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The circulating molecular chaperone clusterin interacts with amyloidogenic transthyretin oligomers and modulates amyloid formation
Author(s) -
Greene Michael J,
Klimtchuk Elena,
Koch Clarissa,
Seldin David,
Connors Lawreen H
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.996.9
Subject(s) - transthyretin , chemistry , circular dichroism , clusterin , oligomer , protein aggregation , protein folding , amyloid (mycology) , biophysics , fibril , chaperone (clinical) , congo red , proteostasis , thioflavin , biochemistry , amyloidosis , surface plasmon resonance , plasma protein binding , alzheimer's disease , biology , medicine , inorganic chemistry , apoptosis , materials science , disease , organic chemistry , pathology , adsorption , nanoparticle , nanotechnology , endocrinology
Clusterin (CLU) is an abundant, circulating chaperone co‐localizing with amyloid deposits of transthyretin (TTR). The precise interaction of CLU with misfolded, amyloidogenic TTR intermediates has not been defined. In vitro , wild‐type (WT) TTR was unfolded and aggregation induced using NaCl. Cross‐linked aggregation samples from 0–24 h showed a transition from tetramers to oligomers by SDS‐PAGE. Moreover, samples from 0.5 to 4.0 h showed increasing reactivity to the A11 oligomer‐specific antibody. Circular dichroism spectroscopy showed unfolding of native TTR structure, increased beta‐sheet content and aggregate formation. Using surface plasmon resonance (SPR) we investigated the interactions of CLU with surface‐bound native and oligomeric forms of TTR. SPR small molecule binding of Congo red (CR) to oligomers and diflunisal to native tetramers demonstrated the loss of diflunisal binding and increased CR binding to oligomeric TTR. CLU was found to bind to early and late stage oligomers in a concentration dependent manner by SPR. Amyloid formation in the presence of CLU indicated enhanced oligomerization at a 1:1 (TTR:CLU) molar ratio as measured by ThioflavinT binding. Investigation of CLU interactions with oligomeric forms of TTR may provide mechanistic insight for the presence of this chaperone in amyloid deposits. Supported by NIH grant RO1AG031804 (LHC) and the Young Family Amyloid Research Fund .