of ACh and AChRs in the regulation of embryonic stem cells. First, the expression of alpha3, alpha4, alpha7 and beta2 nicotinic receptor subunits in embryonic stem cells was investigated by RT-PCR. Second, in vitro studies have been conducted to assess the effects of ACh and its agonists on calcium dynamics, cell survival and proliferation. ACh and nicotine, but not muscarine could induce the mobilization of the intracellular Ca(2+). Interestingly, ACh increased the viability, but decreased the proliferation of embryonic stem cells. Our data provide evidence that ACh might exert its effect on stem cells by binding to specific receptors and modulating cell death and proliferation.
ESTHER : Landgraf_2010_Chem.Biol.Interact_187_115
PubMedSearch : Landgraf_2010_Chem.Biol.Interact_187_115
PubMedID: 20223227