Secondary structure binding motifs of the jet cooled tetrapeptide model Ac-Leu-Val-Tyr(Me)-NHMe.
In this paper the structure of the isolated tetrapeptide model Ac-Leu-Val-Tyr(Me)-NHMe (Leu = leucine, Val = valine, Tyr = tyrosine) is investigated by mass- and isomer-selective IR/UV double resonance spectroscopy. Two isomers of this peptide are observed and in combination with force field, ab initio, and DFT calculations these structures are assigned to folded arrangements presenting two different secondary structure binding motifs: (a) a combined gamma-turn/beta-turn structure and (b) a triple gamma-turn structure, which is described for the first time for an isolated model system in the gas phase.
Fricke
H
H
Heinrich-Heine Universität Düsseldorf, Institut für Physikalische Chemie I, Universitätsstrasse 26.33.O2, 40225 Düsseldorf, Germany.
Schäfer
G
G
Schrader
T
T
Gerhards
M
M
D020816:Amino Acid Motifs; D001665:Binding Sites; D007536:Isomerism; D013058:Mass Spectrometry; D009842:Oligopeptides / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
C524084:Ac-Leu-Val-Tyr(Me)-NHMe; D009842:Oligopeptides