Photolysis (λ = 254 nm) of phenylalanine in aqueous solution

Jin, Faming; Leitich, Johannes; Sonntag, Clemens von

doi:10.1016/1010-6030(94)03895-2

Cited by 5 publications

(4 citation statements)

References 26 publications

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“…The presence of O 2 has only a minor effect on the photolytic decay of Phe, which is in contrast with the behavior of Tyr, − for which O 2 largely enhances its photoreactivity. This difference is attributed to the higher quantum yield for the triplet of Tyr relative to Phe (ϕ T, Tyr = 0.50, ϕ T, Phe = 0.40) both determined upon excitation at 266 nm .…”

Section: Resultsmentioning

confidence: 93%

“…39,40 These products can be explained through photoionization of Phe to form the corresponding radical cation, 34 that reacts with water to produce hydrocyclohexadienyl radicals, which further react with O 2 to yield the corresponding hydroxylated tyrosines. 35 3.3. Photoinsertion of Phenylalanine onto Modified NTO.…”

Section: Resultsmentioning

confidence: 99%

“…The amino group was retained, and a molecule of water incorporated. In the presence of O 2 the triplet state was readily quenched and different ring-hydroxylated tyrosines (o, m, p) produced. , These products can be explained through photoionization of Phe to form the corresponding radical cation, that reacts with water to produce hydrocyclohexadienyl radicals, which further react with O 2 to yield the corresponding hydroxylated tyrosines …”

Section: Resultsmentioning

confidence: 99%

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Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Humeres¹,

Souza²,

Debacher³

et al. 2014

Langmuir

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Photolyses at 254 nm of phenylalanine (Phe) in aqueous solutions, were carried out in the presence of oxidized carbon nanotubes modified by the reaction with SO2 (mNTO). Kinetics of the photolyses were followed by UV spectrophotometry at 220 nm, and the products were characterized by HPLC, XPS, and (13)C-SSNMR. The ratio of the initial rates of photolysis in the presence and absence of mNTO, k*/ko*, showed a systematic decrease. The photolytic decay of Phe occurs with minor formation of tyrosine. The mass of nanotubes produced an exponential attenuation of the photolytic decomposition of Phe. Total carbon analyses (TCA) showed no inorganic carbon formation after the photolyses. The first-order rate constant of photofunctionalization of mNTO by the insertion of phenylalanine onto the nanotube matrix was calculated from TCA to be kin = 30.1 min(-1). Comparison of the XPS spectra of the mNTO before and after the photolysis, using the atom inventory technique, suggests the insertion of Phe along with the extrusion of a sulfide radical anion ((•)S(-)) which undergo subsequent oxidation to SO4(2-). The obtained results show the effects of mNTO on the photolysis of Phe and provide a new method of photofunctionalization of carbon materials, modified by the intermediates of the reduction of SO2, with an organic moiety.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Humeres¹,

Souza²,

Debacher³

et al. 2014

Langmuir

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“…Only the aromatic side chains of tyrosine, phenylalanine, and tryptophan absorb UV 254 irradiation (ε 254 = 350, 140, and 2900 M −l cm −l , respectively) as do disulfide cystines (ε 254 = 270 M −l cm −l ) . These residues have been shown to degrade with UV 254 when in free amino acid − , in short peptide , and in full protein form , , and UV 254 irradiation lead to protein cleavage in at least one report . UV 254 absorbing residues may also act as sensitizers that produce ROS and subsequently oxidize nonabsorbing residues , .…”

Section: Introductionmentioning

confidence: 99%

Oxidation of Virus Proteins during UV₂₅₄ and Singlet Oxygen Mediated Inactivation

Wigginton

Menin

Montoya

et al. 2010

Environ. Sci. Technol.

100

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Despite the widespread use of UV(254) irradiation and solar disinfection for water treatment, little is known about the photochemical pathways that lead to virus inactivation by these treatments. The goal of this study was to identify reactions that occur in virus capsid proteins upon treatment by UV(254) irradiation and (1)O(2), an important oxidant involved in sunlight-mediated disinfection. Bacteriophage MS2 was inactivated via UV(254) irradiation and exposure to (1)O(2) in buffered water, and their capsid proteins were then analyzed with MALDI-TOF-TOF and ESI-TOF before and after digestion with protease enzymes. The results demonstrate that chemical modifications occur in the MS2 major capsid protein with both treatments. One oxidation event was detected following (1)O(2) treatment in an amino acid residue located on the capsid outer surface. UV(254) treatment caused three chemical reactions in the capsid proteins, two of which were oxidation reactions with residues on the capsid outer surface. A site-specific cleavage also occurred with UV(254) irradiation at a protein chain location on the inside face of the capsid shell. We attribute this UV(254) induced protein scission, which is nearly unprecedented in the literature, to a close association between the affected residues and viral RNA, an efficient UV(254) absorber. These results suggest that viral protein oxidation by UV(254) and (1)O(2) may play a role in virus inactivation and that viral inactivation may be tracked with mass spectrometric measurements.

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Nucleobases, Nucleosides and Nucleotides

2006

Free-Radical-Induced DNA Damage and Its Repair

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Photolysis (λ = 254 nm) of phenylalanine in aqueous solution

Cited by 5 publications

References 26 publications

Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Oxidation of Virus Proteins during UV₂₅₄ and Singlet Oxygen Mediated Inactivation

Nucleobases, Nucleosides and Nucleotides

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Photolysis (λ = 254 nm) of phenylalanine in aqueous solution

Cited by 5 publications

References 26 publications

Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Photolysis of Phenylalanine in the Presence of Oxidized Carbon Nanotubes

Oxidation of Virus Proteins during UV254 and Singlet Oxygen Mediated Inactivation

Nucleobases, Nucleosides and Nucleotides

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Product

Resources

About

Oxidation of Virus Proteins during UV₂₅₄ and Singlet Oxygen Mediated Inactivation