Assembly of the full-length recombinant mouse prion protein I. Formation of soluble oligomers

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• 作者：Charlotte Vendrely ; Hé ; lè ; ne Valadié ; Lucie Bednarova ; Laurent Cardin ; Marielle Pasdeloup ; Jé ; remy Cappadoro ; Jan Bednar ; Marguerite Rinaudo and Marc Jamin
• 关键词：Prion protein ; Protein aggregation ; Protein assembly ; Multi-angle laser light scattering ; Fourier transform infrared spectroscopy
• 刊名：Biochimica et Biophysica Acta (BBA)/General Subjects
• 出版年：2005
• 期刊代码：16_03044165
• 类别：bio
• 出版时间：2005
• 卷：1724
• 期：3
• 页码：355-366
• 文件大小：337 K

摘要

The conversion of a monomeric α-helix-rich isoform to multimeric β-sheet-rich isoforms is a prominent feature of the conversion between PrP^C and PrP^SC. We mimicked this process in vitro by exposing an unglycosylated recombinant form of the full-length mouse prion protein (_MoPrP^23–231) to an acidic pH, at 37 °C, and we monitored the kinetics of conformational change and assembly. In these conditions, monomeric _MoPrP^23–231 converts slowly to two ensembles of soluble oligomers that are separated by size exclusion chromatography. The larger oligomers (I) are unstable, and their formation involves almost no change in secondary structure content. The smaller oligomers (II) form stable spherical or annular particles containing between 8 and 15 monomers as determined by multi-angle laser light scattering (MALLS). Their formation is concomitant with the main, thought limited, change in the secondary structure content (10%) seen by Fourier Transform Infrared (FTIR) spectroscopy. Even if these oligomers conserve a large part of the secondary structure of monomeric PrP, they exhibit amyloid features with the appearance of intermolecular β-structure as revealed by the appearance of an IR band below 1620 cm⁻¹.