Long-range electron transfer between tyrosine and tryptophan in peptides

Faraggi, M.; DeFelippis, Michael R.; Klapper, Michael H.

doi:10.1021/ja00196a019

Cited by 131 publications

(90 citation statements)

References 1 publication

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“…34), forming the neutral tyrosyl radical TyrO ⅐ . The spectral features of the 50-s phase are very similar to those observed for the reaction Trp ⅐ ⅐⅐⅐TyrOH 3 TrpH⅐⅐⅐TyrO ⅐ in model peptides (12,15,16). We considered alternative assignments for the species, which is oxidized by the tryptophanyl radical during the 50-s phase.…”

Section: Resultsmentioning

confidence: 72%

“…Prominent examples include a catalytically essential tyrosyl radical in ribonucleotide reductase (3,4), tyrosine Y Z in photosynthetic wateroxidizing enzyme (5)(6)(7), and a tryptophan that can be oxidized by a photoexcited flavin semiquinone in DNA photolyase (PL) from Escherichia coli (8)(9)(10). It has even been suggested that tryptophan and tyrosine could act as sequential redox components in long-range electron transfer in proteins (11)(12)(13). The feasibility of such an electron transfer has been demonstrated in aqueous amino acids solutions (14), in model peptides (12,15,16), and in proteins after artificial oxidation of tryptophan (11,17), but it has never been demonstrated in a native biological reaction.…”

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confidence: 99%

“…It has even been suggested that tryptophan and tyrosine could act as sequential redox components in long-range electron transfer in proteins (11)(12)(13). The feasibility of such an electron transfer has been demonstrated in aqueous amino acids solutions (14), in model peptides (12,15,16), and in proteins after artificial oxidation of tryptophan (11,17), but it has never been demonstrated in a native biological reaction.…”

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Intraprotein electron transfer between tyrosine and tryptophan in DNA photolyase from Anacystis nidulans

Aubert

Mathis²,

Eker³

et al. 1999

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

135

122

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Light-induced electron transfer reactions leading to the fully reduced, catalytically competent state of the f lavin adenine dinucleotide (FAD) cofactor have been studied by f lash absorption spectroscopy in DNA photolyase from Anacystis nidulans. The protein, overproduced in Escherichia coli, was devoid of the antenna cofactor, and the FAD chromophore was present in the semireduced form, FADH ⅐ , which is inactive for DNA repair. We show that after selective excitation of FADH ⅐ by a 7-ns laser f lash, fully reduced FAD (FADH ؊ ) is formed in less than 500 ns by electron abstraction from a tryptophan residue. Subsequently, a tyrosine residue is oxidized by the tryptophanyl radical with t1 ͞2 ‫؍‬ 50 s. The amino acid radicals were identified by their characteristic absorption spectra, with maxima at 520 nm for Trp ⅐ and 410 nm for TyrO ⅐ . The newly discovered electron transfer between tyrosine and tryptophan occurred for Ϸ40% of the tryptophanyl radicals, whereas 60% decayed by charge recombination with FADH ؊ (t1 ͞2 ‫؍‬ 1 ms). The tyrosyl radical can also recombine with FADH ؊ but at a much slower rate (t1 ͞2 ‫؍‬ 76 ms) than Trp ⅐ . In the presence of an external electron donor, however, TyrO ⅐ is rereduced efficiently in a bimolecular reaction that leaves FAD in the fully reduced state FADH ؊ . These results show that electron transfer from tyrosine to Trp ⅐ is an essential step in the process leading to the active form of photolyase. They provide direct evidence that electron transfer between tyrosine and tryptophan occurs in a native biological reaction.The role of amino acid radicals as intermediates in electron and hydrogen atom transfer is a topic of growing interest and research activity in enzymology (1, 2). Prominent examples include a catalytically essential tyrosyl radical in ribonucleotide reductase (3, 4), tyrosine Y Z in photosynthetic wateroxidizing enzyme (5-7), and a tryptophan that can be oxidized by a photoexcited flavin semiquinone in DNA photolyase (PL) from Escherichia coli (8-10). It has even been suggested that tryptophan and tyrosine could act as sequential redox components in long-range electron transfer in proteins (11-13). The feasibility of such an electron transfer has been demonstrated in aqueous amino acids solutions (14), in model peptides (12,15,16), and in proteins after artificial oxidation of tryptophan (11, 17), but it has never been demonstrated in a native biological reaction. DNA PLs use blue or near-UV light to repair UV-induced DNA lesions [refs. 18 and 19; either cyclobutane pyrimidine dimers or (6-4) photoproducts] in a variety of organisms, ranging from bacteria to multicellular eukaryotes (reviewed in ref. 20). This enzyme is a single polypeptide of 50-65 kDa. It contains a flavin adenine dinucleotide (FAD) as the essential catalytic cofactor and a second chromophore (either a reduced folate or a 8-OH-5-deazaflavin), which has the sole function of absorbing light and transferring excitation energy to the FAD cofactor (21). The FAD cofactor must be in the ...

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Section: Resultsmentioning

confidence: 72%

mentioning

confidence: 99%

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confidence: 99%

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Intraprotein electron transfer between tyrosine and tryptophan in DNA photolyase from Anacystis nidulans

Aubert

Mathis²,

Eker³

et al. 1999

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

135

122

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“…The former group includes the direct attack by a hydroxyl radical on glutamate residues, which converts the amino acid into pyruvic acid and ammonia or a reaction of the hydroxyl radical with a proline residue, forming aminobutyric acid and carbon dioxide (CO 2 ). Also included in this category are the initial amino-acid side-chain modifications such as aldehyde production, which transfers the radical to the protein backbone via alkoxyl radicals (62,77,118,119,199,202,221,312). Meanwhile, the latter includes direct oxidation of the amino-acid side chains as well as lipid and sugar oxidation by-products that form adducts with the side chains.…”

Section: Fig 1 Interaction Of Proteome With Reactive Nitrogen Oxygementioning

confidence: 99%

Cardiovascular Redox and Ox Stress Proteomics

Kumar

Calamaras

Haeussler

et al. 2012

Antioxidants & Redox Signaling

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Significance: Oxidative post-translational modifications (OPTMs) have been demonstrated as contributing to cardiovascular physiology and pathophysiology. These modifications have been identified using antibodies as well as advanced proteomic methods, and the functional importance of each is beginning to be understood using transgenic and gene deletion animal models. Given that OPTMs are involved in cardiovascular pathology, the use of these modifications as biomarkers and predictors of disease has significant therapeutic potential. Adequate understanding of the chemistry of the OPTMs is necessary to determine what may occur in vivo and which modifications would best serve as biomarkers. Recent Advances: By using mass spectrometry, advanced labeling techniques, and antibody identification, OPTMs have become accessible to a larger proportion of the scientific community. Advancements in instrumentation, database search algorithms, and processing speed have allowed MS to fully expand on the proteome of OPTMs. In addition, the role of enzymatically reversible OPTMs has been further clarified in preclinical models. Critical Issues: The identification of OPTMs suffers from limitations in analytic detection based on the methodology, instrumentation, sample complexity, and bioinformatics. Currently, each type of OPTM requires a specific strategy for identification, and generalized approaches result in an incomplete assessment. Future Directions: Novel types of highly sensitive MS instrumentation that allow for improved separation and detection of modified proteins and peptides have been crucial in the discovery of OPTMs and biomarkers. To further advance the identification of relevant OPTMs in advanced search algorithms, standardized methods for sample processing and depository of MS data will be required. Antioxid. Redox Signal. 17, 1528-1559.

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“…The electron transfer within a protein v/a the intramolecular charge transfer between the aromatic rings of tyrosine and tryptophan residues is of importance in biological oxidation-reduction systems (Ghiron, Bazin & Santus, 1986;Faraggi, DeFelippis & Klapper, 1989). As part of a structural study on the indole-phenol ring interactions at the atomic level (Ishida & Inoue, 1981), the crystal structure of the title compound was analysed.…”

Section: (I)mentioning

confidence: 99%