Background: Osmotin-Like Proteins (OLPs) have been purified and characterized from different plant tissues, including latex fluids. Besides its defensive role, tobacco osmotin seems to induce adiponectin-like physiological effects, acting as an agonist. However, molecular information about this agonistic effect on adiponectin receptors has been poorly exploited and other osmotins have not been investigated yet.

Objective and Methods: The present study involved the characterization of three OLPs from Plumeria rubra latex and molecular docking studies to evaluate the interaction between them and adiponectin receptors (AdipoR1 and AdipoR2).

Results: P. rubra Osmotin-Like Proteins (PrOLPs) exhibited molecular masses from 21 to 25 kDa and isoelectric points ranging from 4.4 to 7.7. The proteins have 16 cysteine residues, which are involved in eight disulfide bonds, conserved in the same positions as other plant OLPs. The threedimensional (3D) models exhibited the three typical domains of OLPs, and molecular docking analysis showed that two PrOLP peptides interacted with two adiponectin receptors similarly to tobacco osmotin peptide.

Conclusion: As observed for tobacco osmotin, the latex osmotins of P. rubra exhibited compatible interactions with adiponectin receptors. Therefore, these plant defense proteins (without known counterparts in humans) are potential tools to study modulation of glucose metabolism in type II diabetes, where adiponectin plays a pivotal role in homeostasis.

背景：渗透压样蛋白（OLP）已从包括乳胶液在内的不同植物组织中纯化和鉴定。除其防御作用外，烟草渗透素似乎还可以诱导类似脂联素的生理作用，并起激动剂的作用。然而，关于这种对脂联素受体的激动作用的分子信息尚未得到充分利用，尚未对其他渗透素进行研究。

目的和方法：本研究涉及表征红鸡蛋花乳胶中的三种OLP，并进行分子对接研究以评估它们与脂联素受体（AdipoR1和AdipoR2）之间的相互作用。

结果：红杨渗透蛋白样蛋白（PrOLPs）的分子量为21至25 kDa，等电点为4.4至7.7。这些蛋白质有16个半胱氨酸残基，与8个二硫键有关，与其他植物OLP的位置相同。三维（3D）模型显示了OLP的三个典型域，并且分子对接分析表明，两个PrOLP肽与两个脂联素受体的相互作用类似于烟草渗透素肽。

结论：如对烟草渗透素的观察，红杨乳胶渗透素与脂联素受体表现出相容的相互作用。因此，这些植物防御蛋白（人类中尚无已知的对应蛋白）是研究II型糖尿病中葡萄糖代谢调节的潜在工具，其中脂联素在体内平衡中起着关键作用。