Advances in Kinetic Isotope Effect Measurement Techniques for Enzyme Mechanism Study

Gu, Hong; Zhang, Shuming

doi:10.3390/molecules18089278

Cited by 18 publications

(17 citation statements)

References 54 publications

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“…Thus taking into account the numerous data on the KIE of pharmaceutical substances in waters with different D/H ratios, it can be predicted that deuterium will become a medico-chemical instrument [ 59 ].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

et al. 2021

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The most important task in the design of dosage forms is to modify the pharmaceutical substances structure in order to increase solubilization, targeted delivery, controlled rate of drug administration, and its bioavailability. Screening—laboratory (in vitro) or computer (in silico)—as a procedure for selecting a prototype for the design of a drug molecule, involves several years of research and significant costs. Among a large number of solvents and diluents (alcohol, ether, oils, glycerol, Vaseline) used in the pharmaceutical industry for the manufacture of drugs water finds the greatest application. This is because all biological reactions (reactions in living systems) take place in water and distribution of the fluid in the body and the substances found within is critical for the maintenance of intracellular and extracellular functions. Modern studies in the field of the stable isotopic compositions of natural water and its structure and properties make it possible to use isotopic transformations of the water to improve the pharmacokinetic properties of medicinal substances without previous structural modification. It is known that by replacing any of the atoms in the reacting substance molecule with its isotope, it is possible to record changes in the reactivity, which are expressed as a change in the reaction rate constant, i.e., in the manifestation of the kinetic isotope effect (KIE). The article presents the results of studies on the effect of the kinetic isotope effect of a solvent—water—on increasing the solubility and dissolution rate constants of poorly soluble drugs using laser diffraction spectroscopy. The results of the studies can be successfully implemented in pharmaceutical practice to overcome the poor solubility of medicinal substances of classes II and IV, according to the biopharmaceutical classification system (BCS), in water for pharmaceutical purposes by performing its preliminary and safe isotopic modification.

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Section: Discussionmentioning

confidence: 99%

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

et al. 2021

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“…40,41 Primary KIEs occur when a bond is formed or broken to the isotopic atom during the reaction while secondary KIEs are observed when the number of bonds to the isotopic atom remains unchanged. 42 The direct comparison, equilibrium perturbation and the internal competition method are the three main methods for the measurement of KIEs. 43 Several methods, including liquid scintillation counting, mass spectrometry, nuclear magnetic resonance spectroscopy and polarimetry have been used to determine KIEs.…”

Section: Enzyme Transition Statesmentioning

confidence: 99%

The transition to magic bullets – transition state analogue drug design

2018

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“…Isotope effects on physical and chemical properties have been investigated for various proteins. Consequently, the properties and reactivities of many deuterated proteins have been shown to differ from those of their protiated counterparts (Hattori et al, 1965;Chen et al, 1984;Brockwell et al, 2001;Cioni & Stambini, 2002;Cleland, 2005;Schramm, 2007;Piszczek et al, 2011;Gu & Zhang, 2013).…”

Section: Introductionmentioning

confidence: 99%

X-ray crystallographic studies on the hydrogen isotope effects of green fluorescent protein at sub-ångström resolutions

Tai

Takaba

Hanazono

et al. 2019

Acta Cryst Sect D Struct Biol

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PDB references: S65T/F99S/M153T/V163A variant of green fluorescent protein, perdeuterated, pD 8.5, 6kkz; perdeuterated, pD 7.0, 6kl0; nondeuterated, pD 8.5, 6kl1Supporting information: this article has supporting information at journals.iucr.org/dHydrogen atoms are critical to the nature and properties of proteins, and thus deuteration has the potential to influence protein function. In fact, it has been reported that some deuterated proteins show different physical and chemical properties to their protiated counterparts. Consequently, it is important to investigate protonation states around the active site when using deuterated proteins. Here, hydrogen isotope effects on the S65T/F99S/M153T/V163A variant of green fluorescent protein (GFP), in which the deprotonated B form is dominant at pH 8.5, were investigated. The pH/pD dependence of the absorption and fluorescence spectra indicates that the protonation state of the chromophore is the same in protiated GFP in H 2 O and protiated GFP in D 2 O at pH/pD 8.5, while the pK a of the chromophore became higher in D 2 O. Indeed, X-ray crystallographic analyses at sub-å ngströ m resolution revealed no apparent changes in the protonation state of the chromophore between the two samples. However, detailed comparisons of the hydrogen OMIT maps revealed that the protonation state of His148 in the vicinity of the chromophore differed between the two samples. This indicates that protonation states around the active site should be carefully adjusted to be the same as those of the protiated protein when neutron crystallographic analyses of proteins are performed.

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Advances in Kinetic Isotope Effect Measurement Techniques for Enzyme Mechanism Study

Cited by 18 publications

References 54 publications

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

Evaluation of Poorly Soluble Drugs’ Dissolution Rate by Laser Scattering in Different Water Isotopologues

The transition to magic bullets – transition state analogue drug design

X-ray crystallographic studies on the hydrogen isotope effects of green fluorescent protein at sub-ångström resolutions

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