The bulky dehydroamino acids dehydrovaline (ΔVal) and dehydroethylnorvaline (ΔEnv) can be inserted into the turn regions of β-hairpin peptides without altering their secondary structures. These residues increase proteolytic stability, with ΔVal at the (i + 1) position having the most substantial impact. Additionally, a bulky dehydroamino acid can be paired with a d-amino acid (i.e., d-Pro) to synergistically enhance resistance to proteolysis. A link between proteolytic stability and peptide structure is established by the finding that a stabilized ΔVal-containing β-hairpin is more highly folded than its Asn-containing congener.

中文翻译：

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大体积脱氢氨基酸增强 β-发夹肽的蛋白水解稳定性和折叠

大体积的脱氢氨基酸脱氢缬氨酸 (ΔVal) 和脱氢乙基正缬氨酸 (Δ E nv) 可以插入 β-发夹肽的转角区域，而不改变其二级结构。这些残基增加了蛋白水解稳定性，其中 ( i + 1) 位置处的 ΔVal 具有最显着的影响。此外，大体积的脱氢氨基酸可以与d-氨基酸（即d -Pro）配对以协同增强对蛋白水解的抵抗力。通过发现稳定的含 ΔVal 的 β-发夹比含 Asn 的同源物折叠程度更高，建立了蛋白水解稳定性和肽结构之间的联系。