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Identification of an amyloid fibril forming segment of human Pmel17 repeat domain ( RPT domain)
Author(s) -
Louros Nikolaos N.,
Iconomidou Vassiliki A.
Publication year - 2016
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.22746
Subject(s) - chemistry , fibril , biophysics , peptide , amyloid (mycology) , fibrillogenesis , biochemistry , negative stain , organelle , electron microscope , biology , inorganic chemistry , physics , optics
Pmel17 is the major component of functional amyloid fibrils that have an important role during pigment deposition. Pmel17 polymerization is promoted within the mildly acidic conditions of melanosomes, organelles located in pigment‐specific cells. A repeat domain (RPT domain) of Pmel17, rich in glutamic acid residues has been extensively associated with the formation of the fibrous matrix. Here, we examine the RPT domain of human Pmel17 in order to provide information on this mechanism. Specifically, we have identified an aggregation‐prone peptide segment ( 405 VSIVVLSGT 413 ), close to the C‐terminal part of the RPT domain. Experimental results utilizing electron microscopy, X‐ray fiber diffraction, Congo red staining and ATR FT‐IR spectroscopy indicate that this peptide segment self‐assembles forming fibrils with evident amyloidogenic properties. Conclusively, our results demonstrate that the 405 VSIVVLSGT 413 peptide segment possibly has an essential role in RPT domain fibrillogenesis. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 133–139, 2016.