The strength of the hydrogen bonds are key in being able to extract information about the flexibility and conformation of the peptide. One technique for determining the strengths of hydrogen bonds is to study the accessibility of each hydrogen bond present to the solvent. The rate of exchange of hydrogen to deuterium over time is monitored using 1 H NMR spectroscopy. Since the deuterium from the solvent exchanges with the amide protons, the rate of decrease of the intensity of the proton peaks in the NMR spectrum is related to the exposure of the amide proton to the solvent, and thus the strength of the hydrogen bonds in the peptide.
Peptides are short chains of amino acids that can take on many structural forms.
One of the main structural forms is the helix, which is found in many proteins. Peptides containing eight Aib monomers have been shown to have the best conformation. Peptides containing six Aib monomers have been shown to have good conformation but not nearly as good as those with eight. Aib differs from the common amino acids in that it is dialkylated at the a -carbon. The steric hindrance experienced by the two a -methyl groups causes Aib containing peptides to assume helical structures.