Acidity of carboxyl group of tyrosine and its analogues and derivatives studied by steady-state fluorescence spectroscopy

Szabelski, Mariusz; Guzow, Katarzyna; Rzeska, Alicja; Malicka, Joanna; Przyborowska, Monika; Wiczk, Wiesław

doi:10.1016/s1010-6030(02)00187-9

Cited by 26 publications

(12 citation statements)

References 24 publications

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“…To check this hypothesis, triplet quenching of (R)-and (S)-SUP by Trp-Tyr was performed at pH 2.3; under these conditions, where the amount of zwitterion is strongly decreased, no stereodifferentiation was detected (data not shown). Moreover, when N-Boc-(S)-Tyr was used as quencher, (at pH 3.4 close to its pK a ) [20] chiral recognition (measured as Tyr(-H)C formation) was also observed, although to a lower degree. Finally, no chiral recognition was observed when N-Boc-(S)-Tyr methyl ester was used as quencher at pH 3.8.…”

mentioning

confidence: 98%

Intramolecular Electron Transfer between Tyrosine and Tryptophan Photosensitized by a Chiral π,π* Aromatic Ketone

Galian

Pastor‐Pérez

Miranda

et al. 2005

Chemistry A European J

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The photochemical reaction of Trp and Tyr and related peptides with Suprofen (SUP) as sensitizer in H2O/CH3CN (28:1 v/v) solutions has been studied by time-resolved spectroscopy. The results show that SUP induces oxidation of both Trp and Tyr, as well as intramolecular-ET reactions in the related peptides. The influence of photosensitizer configuration on the involved processes has been studied by using the enantiomerically pure compounds. A significant chiral recognition is observed in which the concentration of the radicals formed after triplet quenching depends on the configuration of the chiral center; the quenching process is higher when using the (R)-SUP enantiomer.

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mentioning

confidence: 98%

Intramolecular Electron Transfer between Tyrosine and Tryptophan Photosensitized by a Chiral π,π* Aromatic Ketone

Galian

Pastor‐Pérez

Miranda

et al. 2005

Chemistry A European J

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“…The pK 1 and pK 2 values in the ground state were computed by using Origin 6.0 program, based on absorbance variations at a selected wavelength and by using non-linear least squares method according to the equation described in [42]. Kinetic measurements were carried out using a stopped-flow technique and an Applied Photophysics SX-17MV spectrophotometer.…”

Section: Methodsmentioning

confidence: 99%

Coordinate cis-[Cr(C2O4)(pm)(OH2)2]+ Cation as Molecular Biosensor of Pyruvate’s Protective Activity Against Hydrogen Peroxide Mediated Cytotoxity

Jacewicz

Szkatuła

Chylewska

et al. 2008

Sensors

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In this paper instrumental methods of carbon dioxide (CO2) detection in biological material were compared. Using cis-[Cr(C2O4)(pm)(OH2)2]+ cation as a specific molecular biosensor and the stopped-flow technique the concentrations of CO2 released from the cell culture medium as one of final products of pyruvate decomposition caused by hydrogen peroxide were determined. To prove the usefulness of our method of CO2 assessment in the case of biological samples we investigated protective properties of exogenous pyruvate in cultured osteosarcoma 143B cells exposed to 1 mM hydrogen peroxide (H2O2) added directly to culture medium. Pyruvic acid is well known scavenger of H2O2 and, moreover, a molecule which is recognized as one of the major mediator of oxidative stress detected in many diseases and pathological situations like ischemia-reperfusion states. The pyruvate's antioxidant activity is described as its rapid reaction with H2O2, which causes nonenzymatic decarboxylation of pyruvate and releases of CO2, water and acetate as final products. In this work for the first time we have correlated the concentration of CO2 dissolved in culture medium with pyruvate's oxidant-scavenging abilities. Moreover, the kinetics of the reaction between aqueous solution of CO2 and coordinate ion, cis-[Cr(C2O4)(pm)(OH2)2]+ was analysed. The results obtained enabled determination of the number of steps of the reaction studied. Based on the kinetic equations, rate constants were determined for each step.

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“…The pK values for the acid dissociation of cis-[Cr(phen) 2 (OH 2 ) 2 ] 3+ were determined spectrophotometrically over the 340 Ä 700 nm range, where this species has an extinction coefficient of 36.3 M )1 cm )1 . Then the pK 1 and pK 2 values in the ground state were computed using the Origin 6.0 program, based on absorbance variations at a selected wavelength, and by using the non-linear least squares method according to Equation (1) [16]:…”

Section: Determination Of Acid-dissociation Constantsmentioning

confidence: 99%

A Stopped-flow Study on the Kinetics and Mechanism of CO2 Uptake by the cis-[Cr(1,10-phenanthroline)2(OH2)2]3+ Complex Ion

Jacewicz

Łapińska

Dąbrowska

et al. 2006

Transition Met Chem

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Acidity of carboxyl group of tyrosine and its analogues and derivatives studied by steady-state fluorescence spectroscopy

Cited by 26 publications

References 24 publications

Intramolecular Electron Transfer between Tyrosine and Tryptophan Photosensitized by a Chiral π,π* Aromatic Ketone

Intramolecular Electron Transfer between Tyrosine and Tryptophan Photosensitized by a Chiral π,π* Aromatic Ketone

Coordinate cis-[Cr(C2O4)(pm)(OH2)2]+ Cation as Molecular Biosensor of Pyruvate’s Protective Activity Against Hydrogen Peroxide Mediated Cytotoxity

A Stopped-flow Study on the Kinetics and Mechanism of CO2 Uptake by the cis-[Cr(1,10-phenanthroline)2(OH2)2]3+ Complex Ion

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