G. L. Hug

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The pathogenesis of Alzheimer's disease is strongly associated with the formation and deposition of beta-amyloid peptide (beta AP) in the brain. This peptide contains a methionine (Met) residue in the C-terminal domain, which is important for its neurotoxicity and its propensity to reduce transition metals and to form reactive oxygen species. Theoretical(More)
Neutral tryptophan (*Trp) and tyrosine (TyrO(*)) radicals are repaired by certain flavonoids in buffer, in micelles and in human serum albumin (HSA) with corresponding formation of semioxidized flavonoid radicals. In deaerated buffer, *Trp but not TyrO(*) radicals react with catechin. In micelles, quercetin and rutin repair both *Trp and TyrO(*) radicals.(More)
Selective oxidative damage to apolipoprotein B in LDL can be effected radiolytically by (*)Br(2)(-) radicals. Twenty-seven Trp residues constitute major primary sites of oxidation, but two-thirds of oxidized Trps ((*)Trp) that are formed are repaired by intramolecular electron transfer from Tyr residues with formation of phenoxyl radicals (TyrO(*)).(More)
In the minor fraction of HDL3 containing alpha-tocopherol (alphaTocOH), selective one-electron oxidation of Trp and Tyr residues of apolipoproteins A-I and A-II by *Br2- radical-anions produces the corresponding semioxidized species, TyrO* and *Trp. Repair of TyrO* by endogenous alphaTocOH generates the alpha-tocopheroxyl radical (alphaTocO*). Fast(More)
Neighboring group participation was investigated in the *OH-induced oxidation of S-methylglutathione in aqueous solutions. Nanosecond pulse radiolysis was used to obtain the spectra of the reaction intermediates and their kinetics. Depending on the pH, and the concentration of S-methylglutathione, pulse irradiation leads to different transients. The(More)
The 1:1 complex of copper (II) and human serum albumin (HSA) slowly reacts with radiolytically generated *O2- radical-anion at a rate constant of 6.1 x 10(6) M(-1) s(-1). Absorbance and fluorescence spectroscopies demonstrate that addition of an equimolar portion of quercetin (QH2) to the solution of the copper (II)-HSA complex induces a relocalization of(More)
The kinetics scheme for directly excited, photoreversible reactions is solved exactly under the assumptions of no irreversible side reactions and constant excitation intensity for the duration of the reaction. The advantages of the methodology over the extrapolation-to-zero-time and the back-reaction correction methods are (i) that the quantum yields of(More)
Four polyhydroxylated 2-styrylchromones, structurally related to flavones and cinnamic acid, have been studied. An SC derivative with OH groups only at positions 3' and 4' on the styryl moiety and another SC bearing an additional OH group at position 5 on the benzopyrone ring were more potent inhibitors of the Cu2+-induced peroxidation of LDL than the(More)
The photochemistry of 2',3',5'-tri-O-acetyl-5-iodo-4-thiouridine (3) in deoxygenated 1:1 CH(3)CN-H(2)O pH 5.8 (phosphate buffer) solution has been studied by means of steady-state and nanosecond laser flash photolysis methods. Under steady-state irradiation (lambda > or = 334 nm), the stable photoproducts were iodide ion, 2',3',5'-tri-O-acetyl-4-thiouridine(More)
It has been recently shown that the inhibition of apolipoprotein A-I (apoAI) reverse cholesterol transport activity during oxidation of HDL by myeloperoxidase may involve myeloperoxidase electron transfer pathways other than those leading to tyrosine chlorination. To better understand how such mechanisms might be initiated, the role of semioxidized Tyr and(More)