We have examined in this contribution the composition dependence of binding characteristics in peptide–peptide interactions between an oligopeptide octa‐glycine and a series of tryptophan‐containing octapeptides. The binding energy associated with tryptophan–glycine interactions manifests pronounced stepwise binding characteristics as the number of tryptophan increases from 0 to 8 in the octapeptides consisting only of glycine and can be attributed to mono‐, di‐, and tri‐valent peptide–peptide interactions. At the same time, only weak fluctuations in binding energy were observed as the number of tryptophan increases from 2 to 7. Such distinctive nonlinearity of composition‐dependent tryptophan–glycine binding energy characteristics due to continuously varying tryptophan compositions in the octapeptides could be considered as a reflection of combinatorial contributions due to the hydrogen bonds originated from the indole moieties of tryptophan with the main chains of octapeptide of glycine containing N–H and C=O moieties and the van der Waals interactions (including π–π and π–CH interactions) between peptides.

中文翻译：

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色氨酸扫描诱变揭示的肽-肽相互作用的组成依赖性多价性

我们在这一贡献中研究了寡肽八甘氨酸和一系列含色氨酸的八肽之间肽-肽相互作用中结合特征的组成依赖性。与色氨酸-甘氨酸相互作用相关的结合能表现出明显的逐步结合特征，因为在仅由甘氨酸组成的八肽中色氨酸的数量从 0 增加到 8，并且可归因于单价、二价和三价肽-肽相互作用. 同时，当色氨酸的数量从 2 增加到 7 时，观察到结合能的波动很小。