Four new series of diastereomeric β,γ-di- and β,γ-tetrapeptides derived from conveniently protected (1R,2S)- and (1S,2S)-2-aminocyclobutane-1-carboxylic acid and cis- and trans-γ-amino-l-proline joined in alternation have been synthesized. High resolution NMR experiments show that peptides containing trans-cyclobutane amino acid residues adopt a more folded structure in solution than those containing a cis-cyclobutane residue, which adopt a strand-like structure. The cis/trans relative configuration of the cyclobutane residue is the origin of the folding pattern of each peptide due to either intra- or inter-residue hydrogen-bonded ring formation, whereas the cis/trans isomerism of the γ-amino-l-proline residue does not have a significantly relevant role on the folding ability of these peptides.

衍生自方便保护的（1 R，2 S）-和（1 S，2S）-2-氨基环丁烷-1-羧酸和顺式和反式的四个新的非对映异构体β，γ-二-和β，γ-四肽已经合成了交替连接的-γ-氨基-1-脯氨酸。高分辨率NMR实验表明，与含有顺式-环丁烷残基的链状结构相比，含有反式-环丁烷氨基酸残基的肽在溶液中的折叠结构更强。在顺/环丁烷残基的相对构型是由于残基内部或残基之间氢键形成的环而引起的每个肽折叠模式的起源，而γ-氨基-1-脯氨酸残基的顺/反异构则没有这些肽的折叠能力具有显着相关的作用。