Browsing by Author "Davies, Michael J."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- ItemAggregation of alpha- and beta- caseins induced by peroxyl radicals involves secondary reactions of carbonyl compounds as well as di-tyrosine and di-tryptophan formation(2018) Fuentes Lemus, Eduardo Felipe; Silva, Eduardo; Barrias, Pablo; Aspee, Alexis; Escobar Álvarez, Elizabeth; Lorentzen, Lasse G.; Carroll, Luke; Leinisch, Fabian; Davies, Michael J.; López Alarcón, Camilo Ignacio
- ItemBinding of rose bengal to lysozyme modulates photooxidation and cross-linking reactions involving tyrosine and tryptophan(2019) Fuentes Lemus, Eduardo Felipe; Mariotti, Michele; Hägglund, Per; Leinisch, Fabian; Fierro Huerta, Angélica; Silva, Eduardo; López Alarcón, Camilo Ignacio; Davies, Michael J.
- ItemChemical Modification of Lysozyme, Glucose 6-Phosphate Dehydrogenase, and Bovine Eye Lens Proteins Induced by Peroxyl Radicals : Role of Oxidizable Amino Acid Residues(2013) Arenas, Andrea; López Alarcón, Camilo Ignacio; Kogan Bocian, Marcelo; Lissi Gervaso, Eduardo A.; Davies, Michael J.; Silva Stevens, Eduardo Andrés
- ItemComplexation of AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride) with cucurbit[7]uril enhances the yield of AAPH-derived radicals(2023) Forero Girón, Angie; Fuentealba Patiño, Denis Alberto; Mariño Ocampo, Nory Johana; Gutiérrez Oliva, Soledad; Herrera Pisani, Bárbara Andrea; Toro Labbé, Alejandro; Fuentes Lemus, Eduardo; Davies, Michael J.; Aliaga Miranda, Margarita Elly; López Alarcón, Camilo IgnacioAAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride), a water-soluble azo compound is widely employed to produce peroxyl radicals for chemical and biological studies. This compound is shown herein to form a stable inclusion complex with cucurbit[7]uril (CB7), a well-established supramolecular host. Competitive binding assays using berberine dye, isothermal titration calorimetry (ITC), and nuclear magnetic resonance (1H-NMR) experiments, provided evidence for the inclusion of AAPH inside the CB7 cavity with a binding constant of 2.5 ± 0.8 x 105 L mol-1 (determined by ITC). Computational analysis at B3LYP-D3BJ/6-311G(d,p) of the complex (AAPH@CB7) showed interactions of the positively-charged amino groups of AAPH with carbonyl functions at the CB7 entrances. Photolysis of AAPH@CB7 by illumination at 365 nm, gave a higher yield of carbon-centered radicals when compared to the absence of CB7, as evidenced by electron paramagnetic resonance spin trapping using α-phenyl-N-t-butylnitrone. Enhanced radical formation was corroborated by increased consumption of pyrogallol red, free Trp and Trp-containing peptides when these were exposed to AAPH@CB7 in the presence of light. The increased yield of radicals generated by AAPH@CB7 is believed to arise from a pull effect of CB7 portals on initial AAPH-derived carbon-centered radicals generated by photolysis. It is proposed that these radicals are exposed and released to the bulk solution and react with O2 to give peroxyl radicals. These results suggest that the AAPH@CB7 complex can be used to generate high yields of peroxyl radicals for their use in studying these species in material, environmental and biomedical sciences amongst others.
- ItemPeroxyl radical- and photo-oxidation of glucose 6-phosphate dehydrogenase generates cross-links and functional changes via oxidation of tyrosine and tryptophan residues(2017) Leinisch, Fabian; Mariotti, Michele; Rykaer, Martin; López Alarcón, Camilo Ignacio; Davies, Michael J.; Hagglund, Per
- ItemRiboflavin-induced Type 1 photo-oxidation of tryptophan using a high intensity 365 nm light emitting diode(2019) Silva, Eduardo; Barrias, Pablo; Fuentes Lemus, Eduardo Felipe; Tirapegui, Cristian; Aspee, Alexis; Carroll, Luke; Davies, Michael J.; López Alarcón, Camilo Ignacio
- ItemThe peroxyl radical-induced oxidation of Escherichia coli FtsZ and its single tryptophan mutant (Y222W) modifies specific side-chains, generates protein cross-links and affects biological function.(2017) Escobar Álvarez, Elizabeth; Leinisch, Fabian; Araya, Gissela; Monasterio, Octavio; Lorentzen, Lasse G.; Silva, Eduardo; Davies, Michael J.; López Alarcón, Camilo Ignacio