大球盖菇咸味肽的受体感知机制研究

Study on the receptor perception mechanism of salty peptides from the Stropharia rugosoannulata mushroom

中文关键词:  咸味肽  咸味受体  竞争结合  等温滴定量热法

英文关键词:Salty peptide, salty receptor, competitive binding, isothermal titration calorimetry

中文摘要:

      目的 探究在不同咸味受体共存体系下，受体的大球盖菇咸味肽识别和结合特性，受体对咸味肽的竞争结合机制。方法 采用分子互作技术构建了多受体-肽分子竞争结合体系，研究了咸味受体ENaC的SCNN1α、SCNN1β和SCNN1γ 3个亚基受体，与咸味受体TRPV1共存体系下，对大球盖菇咸味肽KSWDDFFTR（KR-9P）的竞争结合特性。结果 咸味肽KR-9P能够同时被多种咸味受体识别和结合。SCNN1β、SCNN1γ和TRPV1受体共存的多受体-肽分子竞争结合体系中，分子间结合反应遵循焓减放热反应，肽分子数量（饱和/非饱和）和受体结合顺序，对分子间的结合影响不大，受体和肽分子之间发生多位点、多数量的分子结合，分子间结合亲和力处于强结合水平（10-8 M）。多个互作分子共存的混合体系并不利于熵驱动的SCNN1α受体结合肽分子的反应发生，分子间结合亲和力在中等水平（10-4 M）。结论 不同咸味受体在竞争结合咸味肽时展现出不同的互作机制。SCNN1β、SCNN1γ和TRPV1受体共存会产生咸味肽感知呈味增效的效果，SCNN1α和TRPV1受体之间的肽分子竞争结合，会影响SCNN1α受体感知结合咸味肽。本研究解析了不同咸味受体竞争结合咸味肽的互作机制，为理解咸味肽的受体感知机制提供参考。

英文摘要:

      Objective To explore the recognition and binding characteristics of the receptor to salty peptides of Stropharia rugosoannulata mushroom, as well as the mechanism of receptor binding competition for salty peptides, under the coexistence system of different salty receptors. Methods A multi-receptor-peptide molecule competitive binding system was constructed using molecular interaction technology. The competitive binding properties of three subunit receptors, SCNN1α, SCNN1β, and SCNN1γ, of the salty receptor ENaC to the salty peptide KSWDDFFTR (KR-9P) of the S. rugosoannulata mushroom under the system of coexistence with the salty receptor TRPV1 were investigated. Results The salty peptide KR-9P could be simultaneously recognized and bound by multiple salty receptors. In the multi-receptor-peptide molecule competitive binding system with the coexistence of SCNN1β, SCNN1γ, and TRPV1 receptors, the intermolecular binding reaction followed the enthalpy-subtracted exothermic reaction. The number of peptide molecules (saturated/non-saturated) and the order of the receptors' binding did not have much influence on intermolecular binding. Multi-site, multi-number molecular binding occurred, and the intermolecular binding affinity was at the strong binding level (10-8 M). The mixed system where multiple interacting molecules coexisted was not favorable for entropy-driven SCNN1α receptor-bound peptide molecules to occur, and the affinities of binding molecules were at the medium level (10-4 M). Conclusion Different salty receptors exhibited different interaction mechanisms when competing to bind salty peptides. The coexistence of SCNN1β, SCNN1γ, and TRPV1 receptors produced a salty peptide perceptual presentation of taste potentiation, and binding competition for peptide molecules between SCNN1α and TRPV1 receptors affected the perceptual binding of salty peptides by the SCNN1α receptor. In this study, the interactions of different salty receptors competing for binding salty peptides were revealed, which provides a reference for understanding the receptor perception mechanism of salty peptides.