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Does glycation really distort the peptide α-helicity?
Laura Mariño1, Rodrigo Casasnovas1, Rafael Ramis1
1Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain.
International Journal of Biological Macromolecules
|February 11, 2019
Summary
Protein glycation, a key factor in diabetes, has unclear effects on protein structure. This study shows glycation products, like the Amadori compound, minimally impact peptide structure, clarifying glycation
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Non-enzymatic post-translational modifications, such as protein glycation, are crucial for understanding disease mechanisms.
- Protein glycation is implicated in the development of diabetes-related complications.
- Existing research presents conflicting views on whether glycation alters protein structure.
Purpose of the Study:
- To investigate the structural impact of glycation mediated by ribose and methylglyoxal on a model peptide.
- To clarify the effect of specific glycation products on peptide structure.
- To determine if glycation inherently disrupts protein structure.
Main Methods:
- Studied a fifteen-residue model peptide exhibiting a pH-induced coil-helix transition.
- Assessed the effect of ribose and methylglyoxal-mediated glycation at physiological and acidic pH.
- Identified and quantified various glycation products, including Schiff base, Amadori compound, Nε-(carboxyethyl)lysine, Nε-(carboxymethyl)lysine, and MOLD.
Main Results:
- Neither ribose nor methylglyoxal induced peptide structuration at physiological pH.
- Glycation by ribose or methylglyoxal did not significantly alter the α-helical structure of the peptide at pH ~3.
- The Amadori compound exhibited the most pronounced effect on α-helicity among the detected glycation products.
Conclusions:
- Glycation products do not necessarily destabilize or disrupt the α-helical structure of peptides.
- The structural impact of glycation is dependent on the specific modification and peptide context.
- This study provides valuable insights into the nuanced relationship between protein glycation and structural integrity.
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