Effects of End Group Termination on Salting-Out Constants for Triglycine.
Salting out constants for triglycine were calculated for a series of Hofmeister salts using molecular dynamics simulations. Three variants of the peptide were considered with both termini capped, just theN-terminus capped, and without capping. The simulations were supported by NMR and FTIR measurements. The data provide strong evidence that earlier experimental values of salting out constants assigned to the fully capped peptide (as previously assumed) should have been assigned to the half-capped peptide instead. Therefore, these values cannot be used to directly establish Hofmeister ordering of ions at the peptide backbone, since they are strongly influenced by interactions of the ions with the negatively chargedC-terminus.
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic.
Jana
J
Hladílková
Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany.
Jan
J
Heyda
Chemistry Department, Penn State University, University Park, PA 16802, USA.
Kelvin B
KB
Rembert
Chemistry Department, Penn State University, University Park, PA 16802, USA.
Halil I
HI
Okur
Chemistry Department, Texas A&M University, College Station, TX 77843.
Yadagiri
Y
Kurra
Chemistry Department, Texas A&M University, College Station, TX 77843.
Wenshe R
WR
Liu
Chemistry Department, Texas A&M University, College Station, TX 77843.
Christian
C
Hilty
Chemistry Department, Penn State University, University Park, PA 16802, USA.
Paul S
PS
Cremer
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic.
Pavel
P
Jungwirth
Hofmeister series; NMR; ions; molecular dynamics; triglycine