89198-07-2Relevant academic research and scientific papers
Structural Basis for the Catalytic Mechanism of Ethylenediamine- N, N′-disuccinic Acid Lyase, a Carbon-Nitrogen Bond-Forming Enzyme with a Broad Substrate Scope
Poddar, Harshwardhan,De Villiers, Jandré,Zhang, Jielin,Puthan Veetil, Vinod,Raj, Hans,Thunnissen, Andy-Mark W. H.,Poelarends, Gerrit J.
, p. 3752 - 3763 (2018/05/23)
The natural aminocarboxylic acid product ethylenediamine-N,N′-disuccinic acid [(S,S)-EDDS] is able to form a stable complex with metal ions, making it an attractive biodegradable alternative for the synthetic metal chelator ethylenediaminetetraacetic acid (EDTA), which is currently used on a large scale in numerous applications. Previous studies have demonstrated that biodegradation of (S,S)-EDDS may be initiated by an EDDS lyase, converting (S,S)-EDDS via the intermediate N-(2-aminoethyl)aspartic acid (AEAA) into ethylenediamine and two molecules of fumarate. However, current knowledge of this enzyme is limited because of the absence of structural data. Here, we describe the identification and characterization of an EDDS lyase from Chelativorans sp. BNC1, which has a broad substrate scope, accepting various mono- and diamines for addition to fumarate. We report crystal structures of the enzyme in an unliganded state and in complex with formate, succinate, fumarate, AEAA, and (S,S)-EDDS. The structures reveal a tertiary and quaternary fold that is characteristic of the aspartase/fumarase superfamily and support a mechanism that involves general base-catalyzed, sequential two-step deamination of (S,S)-EDDS. This work broadens our understanding of mechanistic diversity within the aspartase/fumarase superfamily and will aid in the optimization of EDDS lyase for asymmetric synthesis of valuable (metal-chelating) aminocarboxylic acids.
Purification and characterization of a lyase from the EDTA-degrading bacterial strain DSM 9103 that catalyzes the splitting of [S,S]-ethylenediaminedisuccinate, a structural isomer of EDTA
Witschel, Margarete,Egli, Thomas
, p. 419 - 428 (2007/10/03)
The bacterial strain DSM 9103, able to utilize EDTA as a sole source of carbon, nitrogen, and energy, is also capable to grow with [S,S]-ethylenediaminedisuccinate ([S,S]-EDDS), a structural isomer of EDTA. In cell-free extracts of [S,S]-EDDS-grown bacteria, [S,S]-EDDS degradation was observed in the absence of any cofactors. An enzyme was purified 41-fold that catalyzed the non-hydrolytic splitting of [S,S]-EDDS leading to the formation of fumarate and N-(2-aminoethyl) aspartic acid. These data strongly suggest that the enzyme belongs to the group of carbon-nitrogen lyases. The splitting reaction was reversible, and an equilibrium constant of approximately 43.0 10-1 M was determined. Out of the three stereo-isomers of EDDS, [S,S]- and [R,S]-EDDS were accepted as substrates by the lyase, whereas [R,R]-EDDS remained unchanged in assays with both cell-free extracts and pure enzyme. The enzyme catalyzed the transformation of free [S,S]-EDDS and of [S,S]-EDDS-metal complexes with stability constant lower than 10, namely of MgEDDS, CaEDDS, BaEDDS and to a small extent also of MnEDDS; Fe(III)EDDS, NiEDDS, CuEDDS, CoEDDS and ZnEDDS were not transformed.
Reactivity Studies of Chelated Maleate Ion: Stereoselectivity and Structural Correlations
Hammershoei, Anders,Sargeson, Alan M.,Steffen, William L.
, p. 2819 - 2837 (2007/10/02)
cobalt(III) ion (Λ-+ (1)) undergoes parallel OH- catalyzed reactions in aqueous solutions, first order in ->, to give stereospecific addition of a 2-aminoethaneaminato ion at the chelated olefin center and thereby (R)-N-(2-aminoethyl)aspartate (R-aea) bound as a quadridentate in Λ-mer(5,5)-+ (3) (k = 0.09 M-1 s-1, 25 deg C, μ = 1 M).The other path (k = 0.36 M-1 s-1) produced cis- and trans- complexes (19, 20) where the ring-opened monodentate ligand is unreactive.Similar stereoselectivity was observed for the reaction in liquid NH3 and dimethyl sulfoxide without ring opening.Equilibrium studies established that the fac(5,5)-+ isomer was more stable (96percent) than the mer isomer (4percent) produced by kinetic control.In the alkaline conditions the mer isomer also dissociates a carboxylate group and isomerizes about the cobalt center.The kinetics of this process were also followed.X-ray crystallographic analyses of the Λ-PF6*2H2O (I), racemic ClO4*2H2O (II), and Δ-fac(5,5)-BCS*3H2O (III) (BCS- = (+)589-α-bromocamphorsulfonate anion) salts were carried out to determine their connectivities and absolute configuration by the anomalous dispersion method.For I: space group P21; a = 11.629(6) Angstroem, b = 7.701(4) Angstroem, c = 9.379(4) Angstroem, β = 97.18(1) deg, Z = 2, 4336 reflections (F2 >= 3.0?(F2)), residual R1 = 0.045.For II: space group P21/c; a = 7.191(1) Angstroem, b = 10.915(2) Angstroem, c = 20.723(6) Angstroem, β = 91.41(1) deg, Z = 4, 4796 reflections (F2 >= 3.0?(F2)), residual R1 = 0.045.For III: space group P1; a = 6.976(1) Angstroem, b = 7.242(1) Angstroem; c = 14.248(2) Angstroem, α = 76.89(1) deg, β = 84.61(1) deg, γ = 70.86(1) deg, Z=1, 4731 reflections (F2 >= 3.0?(F2)), residual R1 = 0.040.The absolute configuration of the complex cation was also deduced from that of the BCS- anion.The chiral N-(2-aminoethyl)aspartate was biologically inactive in an aspergillomarasmine sense, but the results in general provide some support for Glusker's ferrous wheel mechanism for aconitase.
