4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer.

Chen, L. H.; Kenyon, George L.; Curtin, F.; Harayama, Shigeaki; Bembenek, Michael E.; Hajipour, Gholamhossein; Whitman, Christian P.

doi:10.1016/s0021-9258(19)37101-7

Cited by 101 publications

(81 citation statements)

References 31 publications

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“…Most of the enzymes known so far are proteins composed of chains from several dozen to several thousand amino acids [ 90 , 91 ]. These chains fold up to form a complex three-dimensional spatial structure.…”

Section: The Concept Of Enzymes and Enzymatic Extractionmentioning

confidence: 99%

Modern Methods of Pre-Treatment of Plant Material for the Extraction of Bioactive Compounds

et al. 2022

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In this review, recent advances in the methods of pre-treatment of plant material for the extraction of secondary metabolites with high biological activity are presented. The correct preparation of the material for extraction is as important as the selection of the extraction method. This step should prevent the degradation of bioactive compounds as well as the development of fungi and bacteria. Currently, the methods of preparation are expected to modify the particles of the plant material in such a way that will contribute to the release of bioactive compounds loosely bonded to cell wall polymers. This review presents a wide range of methods of preparing plant material, including drying, freeze-drying, convection drying, microwave vacuum drying, enzymatic processes, and fermentation. The influence of the particular methods on the structure of plant material particles, the level of preserved bioactive compounds, and the possibility of their release during the extraction were highlighted. The plant material pre-treatment techniques used were discussed with respect to the amount of compounds released during extraction as well their application in various industries interested in products with a high content of biologically active compounds, such as the pharmaceutical, cosmetics, and food industries.

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Section: The Concept Of Enzymes and Enzymatic Extractionmentioning

confidence: 99%

Modern Methods of Pre-Treatment of Plant Material for the Extraction of Bioactive Compounds

et al. 2022

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“…The structural features of our model enzyme are based roughly on 4-oxalocrotonate tautomerase (4-OT), an enzyme which contains multiple binding sites and catalyzes the isomerization of unsaturated ketones. 20 This enzyme is a hexamer which is composed of three dimers; 21 each monomeric enzyme in a dimer has 62 amino acid residues. The entire hexamer has six active sites where catalytic reactions can take place.…”

Section: Model For the Enzymatic Systemmentioning

confidence: 99%

Diffusional correlations among multiple active sites in a single enzyme

Echeverría

Kapral

2014

Phys. Chem. Chem. Phys.

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Simulations of the enzymatic dynamics of a model enzyme containing multiple substrate binding sites indicate the existence of diffusional correlations in the chemical reactivity of the active sites. A coarse-grain, particle-based, mesoscopic description of the system, comprising the enzyme, the substrate, the product and solvent, is constructed to study these effects. The reactive and non-reactive dynamics is followed using a hybrid scheme that combines molecular dynamics for the enzyme, substrate and product molecules with multiparticle collision dynamics for the solvent. It is found that the reactivity of an individual active site in the multiple-active-site enzyme is reduced substantially, and this effect is analyzed and attributed to diffusive competition for the substrate among the different active sites in the enzyme.

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“…[1][2] In contrast, the use of secondary amines in enzyme catalysis is signi cantly rarer and their scope has not been fully explored. [3][4][5][6][7] However, while the basicity of cyclic secondary amines are similar to their primary counterparts, they are signi cantly more nucleophilic. [8][9][10] Additionally, when a secondary amine reacts with a carbonyl substrate, the resulting iminium ion intermediate does not contain a proton on the nitrogen atom; this can prompt reactions with a latent nucleophile or a base for enamine formation, driving the catalytic cycles forward.…”

Section: Introductionmentioning

confidence: 99%

“…[21][22][23] These protein catalysts could catalyze various types of reactions, including conjugate addition, [19][20][21] aldol condensation, 18,22 transfer hydrogenation 23 and epoxidation. 24 However, since there are only a few proteins that contain a N-terminal proline within their cavity 3,6 and also only a few that bind biotin with signi cant a nity, [25][26] the choice of protein templates for hosting secondary amine is limited. Indeed, the full bene t of using protein as host has not been revealed, and a generic approach that facilitates the incorporation of secondary amine is needed.…”

Section: Introductionmentioning

confidence: 99%

Break the template boundary: Test of different protein scaffolds by genetic code expansion resulted in NADPH-dependent secondary amine catalysis

Williams

Tsai

Luk

2021

Preprint

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Here, incorporation of secondary amine by genetic code expansion was used to expand the potential protein templates for artificial enzyme design. Pyrrolysine analogue containing a D-proline could be stably incorporated into proteins, including the multidrug-binding LmrR and nucleotide-binding dihydrofolate reductase (DHFR). Both modified scaffolds were catalytically active, mediating transfer hydrogenation with a relaxed substrate scope. The protein templates played a distinctive role in that, while the LmrR variants were confined to the biomimetic BNAH as the hydride source, the optimal DHFR variant favorably used the pro-R hydride from NADPH for reactions. Due to the cofactor compatibility, the DHFR secondary amine catalysis could also be coupled to an enzymatic recycling scheme. This work has illustrated the unique advantages of using proteins as hosts, and thus the presented concept is expected to find uses in enabling tailored secondary amine catalysis.

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4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer.

Cited by 101 publications

References 31 publications

Modern Methods of Pre-Treatment of Plant Material for the Extraction of Bioactive Compounds

Modern Methods of Pre-Treatment of Plant Material for the Extraction of Bioactive Compounds

Diffusional correlations among multiple active sites in a single enzyme

Break the template boundary: Test of different protein scaffolds by genetic code expansion resulted in NADPH-dependent secondary amine catalysis

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