Chemical changes in bovine serum albumin photoinduced by pterin

Thomas, Andrés H.; Zurbano, Beatriz N.; Lorente, Carolina; Santos, Javier; Román, Ernesto A.; Dántola, M. Laura

doi:10.1016/j.jphotobiol.2014.10.007

Cited by 15 publications

(14 citation statements)

References 33 publications

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“…We have studied the capability of Ptr to photoinduce chemical and structural changes in bovine serum albumin (BSA) and human serum albumin (HSA). The results obtained for both proteins were very similar, as is expected due to the high structural homology between HSA and BSA [39,40]. Air-equilibrated aqueous solutions of albumin (BSA or HSA) and Ptr (pH 6.0, KH 2 PO 4 1 mM) were exposed to UV-A radiation for different periods of time.…”

Section: Photoinduced Chemical Changes In Serum Albuminsupporting

confidence: 67%

“…The decrease of the intensity of the albumin peak was also observed by size-exclusion chromatography coupled with a light scattering detector (SEC-LS) (Figure 2). In the case of BSA, it was demonstrated that dimerization of the protein occurred, but larger products were not investigated [39]. For HSA, the molecular weights of the photoproducts were determined by SEC-LS, and it was found that oligomers with more than 10 HSA molecules were formed (Figure 2) [40].…”

Section: Photoinduced Chemical Changes In Serum Albuminmentioning

confidence: 99%

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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: Photoinduced Chemical Changes In Serum Albuminsupporting

confidence: 67%

Section: Photoinduced Chemical Changes In Serum Albuminmentioning

confidence: 99%

Photosensitization of peptides and proteins by pterin derivatives

et al. 2017

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“…In addition, these endogenous compounds exhibit an absorption in the UVA region of the solar spectrum ( Figure 2), and thus might represent intrinsic photosensitizers of proteins. Indeed, several studies have demonstrated that pterin (Ptr), the parent and unsubstituted compound of oxidized pterins ( Figure 2), is able to photosensitize the cross-linking of free tyrosine (Tyr) [24] and tyrosine residues of peptides [25,26] and proteins [27,28,29] through a photoinduced electron transfer mechanism.…”

Section: Tyr(-h) Oo'-dityrosinementioning

confidence: 99%

A novel synthetic approach to tyrosine dimers based on pterin photosensitization

et al. 2017

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Oxidative damage to proteins leads to a variety of modifications that are markers of pathogenesis. One of the most important modifications is the dityrosine (Tyr2) cross-link, resulting from an oxidative covalent bond between two tyrosines (Tyr). An optimized methodology for preparation of pure Tyr2 is important to investigate in detail its physicochemical properties and reactivity. Pterin (Ptr), the parent and unsubstituted compound of oxidized pterins, is able to photosensitize the cross-linking of free tyrosine (Tyr) and tyrosine residues of peptides and proteins through a photoinduced electron transfer mechanism. We have optimized a simple, one-step photocatalyzed formation of Tyr2, using Ptr as photocatalyst. Our procedure is carried out in aqueous solutions under UV-A radiation for few minutes. The purification of Tyr2 is performed by reverse-phase chromatography. The obtained highly pure solution is used to fully characterize the Tyr2 (exact mass and 1 H, 1 H-1 H COSY; DEPT; HSQC and HMBC NMR experiments) and to deeper study its fluorescence properties.

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“…This combined with the type II photosensitizer properties of the quinones 1 and 2, to generate singlet oxygen, could result in oxidative stress and cell death. Additionally, type I photosensitization via PCET from tyrosine or tryptophan could contribute to protein damage and enzyme inactivation, [104][105][106][107] as a consequence of further transformation of the amino acid radicals via oxidation and/or dimerization reactions. 108…”

Section: A Quenching Of Naphthoquinonesmentioning

confidence: 99%