Water in enzyme reactions: biophysical aspects of hydration-dehydration processes

Pocker, Y.

doi:10.1007/pl00000741

Cited by 59 publications

(45 citation statements)

References 96 publications

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“…[23] In low-water-content media, the relationships between the solvation process and the enzyme kinetics have been reported, [24] with the hydration of the active site of the enzyme playing a critical role in substrate recognition and transformation. [25] Water molecules can interact with the protein surface and occupy internal cavities and deep clefts, which optimizes spatial configurations and minimizes energetic pathways.…”

Section: Optimization Of Water Requirement For Oxidation In An Organimentioning

confidence: 98%

A Novel Synthesis of Bioactive Catechols by Layer‐by‐Layer Immobilized Tyrosinase in an Organic Solvent Medium

et al. 2011

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Commercial and extracted mushroom tyrosinases were supported on Eupergit C 250 L and protected by a coating of oppositely charged polyelectrolytes by means of the layer‐by‐layer technique. The kinetic parameters (Km, Vmax, and Vmax/Km) of these novel biocatalysts in both organic and aqueous media were evaluated, showing tyrosinase to be more reactive in organic solvent than in buffer solution. Heterogeneous tyrosinase systems were used for the oxidation of a large group of phenol derivatives to the corresponding catechols. Different enzyme reactivities were found depending on the substrate structure. The catalyst activity was retained for successive runs. Catechols are difficult to synthesize through traditional chemical methods under environmentally friendly conditions; the use of immobilized tyrosinase opens a novel synthetic alternative to this interesting biologically active family of substances.

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Section: Optimization Of Water Requirement For Oxidation In An Organimentioning

confidence: 98%

A Novel Synthesis of Bioactive Catechols by Layer‐by‐Layer Immobilized Tyrosinase in an Organic Solvent Medium

et al. 2011

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“…In enzymes, for example, hydration enhances enzymatic rates, and non-catalytic water molecules can aid in transporting substrates and protons into the catalytic sites [1,8,9]. Numerous experiments have suggested that a minimum hydration level of h~0.2 (g water/g protein) is required for enzymes to function [1,[10][11][12].…”

Section: Main Textmentioning

confidence: 99%

Dynamical Transition of Collective Motions in Dry Proteins

et al. 2017

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“…function-site solvation | ultrafast dynamics | spectral tuning | protein rigidity and flexibility | femtosecond-resolved emission spectra D ynamic solvation in binding and active sites plays a critical role in protein recognition and enzyme reaction, and such local motions optimize spatial configurations and minimize energetic pathways (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). These dynamics involve local constrained protein and trapped-water motions within angstrom distance and occur on ultrafast time scales (6,7,10,11).…”

mentioning

confidence: 99%

Ultrafast solvation dynamics at binding and active sites of photolyases

Chang

Guo

Kao

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Dynamic solvation at binding and active sites is critical to protein recognition and enzyme catalysis. We report here the complete characterization of ultrafast solvation dynamics at the recognition site of photoantenna molecule and at the active site of cofactor/ substrate in enzyme photolyase by examining femtosecondresolved fluorescence dynamics and the entire emission spectra. With direct use of intrinsic antenna and cofactor chromophores, we observed the local environment relaxation on the time scales from a few picoseconds to nearly a nanosecond. Unlike conventional solvation where the Stokes shift is apparent, we observed obvious spectral shape changes with the minor, small, and large spectral shifts in three function sites. These emission profile changes directly reflect the modulation of chromophore's excited states by locally constrained protein and trapped-water collective motions. Such heterogeneous dynamics continuously tune local configurations to optimize photolyase's function through resonance energy transfer from the antenna to the cofactor for energy efficiency and then electron transfer between the cofactor and the substrate for repair of damaged DNA. Such unusual solvation and synergetic dynamics should be general in function sites of proteins.function-site solvation | ultrafast dynamics | spectral tuning | protein rigidity and flexibility | femtosecond-resolved emission spectra D ynamic solvation in binding and active sites plays a critical role in protein recognition and enzyme reaction, and such local motions optimize spatial configurations and minimize energetic pathways (1-11). These dynamics involve local constrained protein and trapped-water motions within angstrom distance and occur on ultrafast time scales (6,7,10,11). Typically, extrinsic dye molecules or synthetic amino acids were used as local optical probes to label function sites, and the local relaxations were observed, ranging from femtoseconds to nanoseconds (5,(12)(13)(14). Such labeling of bulky dye molecules usually induces significant local perturbations, and direct characterization with intrinsic chromophores in proteins eliminates those interferences and reveals intact environment responses (4, 7, 15-21), as recently examined in green fluorescence proteins (21). We have recently studied a series of flavoproteins using intrinsic flavin molecule as the optical probe (10, 22, 23) and especially found the important functional role of local solvation in photolyase (10).Photolyase, a flavoprotein and a photoenzyme, repairs damaged DNA caused by UV irradiation. Two types of structurally similar photolyases are specific for two major UV-induced DNA lesions of cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct (24). The CPD photolyase contains two noncovalently bound chromophores, a pterin molecule in the form of methenyltetrahydrofolate (MTHF) in the binding site as the photoantenna for energy efficiency and a fully reduced flavin adenine dinucleotide (FADH − ) at the active site as the catalytic cofactor for repair of d...

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Water in enzyme reactions: biophysical aspects of hydration-dehydration processes

Cited by 59 publications

References 96 publications

A Novel Synthesis of Bioactive Catechols by Layer‐by‐Layer Immobilized Tyrosinase in an Organic Solvent Medium

A Novel Synthesis of Bioactive Catechols by Layer‐by‐Layer Immobilized Tyrosinase in an Organic Solvent Medium

Dynamical Transition of Collective Motions in Dry Proteins

Ultrafast solvation dynamics at binding and active sites of photolyases

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