10.1021/acs.jpclett.8b00348.s002
David Punihaole
David
Punihaole
Ryan S. Jakubek
Ryan S.
Jakubek
Riley J. Workman
Riley J.
Workman
Sanford A. Asher
Sanford A.
Asher
Interaction Enthalpy of Side Chain and Backbone Amides
in Polyglutamine Solution Monomers and Fibrils
American Chemical Society
2018
Q 10 fibrils
D 2 Q 10 K 2
side chain
van der Waals
Δ H int
interamide side chain interactions
Backbone Amides
amide carbonyl
dynamics simulations
Δ H int values
Polyglutamine Solution Monomers
Side Chain
amyloid-like fibril conformations
polyQ fibrils
Interaction Enthalpy
vibrational band frequencies
2018-03-23 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Interaction_Enthalpy_of_Side_Chain_and_Backbone_Amides_in_Polyglutamine_Solution_Monomers_and_Fibrils/6083078
We determined an empirical correlation
that relates the amide I
vibrational band frequencies of the glutamine (Q) side chain to the
strength of hydrogen bonding, van der Waals, and Lewis acid–base
interactions of its primary amide carbonyl. We used this correlation
to determine the Q side chain carbonyl interaction enthalpy (Δ<i>H</i><sub>int</sub>) in monomeric and amyloid-like fibril conformations
of D<sub>2</sub>Q<sub>10</sub>K<sub>2</sub> (Q10). We independently
verified these Δ<i>H</i><sub>int</sub> values through
molecular dynamics simulations that showed excellent agreement with
experiments. We found that side chain–side chain and side chain–peptide
backbone interactions in fibrils and monomers are more enthalpically
favorable than are Q side chain–water interactions. Q10 fibrils
also showed a more favorable Δ<i>H</i><sub>int</sub> for side chain–side chain interactions compared to backbone–backbone
interactions. This work experimentally demonstrates that interamide
side chain interactions are important in the formation and stabilization
of polyQ fibrils.