IR spectroscopic analyses of amyloid fibril formation of ¦Â₂-microglobulin using a simplified procedure for its in vitro generation at neutral pH

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• 作者：Heinz Fabian ; Klaus Gast ; Michael Laue ; Katharina J. Jetzschmann ; Dieter Naumann ; Andreas Ziegler ; Barbara Uchanska-Ziegler
• 关键词：¦Â2m ; ¦Â2-microglobulin ; IR ; infrared ; SLS ; static light scattering ; DLS ; dynamic light scattering ; EM ; electron microscopy ; DSC ; differential scanning calorimetry ; ThT ; thioflavin T ; LS ; long straight ; WL ; worm-like ; ¦Â2m-FPhys ; ¦Â2-microglobulin fibrils
• 刊名：Biophysical Chemistry
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：179
• 期：Complete
• 页码：35-46
• 全文大小：1369 K

文摘

¦Â₂-microglobulin (¦Â₂m) is known to be the major component of fibrillar deposits in the joints of patients suffering from dialysis-related amyloidosis. We have developed a simplified procedure to convert monomeric recombinant ¦Â₂m into amyloid fibrils at physiological pH by a combination of stirring and heating, enabling us to follow conformational changes associated with the assembly by infrared spectroscopy and electron microscopy. Our studies reveal that fibrillogenesis begins with the formation of relatively large aggregates, with secondary structure not significantly altered by the stirring-induced association. In contrast, the conversion of the amorphous aggregates into amyloid fibrils is associated with a profound re-organization at the level of the secondary and tertiary structures, leading to non-native like parallel arrangements of the ¦Â-strands in the fully formed amyloid structure of ¦Â₂m. This study highlights the power of an approach to investigate the formation of ¦Â₂m fibrils by a combination of biophysical techniques including IR spectroscopy.