The Propensities of Amino Acids To Form Parallel β-Sheets

This paper reports synthetic and structural studies of a 16-membered combinatorial library of chemical models for parallel β-sheets ( 1 ) and two four-membered libraries of controls ( 2 and 3 ). The libraries contain glycine, alanine, valine, and leucine residues, and the structural studies use 1 H NMR and IR spectroscopy to measure the relative degrees of intramolecular hydrogen bonding of the parallel β-sheet models in chloroform solution. These studies indicate that leucine and valine are relatively good at forming parallel β-sheets, alanine is moderate, and glycine is poor (L, V > A > G).