Amanda Penco

Annalisa Relini

Benedetta Mannini

Christopher M. Dobson

Cristina Cecchi

Fabrizio Chiti

Heath Ecroyd

Joel N. Buxbaum

Mark R. Wilson

Roberta Cascella

Sara Cappelli

Xinyi Li

Abstract
               Living systems protect themselves from aberrant proteins by a network of chaperones. We have tested in vitro the effects of different concentrations, ranging from 0 to 16 μm, of two molecular chaperones, namely αB-crystallin and clusterin, and an engineered monomeric variant of transthyretin (M-TTR), on the morphology and cytotoxicity of preformed toxic oligomers of HypF-N, which represent a useful model of misfolded protein aggregates. Using atomic force microscopy imaging and static light scattering analysis, all were found to bind HypF-N oligomers and increase the size of the aggregates, to an extent that correlates with chaperone concentration. SDS-PAGE profiles have shown that the large aggregates were predominantly composed of the HypF-N protein. ANS fluorescence measurements show that the chaperone-induced clustering of HypF-N oligomers does not change the overall solvent exposure of hydrophobic residues on the surface of the oligomers. αB-crystallin, clusterin and M-TTR can diminish the cytotoxic effects of the HypF-N oligomers at all chaperone concentration, as demonstrated by MTT reduction and Ca2+ influx measurements. The observation that the protective effect is primarily at all concentrations of chaperones, both when the increase in HypF-N aggregate size is minimal and large, emphasizes the efficiency and versatility of these protein molecules.</jats:p

Crossref

Biological Chemistry

Effect of molecular chaperones on aberrant protein oligomers <i>in vitro</i>: super-versus sub-stoichiometric chaperone concentrations

http://ro.uow.edu.au/cgi/viewcontent.cgi?article=4800&context=smhpapers

Effect of molecular chaperones on aberrant protein oligomers in vitro: super-versus sub-stoichiometric chaperone concentrations

Effect of molecular chaperones on aberrant protein oligomers in vitro: super-versus sub-stoichiometric chaperone concentrations

Abstract

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