Document Detail


Conformational preferences of the amylin nucleation site in SDS micelles: an NMR study.
MedLine Citation:
PMID:  12717720     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Human islet amyloid polypeptide (hIAPP), or amylin, is a 37 amino acid hormone secreted by pancreatic beta-cells. hIAPP constitutes approximately 90% of the amyloid deposits found in type II diabetic patients. It has been shown that the central region of the peptide (hIAPP(20-29)) constitutes the nucleation site for the amyloidogenic process with F23 playing a key role in the formation of the beta-pleated structures. In addition, it has been proposed that an important stage in the cytotoxicity of hIAPP is its interaction with the beta-cell membranes. As a first step toward the characterization of the interaction of hIAPP with cell membranes, we determined conformational preferences of hIAPP(20-29) in membrane-mimicking environments. We found that upon interacting with negatively charged micelles, the dominant conformation of hIAPP(20-29) is a distorted type I beta-turn centered on residues F23 and G24, with F23, A25, and I26 forming a small hydrophobic cluster that may facilitate the interaction of this peptide with the membrane bilayer. Moreover, we were able to elucidate the topological orientation of the peptide that is absorbed on the micelle surface, with the hydrophobic cluster oriented toward the hydrocarbon region of the micelles and both N- and C-termini exposed to the solvent.
Authors:
Alessandro Mascioni; Fernando Porcelli; Udayar Ilangovan; Ayyalusamy Ramamoorthy; Gianluigi Veglia
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Biopolymers     Volume:  69     ISSN:  0006-3525     ISO Abbreviation:  Biopolymers     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-04-28     Completed Date:  2003-07-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372525     Medline TA:  Biopolymers     Country:  United States    
Other Details:
Languages:  eng     Pagination:  29-41     Citation Subset:  IM    
Copyright Information:
Copyright 2003 Wiley Periodicals, Inc.
Affiliation:
Department of Chemistry, University of Minnesota, Minneapolis 55455, USA.
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Amyloid / chemistry*
Animals
Humans
Magnetic Resonance Spectroscopy
Micelles*
Models, Molecular
Molecular Sequence Data
Peptide Fragments / chemistry
Protein Conformation
Rats
Sequence Alignment
Sequence Homology, Amino Acid
Sodium Dodecyl Sulfate*
Chemical
Reg. No./Substance:
0/Amyloid; 0/Micelles; 0/Peptide Fragments; 106602-62-4/amylin; 151-21-3/Sodium Dodecyl Sulfate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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