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Organic solvent mediated self‐association of an amyloid forming peptide from β 2 ‐microglobulin: An atomic force microscopy study
Author(s) -
Chaudhary Nitin,
Singh Shashi,
Nagaraj Ramakrishnan
Publication year - 2008
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.21087
Subject(s) - chemistry , beta 2 microglobulin , atomic force microscopy , peptide , amyloid (mycology) , amyloid fibril , organic solvent , microscopy , biophysics , crystallography , nanotechnology , biochemistry , chemical engineering , amyloid β , inorganic chemistry , disease , pathology , immunology , medicine , materials science , engineering , biology
Abstract Human β 2 ‐microglobulin (β 2 m) forms amyloid fibrils in hemodialysis related amyloidosis. Peptides spanning the β strands of β 2 m have been shown to form amyloid fibrils in isolation. We have studied the self‐association of a 13‐residue peptide Ac‐DWSFYLLYYTEFT‐am (Pβ 2 m) spanning one of the β‐strands of human β 2 ‐microglobulin when dissolved in various organic solvents such as methanol (MeOH), trifluoroethanol (TFE), hexafluoroisopropanol (HFIP), and dimethylsulfoxide. We have observed that Pβ 2 m forms amyloid fibrils when diluted from organic solvents into aqueous buffer at pH 7.0 as judged by increase in thioflavin T fluorescence. Fibril formation was observed to depend on the solvents in which peptide stock solutions were prepared. Circular dichroism spectra indicated propensity for helical conformation in MeOH, TFE, and HFIP. In buffer, β‐structure was observed irrespective of the solvent in which the peptide stock solutions were prepared. Atomic force microscopy images obtained by drying the peptide on mica from organic solvents indicated the ability of Pβ 2 m to self‐associate to form nonfibrillar structures. Morphology of the structures was dependent on the solvent in which the peptide was dissolved. Peptides that have the ability to self‐associate such as amyloid‐forming peptides would be attractive candidates for the generation of self‐assembled structures with varying morphologies by appropriate choice of surfaces and solvents for dissolution. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 85:783‐791, 2008. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com