Title of article :
A stereochemical switch in the aDrs model system, a candidate for a functional amyloid
Author/Authors :
Gِكler-Schِfberger، نويسنده , , Ruth and Hesser، نويسنده , , Günter and Reif، نويسنده , , Maria M. and Friedmann، نويسنده , , Jacqueline and Duscher، نويسنده , , Bernadette and Toca-Herrera، نويسنده , , José Luis and Oostenbrink، نويسنده , , Chris and Jilek، نويسنده , , Alexander، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Pages :
7
From page :
100
To page :
106
Abstract :
Amyloid fibrils are commonly observed to adopt multiple distinct morphologies, which eventually can have significantly different neurotoxicities, as e.g. demonstrated in case of the Alzheimer peptide. The architecture of amyloid deposits is apparently also determined by the stereochemistry of amino acids. Post-translational changes of the chirality of certain residues may thus be a factor in controlling the formation of functional or disease-related amyloids. c dermaseptin (aDrs), an unusual peptide from the skin secretions of the frog Pachymedusa dacnicolor, assembles to amyloid-like fibrils in a pH-dependent manner, which could play a functional role in defense. aDrs can be enzymatically converted into the diastereomer [d-Leu2]-aDrs by an l/d-isomerase. EM and AFM on fibrils formed by these isomers have shown that their predominant morphology is controlled by the stereochemistry of residue 2, whereas kinetic and thermodynamic parameters of aggregation are barely affected. When fibrils were grown from preformed seeds, backbone stereochemistry rather than templating-effects apparently dominated the superstructural organization of the isomers. Interestingly, MD indicated small differences in the conformational propensities between the isomers. sults demonstrate how d-amino acid substitutions could take active part in the formation of functional or disease-related amyloid. Moreover, these findings contribute to the development of amyloid-based nanomaterials.
Keywords :
d-amino acid , SELF-ASSEMBLY , functional amyloid , posttranslational modification , Amphibian skin , Bioactive peptide
Journal title :
Archives of Biochemistry and Biophysics
Serial Year :
2012
Journal title :
Archives of Biochemistry and Biophysics
Record number :
1632813
Link To Document :
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