SFB 969 TP A02: Untersuchung der Strukturbildung von Proteinen mittels zeitaufgelöster Infrarot-Spektroskopie

Institutions
  • FB Chemie
Publications
  Popp, Alexander; Scheerer, David; Chi, Heng; Keiderling, Timothy A.; Hauser, Karin(2016): Site-specific dynamics of β-sheet peptides with DPro-Gly turns probed by laser-excited temperature-jump infrared spectroscopy ChemPhysChem ; 17 (2016), 9. - S. 1273-1280. - ISSN 1439-4235. - eISSN 1439-7641

Site-specific dynamics of β-sheet peptides with <sup>D</sup>Pro-Gly turns probed by laser-excited temperature-jump infrared spectroscopy

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Turn residues as well as side-chain interactions play an important role for the folding of ß-sheets. We investigated the conformational dynamics of a three-stranded ß-sheet peptide (<sup>D</sup>P<sup>D</sup>P) and a two-stranded ß-hairpin (WVYY-<sup>D</sup>P) by time-resolved temperature-jump infrared spectroscopy. Both peptide sequences contain <sup>D</sup>Pro-Gly residues that favor a tight ß-turn. The three-stranded ß-sheet (Ac-VFITS<sup>D</sup>PGKTYTEV<sup>D</sup>PGOKILQ-NH<sub>2</sub>) is stabilized by the turn sequences, whereas the ß-hairpin (SWTVE<sup>D</sup>PGKYTYK-NH<sub>2</sub>) folding is assisted both by the turn sequence and by hydrophobic cross-strand interactions. Relaxation times after the T-jump were monitored as a function of temperature and occur on a sub-microsecond time scale, <sup>D</sup>P<sup>D</sup>P being faster than WVYY-<sup>D</sup>P. The Xxx-<sup>D</sup>Pro tertiary amide provides a detectable IR band allowing us to site-specifically probe the dynamics. The relative importance of the turn versus the intra-strand stability in ß-sheet formation is discussed.

Origin (projects)

Funding sources
NameProject no.DescriptionPeriod
SFB912/11no information
Further information
Period: 01.01.2012 – 31.12.2015