Purpose

The anorectic effect of PYY_3–36 makes it a potential pharmacological weight loss treatment. Modifications of the endogenous peptide to obtain commercially attractive pharmacological and biophysical stability properties are examined.

Methods

Half-life extended PYY_3–36 analogues were prepared and examined regarding Y₂-receptor potency as well as biophysical and stability properties.

Results

Deamidation of asparagine in position 18 and 29 was observed upon incubation at 37°C. Asparagine in position 18 – but not position 29 – could be substituted to glutamine without detrimental effects on Y₂-receptor potency. Covalent dimers were formed via the phenol impurity benzoquinone reacting with two N-terminal residues (Isoleucine-Lysine). Both residues had to be modified to suppress dimerization, which could be done without negatively affecting Y₂-receptor potency or other stability/biophysical properties. Introduction of half-life extending modifications in position 30 and 35 eliminated aggregation at 37°C without negatively affecting other stability properties. Placement of a protracting moiety (fatty acid) in the receptor-binding C-terminal region reduced Y₂-receptor potency substantially, whereas only minor effects of protractor position were observed on structural, biophysical or stability properties. Lipidated PYY_3–36 analogues formed oligomers of various sizes depending on primary structure and solution conditions.

Conclusions

By rational design, a chemically and physically stable Y₂-receptor selective, half-life extended PYY_3–36 peptide has been developed.

中文翻译：

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稳定 PYY3-36 肽 Y2 受体激动剂的合理开发

目的

_{PYY 3-36}的厌食作用使其成为一种潜在的药物减肥治疗。检查内源肽的修饰以获得商业上有吸引力的药理学和生物物理稳定性特性。

方法

制备了半衰期延长的 PYY _3-36类似物，并检查了 Y ₂受体效力以及生物物理和稳定性特性。

结果

在 37°C 温育时观察到位置 18 和 29 的天冬酰胺脱酰胺。18 位天冬酰胺——但不是 29 位——可以被谷氨酰胺替代，而不会对 Y ₂受体效力产生不利影响。通过苯酚杂质苯醌与两个 N 末端残基（异亮氨酸-赖氨酸）反应形成共价二聚体。必须修饰两个残基以抑制二聚化，这可以在不对Y ₂ -受体效力或其他稳定性/生物物理特性产生负面影响的情况下进行。在位置 30 和 35 中引入半衰期延长修饰消除了 37°C 下的聚集，而不会对其他稳定性特性产生负面影响。在受体结合的 C 末端区域放置一个延长部分（脂肪酸）减少了 Y ₂-受体效力显着，而仅观察到量角器位置对结构、生物物理或稳定性特性的轻微影响。脂化 PYY _3-36类似物根据一级结构和溶液条件形成各种大小的低聚物。

结论

通过合理设计，已开发出一种化学和物理上稳定的 Y ₂受体选择性、半衰期延长的 PYY _3-36肽。