Magalie Michiel

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Mutation of the Arg120 residue in the human alphaB-crystallin sequence has been shown to be associated with a significant ability to aggregate in cultured cells and have an increased oligomeric size coupled to a partial loss of the chaperone-like activity in vitro. In the present study, static and dynamic light scattering, small-angle X-ray scattering, and(More)
The ubiquitous small heat shock proteins are essential elements in cellular protection, through a molecular chaperone activity. Among them, human small heat shock protein HspB1, HspB4 and HspB5 are involved in oncogenesis, anti-apoptotic activity and lens transparency. Therefore, these proteins are potential therapeutic targets in many diseases. Their(More)
The missense mutation Arg-120 to Gly (R120G) in the human alphaBeta-crystallin sequence has been reported to be associated with autosomal dominant myopathy, cardiomyopathy, and cataract. Previous studies of the mutant showed a significant ability to aggregate in cultured cells and an increased oligomeric size coupled to an important loss of the(More)
In aerobic cells, urate is oxidized to 5-hydroxyisourate by two distinct enzymes: a coenzyme-independent urate oxidase (EC found in eukaryotes and bacteria like Bacillus subtilis and a prokaryotic flavoprotein urate hydroxylase (HpxO) originally found in some Klebsiella species. More cases of analogous or non-homologous isofunctional enzymes (NISE)(More)
Aging of the lens is accompanied by extensive deamidation of the lens specific proteins, the crystallins. Deamidated crystallins are increased in the insoluble proteins and may contribute to cataracts. Deamidation has been shown in vitro to alter the structure and decrease the stability of human lens betaB1, betaB2 and betaA3-crystallin. Of particular(More)
Fibronectin (Fn) is a modular glycoprotein present in both the extra-cellular matrix and blood plasma. It has a cryptic zinc-metalloproteinase activity (Fn-proteinase) in the gelatin-binding domain (GBD). The nature of the enzyme's substrates and the specificity of the peptide bonds cleaved are not yet precisely known. We used mass spectrometry to(More)
Small angle X-ray scattering was used to follow the temperature and pressure induced structural transitions of polydisperse native calf lens alpha-crystallins and recombinant human alphaB-crystallins and of monodisperse yeast HSP26. The alpha-crystallins were known to increase in size with increasing temperature, whereas HSP26 partially dissociates into(More)
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