eprintid: 10194395 rev_number: 9 eprint_status: archive userid: 699 dir: disk0/10/19/43/95 datestamp: 2024-08-21 13:52:49 lastmod: 2024-08-21 13:52:49 status_changed: 2024-08-21 13:52:49 type: article metadata_visibility: show sword_depositor: 699 creators_name: Rios-Solis, L creators_name: Bayir, N creators_name: Halim, M creators_name: Du, C creators_name: Ward, JM creators_name: Baganz, F creators_name: Lye, GJ title: Non-linear kinetic modelling of reversible bioconversions: Application to the transaminase catalyzed synthesis of chiral amino-alcohols ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F47 keywords: nonlinear kinetic modelling, transaminase, reversible bioconversions, amino-alcohols, microscale high-throughput, reaction mechanism selection note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions. abstract: This work describes the establishment of a full kinetic model, including values of apparent kinetic parameters, for the whole cell E. coli mediated synthesis of the chiral amino-alcohol (2S,3R)-2-amino-1,3,4-butanetriol (ABT), using (S)-(-)-α-methylbenzylamine (MBA) as amino donor. The whole cell biocatalyst expressed the CV2025 ω-transaminase from Chromobacterium violaceum. Establishment of the most suitable reaction mechanism and determination of the complete forward and reverse kinetic parameter values for the reversible bioconversion where obtained using a hybrid methodology. This combined traditional initial rate experiments to identify a solution in the vicinity of the global minimum, with nonlinear regression methods to determine the exact location of the solution. The systematic procedure included selection and statistical evaluation of different kinetic models that best described the measured reaction rates and which ultimately provided new insights into the reaction mechanism; in particular the possible formation of a dead end complex between the amino donor and the cofactor enzyme complex. The hybrid methodology was combined with a microscale experimental platform, to significantly reduce both the number of experiments required as well as the time and material required for full kinetic parameter estimation. The equilibrium constant was determined to be 849, and the forward and reverse rate constants were found to be 97 and 13min-1, respectively, which greatly favoured the asymmetric synthesis of chiral ABT. Using the established kinetic model, the asymmetric synthesis of ABT was simulated, and excellent agreement was found between the experimental and predicted data over a range of reaction conditions. A sensitivity analysis combined with various simulations suggested the crucial bottleneck of the reaction was the second half reaction of the ping pong bi-bi mechanism, in part due to the low Michaelis constant of substrate l-erythrulose (ERY). The toxicity of MBA towards the transaminase was identified as another major bottleneck. The kinetic model was useful to give early insights into the most appropriate bioconversion conditions, which can improve the rate and yield of ABT formation, as well as minimizing the toxicity and inhibition effects of the substrates and products. The systematic methodology developed here is considered to be generic and useful in regard to speeding up bioconversion process design and optimization. © 2013 Elsevier B.V. date: 2013-04 date_type: published publisher: ELSEVIER SCIENCE BV official_url: http://dx.doi.org/10.1016/j.bej.2013.01.010 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 871382 doi: 10.1016/j.bej.2013.01.010 lyricists_name: Baganz, Frank lyricists_name: Lye, Gary lyricists_name: Ward, John lyricists_name: Du, Chuanjie lyricists_name: Rios-Solis, Leonardo lyricists_id: FBAGA65 lyricists_id: GJLYE60 lyricists_id: JMWAR05 lyricists_id: CDUXX19 lyricists_id: LRIOS73 actors_name: Rios-Solis, Leonardo actors_id: LRIOS73 actors_role: owner funding_acknowledgements: [Mexican National Council for Science and Technology (CONACYT)]; [Mexican Ministry of Public Education (SEP)]; [Ministry of Higher Education of Malaysia (MOHE)]; [UCL Department of Biochemical Engineering]; GR/S62505/01 [UK Engineering and Physical Sciences Research Council (EPSRC)]; EP/G005834/1 [EPSRC]; EP/G005834/1 [Engineering and Physical Sciences Research Council]; GR/S62505/01 [Engineering and Physical Sciences Research Council] full_text_status: public publication: Biochemical Engineering Journal volume: 73 pagerange: 38-48 pages: 11 citation: Rios-Solis, L; Bayir, N; Halim, M; Du, C; Ward, JM; Baganz, F; Lye, GJ; (2013) Non-linear kinetic modelling of reversible bioconversions: Application to the transaminase catalyzed synthesis of chiral amino-alcohols. Biochemical Engineering Journal , 73 pp. 38-48. 10.1016/j.bej.2013.01.010 <https://doi.org/10.1016/j.bej.2013.01.010>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10194395/3/Rios-Solis_Non-linear%20kinetic%20modelling%20of%20reversible%20bioconversions_AAM.pdf