Production of pteridines during hematopoiesis and T‐lymphocyte proliferation: Potential participation in the control of cytokine signal transmission

Ziegler, Irmgard

doi:10.1002/med.2610100104

Cited by 53 publications

(38 citation statements)

References 60 publications

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“…Pterins are present in human epidermis given that 5,6,7,8-tetrahydrobiopterin (H 4 Bip) is an essential cofactor for aromatic amino acid hydroxylases [17] and participates in the regulation of melanin biosynthesis [18]. In vitiligo, a skin disorder characterized by a defective protection against UV radiation due to the acquired loss of constitutional pigmentation [19], H 4 Bip metabolism is altered [20].…”

Section: Introductionmentioning

confidence: 99%

Photosensitization of peptides and proteins by pterin derivatives

et al. 2017

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Proteins are one of the preferential targets of the photosensitized damaging effects of ultraviolet (UV) radiation on biological system. Pterins belong to a family of heterocyclic compounds, which are widespread in living systems and participate in relevant biological functions. In pathological conditions, such as vitiligo, oxidized pterins accumulate in the white skin patches of patients suffering this depigmentation disorder. It is known that pterins are able to photosensitize damage in nucleotides and DNA by type I (electron transfer) and type II (singlet oxygen) mechanisms. Recently, it has been demonstrated that proteins and its components may also be damaged when solutions containing both proteins and pterin are exposed to UV-A radiation. Therefore, given the biological and medical relevance of the photosensitizing properties of these molecules, we present in this article an overview of the capability of different pterin derivatives to photoinduce damage in proteins present in the skin, focusing our attention on the chemical modifications of tyrosine and tryptophan residues.

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Section: Introductionmentioning

confidence: 99%

Photosensitization of peptides and proteins by pterin derivatives

et al. 2017

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“…In addition, nitric oxide synthase requires 6BH 4 for activity. To date, there is accumulating evidence that pterins are also synthesised during activation of cell-mediated immunity [5]. 6BH 4 is synthesised de novo from guanosine triphosphate (GTP) via the rate-limiting enzyme GTP-cyclohydrolase I.…”

Section: What Are Pterins?mentioning

confidence: 99%

“…One of the most important pterins is (6R)-L-erythro- 5,6,7, which is the essential cofactor for various intracellular metabolic steps including the hydroxylation of the amino acids L-phenylalanine, L-tyrosine and L-tryptophan. In addition, nitric oxide synthase requires 6BH 4 for activity.…”

Section: What Are Pterins?mentioning

confidence: 99%

Successful Treatment of Oxidative Stress in Vitiligo

Schallreuter¹

1999

Skin Pharmacol Physiol

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Patients with vitiligo have low catalase levels in their involved and uninvolved epidermis in association with high levels of hydrogen peroxide (H₂O₂). H₂O₂ has been confirmed for the first time in vivo using Fourier Transform Raman spectroscopy. A topical substitution with a UVB-activated pseudocatalase can successfully remove epidermal H₂O₂ in vitiligo. This approach leads to recovery of the oxidative damage in the epidermis and remarkable repigmentation in this disorder.

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“…In vertebrates and insects (5), compound 4 is the biosynthetic precursor of tetrahydrobiopterin, which is involved in the formation of catecholamines and nitric oxide (6,7). Tetrahydrobiopterin is also involved in the stimulation of T lymphocytes, although the details are still incompletely understood (8).…”

mentioning

confidence: 99%

Active site topology and reaction mechanism of GTP cyclohydrolase I.

Nar

Huber

Auerbach

et al. 1995

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

119

127

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(5), compound 4 is the biosynthetic precursor of tetrahydrobiopterin, which is involved in the formation of catecholamines and nitric oxide (6, 7). Tetrahydrobiopterin is also involved in the stimulation of T lymphocytes, although the details are still incompletely understood (8).CYH was originally detected in bacteria (9). More recently, the primary structure of CYH from a wide variety of organisms has been determined (10-16). The evolution of the protein has been relatively conservative. Thus, the C-terminal 120 residues of Escherichia coli and human enzymes are 60% identical. The crystal structure of E. coli CYH has recently been solved by single isomorphous replacement and averaging techniquesThe publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. (17). The knowledge of the crystal packing arrangement obtained by electron microscopy (18, 19) was helpful in the initial stages of structure determination. The enzyme complex, a decamer consisting of a pentamer of tightly associated dimers, is doughnut shaped with dimensions of 65 x 100 A.One CYH subunit folds into a a+f structure with a predominantly helical N terminus (Fig. 2). The N-terminal helix hl (residues 5-18) is followed by a helix pair, composed of helix h2 (residues 32-49) and helix h3 (residues 62-72), which are remote from the compact C-terminal domain of the molecule (residues 95-217). This domain has a central fourstranded antiparallel 13-sheet that is flanked on both sides by a-helices. The folding topology of this domain is identical to that of a subunit of the second enzyme in tetrahydrobiopterin biosynthesis pathway, 6-pyruvoyltetrahydropterin synthase (20).The association of two CYH monomers to dimers is driven by the formation of a four-helix bundle by helices h2 and h3 of each monomer. Apart from a large hydrophobic surface buried by this interaction, numerous hydrogen bonds and salt bridges serve to stabilize the dimer. The decamer is formed by a fivefold symmetric arrangement of the dimers. Its most striking structural feature is an unprecedented 20-stranded antiparallel ,B-barrel (Fig. 2). This paper describes the crystal structure of a complex of CYH with dGTP, the substrate analog.** By using the inforAbbreviation: CYH, GTP cyclohydrolase I.

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Production of pteridines during hematopoiesis and T‐lymphocyte proliferation: Potential participation in the control of cytokine signal transmission

Cited by 53 publications

References 60 publications

Photosensitization of peptides and proteins by pterin derivatives

Photosensitization of peptides and proteins by pterin derivatives

Successful Treatment of Oxidative Stress in Vitiligo

Active site topology and reaction mechanism of GTP cyclohydrolase I.

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