cis/trans Photoisomerization of Secondary Thiopeptide Bonds

✍ Scribed by Jianzhang Zhao; Jean-Claude Micheau; Carolyn Vargas; Cordelia Schiene-Fischer

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 302 KB
• Volume: 10
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200400400

✦ Synopsis

Abstract

The reversible cis/trans photoisomerization of secondary thiopeptide bonds has been systematically studied with UV‐visible absorption, capillary electrophoresis, ^1^H NMR spectroscopy, and circular dichroism methods. It was found that the concentration of the cis conformers could be increased from less than 1 % in the thermal equilibrated solution to up to 20 % in the photostationary state. The rotational barriers of the thiopeptide bond and the pH dependence of the isomerization rates were also studied. The quantum yields of the trans→cis and the cis→trans processes were determined from photokinetic analysis.