Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), University of Campania 'Luigi Vanvitelli', Via Vivaldi 43, 81100-Caserta, Italy.
Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Food Chem. 2022 Dec 1;396:133655. doi: 10.1016/j.foodchem.2022.133655. Epub 2022 Jul 9.
Ribotoxin-like proteins (RL-Ps) represent a novel specific ribonuclease family found in edible mushrooms and are able to inhibit protein synthesis. Here, we report the characterization and cytotoxic effects of four novel RL-Ps, named eryngitins, isolated from fruiting bodies of the king oyster mushroom (Pleurotus eryngii). These proteins induced formation of α-fragment from rabbit ribosomes, characteristic of their enzymatic action. The two 15 kDa eryngitins (3 and 4) are considerably more thermostable than the 21 kDa ones (1 and 2), however their overall structural features, as determined by far-UV CD spectrometry, are similar. Complete in vitro digestibility by pepsin-trypsin, and lack of cytotoxicity towards human HUVEC cells suggest low toxicity of eryngitins, if ingested. However, eryngitins exhibit cytotoxic action against insect Sf9 cells, suggesting their possible use in biotechnological applications as bioinsecticides. This cytotoxicity was not enhanced in the presence of cytolytic protein complexes based on aegerolysin proteins from Pleurotus mushrooms.
核糖体毒素样蛋白（RL-Ps）是一类存在于食用蘑菇中的新型特定核糖核酸酶家族，能够抑制蛋白质合成。本研究从金针菇（Pleurotus eryngii）子实体中分离出四种新型 RL-P，命名为乳菇菌素，并对其进行了鉴定和细胞毒性作用研究。这些蛋白能够诱导兔核糖体形成 α 片段，这是其酶促作用的特征。两种 15 kDa 的乳菇菌素（3 和 4）比 21 kDa 的乳菇菌素（1 和 2）具有更高的热稳定性，但是通过远紫外 CD 光谱法测定，它们的整体结构特征相似。胃蛋白酶-胰蛋白酶的完全体外消化以及对人脐静脉内皮细胞（HUVEC）无细胞毒性表明，如果摄入乳菇菌素，其毒性很低。然而，乳菇菌素对昆虫 Sf9 细胞表现出细胞毒性作用，这表明它们可能在生物技术应用中作为生物杀虫剂使用。在存在基于金针菇中的 aegerolysin 蛋白的细胞溶解蛋白复合物的情况下，这种细胞毒性并未增强。
