Design and characterization of peptides with amphiphilic β-strand structures

✍ Scribed by David G. Osterman; E. T. Kaiser

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 870 KB
• Volume: 29
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240290202

✦ Synopsis

To extend our studies on peptides and proteins with amphiphilic secondary structures, a series of peptides designed to form amphiphilic 0-strand structures was designed, synthesized, and characterized by circular dichroism and infrared spectroscopy. Amphiphilic 0-strand conformations may be likely to appear in a variety of surface-active proteins, including apolipoprotein B and fibronectin. In a 0-strand conformation, the synthetic peptides will possess a hydrophobic face composed of valine side chains and a hydrophilic face composed of alternating acidic (glutamic acid) and basic (ornithine or lysine) residues. The peptides studied had a variety of chain lengths (5, 9, and 13 residues), and had the amino groups either free or protected with the trifluoroacetyl group. While the peptides did not possess a high potential for &sheet formation based on the Chou Fasman parameters, they possessed significant &sheet content, with up to 90% 0-sheet calculated for the 13-residue protected peptide. The driving force for @-sheet formation is the potential amphiphilicity of this conformation. The ,%strand conformation of the 13-residue deprotected peptide was stable in 50% trifluoroethanol, 6 M guanidine hydrochloride, and octanol. The peptides are strongly self-associating in water, which would reduce the unfavorable contacts of the hydrophobic residues with water. It is clear that small peptides can be designed to form stable 0-strand conformations.