A backbone-reversed all-beta polypeptide (retro-CspA) folds and assembles into amyloid nanofibres.

Shukla, Anshuman and Raje, Manoj and Guptasarma, Purnananda (2003) A backbone-reversed all-beta polypeptide (retro-CspA) folds and assembles into amyloid nanofibres. Protein engineering, 16 (12). pp. 875-9. ISSN 0269-2139

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Abstract

The backbone-reversed or 'retro', form of a model all-beta-sheet protein, Escherichia coli CspA, was produced from a synthetic gene in E.coli in fusion with an N-terminal affinity tag. Following purification under denaturing conditions and dialysis-based removal of urea, the protein was found to fold into a soluble, poorly structured multimer. Upon concentration, this state readily transformed into amyloid nanofibres. Congo Red-binding amorphous forms were also observed. Since a beta-sheet-forming sequence is expected to retain high beta-sheet-forming propensity even after backbone reversal and given the fact that folding of retro-CspA occurs only to a poorly structured form, we conclude that the increase effected in protein concentration may be responsible for the formation of intermolecular beta-sheets, facilitating the bleeding away of the protein's conformational equilibrium into aggregates that generate well-formed fibres. Since every molecule in these fibres contains a peptide tag for binding Ni(2+), the fibres may provide a template for deposition of nickel to generate novel materials.

Item Type:	Article
Additional Information:	Copyright of this article belongs to OUP.
Uncontrolled Keywords:	amyloid ®bre formation/backbone-reversal/protein aggregation/protein misfolding/retro modi®cation
Subjects:	Q Science > QR Microbiology
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	06 Jan 2012 14:55
Last Modified:	06 Jan 2012 14:55
URI:	http://crdd.osdd.net/open/id/eprint/221

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