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The role of the central flexible region on the aggregation and conformational properties of human ataxin‐3
Author(s) -
Santambrogio Carlo,
Frana Anna M.,
Natalello Antonino,
Papaleo Elena,
Regonesi Maria E.,
Doglia Silvia M.,
Tortora Paolo,
Invernizzi Gaetano,
Grandori Rita
Publication year - 2012
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2011.08438.x
Subject(s) - monomer , chemistry , thioflavin , biophysics , protein aggregation , fluorescence , fibril , crystallography , sequence (biology) , protein structure , biochemistry , biology , polymer , medicine , physics , disease , organic chemistry , pathology , quantum mechanics , alzheimer's disease
Aggregation of human ataxin‐3 (AT3) into amyloid fibrils is responsible for spinocerebellar ataxia type 3. This protein consists of a folded N‐terminal domain (Josephin domain, residues 1–182), a central flexible region (residues 183–291), a poly‐glutamine sequence of variable length and a short C‐terminal flexible region. Very little is known about the influence of the central flexible region on the conformational and aggregation properties of this protein. The present study aimed to investigate the specific role of this portion of the protein (residues 183–291). Accordingly, protein fragments 1–182 (AT3/182) and 1–291 (AT3/291) were produced and compared by thioflavin‐T fluorescence, Fourier transform infrared spectroscopy, CD, intrinsic fluorescence and ESI‐MS. It is shown that the central flexible region enhances protein aggregation and can populate conformational states with different degrees of compactness. Both monomeric and dimeric partially‐folded forms are identified for both protein fragments under denaturing conditions. Partially‐folded monomers and dimers accumulate to a larger extent in AT3/291. These species represent good candidates for early intermediates of the aggregation process under the experimental conditions employed in the present study. Structured digital abstract• Ataxin‐3 and Ataxin‐3 bind by fluorescence technology (View Interaction: 1 , 2 , 3 , 4 ) • Ataxin‐3 and Ataxin‐3 bind by mass spectrometry studies of complexes ( View interaction )