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Life Sciences Commons

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Physical Sciences and Mathematics

2008

Chaperone

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina Aug 2008

Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina

Faculty of Science - Papers (Archive)

The alpha-crystallins are members of the small heat shock protein (sHSP) family of molecular chaperones which have evolved to minimize intracellular protein aggregation, however they are also implicated in a number of protein deposition diseases. In this study we have employed novel mass spectrometry techniques to investigate the changes in quaternary structure associated with this switch from chaperone to adjuvant of aggregation. We have replicated the oligomeric rearrangements observed for in vivo disease-related modifications, without altering the protein sequence, by refolding the alpha-crystallins in vitro. This refolding results in a loss of dimeric substructure concomitant with an augmentation of substrate …


Protease Activation Of A2-Macroglobulin Modulates A Chaperone-Like Action With Broad Specificity, Katie French, Justin Yerbury, Mark Wilson Dec 2007

Protease Activation Of A2-Macroglobulin Modulates A Chaperone-Like Action With Broad Specificity, Katie French, Justin Yerbury, Mark Wilson

Mark R Wilson

α2-Macroglobulin (α2M) is a major human blood glycoprotein best known for its ability to inhibit a broad spectrum of proteases by a unique trapping method. This action induces an “activated” conformation of α2M with an exposed binding site for the low density lipoprotein receptor, facilitating clearance of α2M-protease complexes from the body. This report establishes that protease activation also modulates a potent chaperone-like action of α2M which has broad specificity for proteins partly unfolded as a result of heat or oxidative stress. Protease-mediated activation of α2M abolishes its chaperone-like activity. However, native α2M is able to form soluble complexes with …