16751-02-3Relevant articles and documents
Engineering of a Plant Isoprenyl Diphosphate Synthase for Development of Irregular Coupling Activity
Gerasymenko, Iryna,Sheludko, Yuriy V.,Navarro Fuertes, Ismael,Schmidts, Volker,Steinel, Lara,Haumann, Elisabeth,Warzecha, Heribert
, (2021/11/09)
We performed mutagenesis on a regular isoprenyl diphosphate synthase (IDS), neryl diphosphate synthase from Solanum lycopersicum (SlNPPS), that has a structurally related analogue performing non-head-to-tail coupling of two dimethylallyl diphosphate (DMAPP) units, lavandulyl diphosphate synthase from Lavandula x intermedia (LiLPPS). Wild-type SlNPPS catalyses regular coupling of isopentenyl diphosphate (IPP) and DMAPP in cis-orientation resulting in the formation of neryl diphosphate. However, if the enzyme is fed with DMAPP only, it is able to catalyse the coupling of two DMAPP units and synthesizes two irregular monoterpene diphosphates; their structures were elucidated by the NMR analysis of their dephosphorylation products. One of the alcohols is lavandulol. The second compound is the trans-isomer of planococcol, the first example of an irregular cyclobutane monoterpene with this stereochemical configuration. The irregular activity of SlNPPS constitutes 0.4 % of its regular activity and is revealed only if the enzyme is supplied with DMAPP in the absence of IPP. The exchange of asparagine 88 for histidine considerably enhanced the non-head-to-tail coupling. While still only observed in the absence of IPP, irregular activity of the mutant reaches 13.1 % of its regular activity. The obtained results prove that regular IDS are promising starting points for protein engineering aiming at the development of irregular activities and leading to novel monoterpene structures.
Structural Characterization of Early Michaelis Complexes in the Reaction Catalyzed by (+)-Limonene Synthase from Citrus sinensis Using Fluorinated Substrate Analogues
Kumar, Ramasamy P.,Morehouse, Benjamin R.,Matos, Jason O.,Malik, Karan,Lin, Hongkun,Krauss, Isaac J.,Oprian, Daniel D.
, p. 1716 - 1725 (2017/04/04)
The stereochemical course of monoterpene synthase reactions is thought to be determined early in the reaction sequence by selective binding of distinct conformations of the geranyl diphosphate (GPP) substrate. We explore here formation of early Michaelis complexes of the (+)-limonene synthase [(+)-LS] from Citrus sinensis using monofluorinated substrate analogues 2-fluoro-GPP (FGPP) and 2-fluoroneryl diphosphate (FNPP). Both are competitive inhibitors for (+)-LS with KI values of 2.4 ± 0.5 and 39.5 ± 5.2 μM, respectively. The KI values are similar to the KM for the respective nonfluorinated substrates, indicating that fluorine does not significantly perturb binding of the ligand to the enzyme. FGPP and FNPP are also substrates, but with dramatically reduced rates (kcat values of 0.00054 ± 0.00005 and 0.00024 ± 0.00002 s-1, respectively). These data are consistent with a stepwise mechanism for (+)-LS involving ionization of the allylic GPP substrate to generate a resonance-stabilized carbenium ion in the rate-limiting step. Crystals of apo-(+)-LS were soaked with FGPP and FNPP to obtain X-ray structures at 2.4 and 2.2 ? resolution, respectively. The fluorinated analogues are found anchored in the active site through extensive interactions involving the diphosphate, three metal ions, and three active-site Asp residues. Electron density for the carbon chains extends deep into a hydrophobic pocket, while the enzyme remains mostly in the open conformation observed for the apoprotein. While FNPP was found in multiple conformations, FGPP, importantly, was in a single, relatively well-defined, left-handed screw conformation, consistent with predictions for the mechanism of stereoselectivity in the monoterpene synthases.
Phosphorylation of Isoprenoid Alcohols
Davisson, V. Jo,Woodside, Andrew B.,Neal, Timothy R.,Stremler, Kay E.,Muehlbacher, Manfred,Poulter, C. Dale
, p. 4768 - 4779 (2007/10/02)
Procedures for the synthesis and purification of 20 isoprenoid diphosphates and methanediphosphonate analogues from the corresponding alcohols are described.The alcohols are activated for phosphorylation by conversion of homoallylic systems to tosylates and allylic systems to halides.The activated intermediates are treated with tris(tetra-n-butylammonium) salts of pyrophosphoric, methanediphosphonic, or difluoromethanediphosphonic acid to obtain the corresponding esters in yields 34-80percent.Chromatography on cellulose is a general method for purification of isoprenoid diphosphates, and procedures are decribed for compounds with C5 to C20 hydrocarbon moieties.The displacement by pyrophosphate occurs with inversion of configuration, and the procedure can be used to prepare isoprenoid diphosphates with chiral C1 methylene groups in high optical purity from the corresponding alcohols.