Correction: Quantifying transient interactions between amide groups and the guanidinium cation

Abstract

Correction for 'Quantifying transient interactions between amide groups and the guanidinium cation' by V. Balos et al., Phys. Chem. Chem. Phys., 2015, 17, 28539-28543.

Spezifische Ionen‐Effekte am Beispiel eines Oligopeptids: die Rolle zweizähniger Koordination beim Guanidinium‐Kation

“…Hence, the interaction of most salts with an isolated amide group in NMA is similar to the interaction with the two amide groups and the termini of GGG. This is not true for GdmCl: while the reduction of the rotational mobility of NMA upon addition of GdmCl was moderate, [14,15,17] we find an enhanced reduction of SGGG due to GdmCl: GdmCl and LiCl affect GGG's rotation to a similar extent. The observed reduction of SGGG -so-called depolarization -is commonly observed for salts dissolved in dipolar liquids and stems from the interaction of the ions with molecular dipoles (e.g., GGG dipoles).…”

“…These observed effects for KI, KSCN, and LiCl on GGG are in qualitative agreement with effects reported for these salts interacting with NMA. [14,15,17] For KCl, where the interaction with NMA was found negligible, [14,15,17] we find a minor reduction SGGG. Hence, the interaction of most salts with an isolated amide group in NMA is similar to the interaction with the two amide groups and the termini of GGG.…”

“…To this end, we use KCl, LiCl, guanidinium chloride (GdmCl), KI and KSCN to study how different anions and cations affect GGG. Comparison to our earlier studies [14,15,17,18] on how these salts affect the rotational mobility of a model amide, N-methylacetamide (NMA), and molecular dynamics (MD) simulations on GGG in the presence of KCl, KI, and GdmCl allows us assessing the contribution of the termini on ion-specific interaction strengths. The dielectric spectrum of an aqueous solution of triglycine at cGGG =0.3 mol·L −1 .…”

“…[10] Model systems such as amide-rich molecules have been often used to elucidate ionprotein interaction. [3,[11][12][13][14][15][16][17][18] These amide models, however, lack charged residues (e.g., the C-and N-termini) that are intrinsically sensitive to electrostatic interaction with…”

Anionic and cationic Hofmeister effects are non-additive for guanidinium salts

“…[10][11][12]17,18 The most prominent interaction site for binding of ions to proteins is the amide backbone, the main structural motif common to all proteins. Variouspredominantly spectroscopic studies -have shown that interaction of ions with amide groups follow the Hofmeister series 13,[19][20][21] and it has thus been concluded that ion-amide interaction explains part of the observed destabilization of proteins. We have recently shown that the rotational mobility of a model amide, N-methylacetamide (NMA) is a very sensitive reporter of the interaction of ions with amide groups.…”