Ramos Márcio V, Freitas Larissa B N, Bezerra Emanuel A, Morais Francimauro Sousa, Lima João P M S, Souza Pedro F N, Carvalho Cristina P S, Freitas Cleverson D T
Departamento de Bioquímica e Biologia Molecular. Fortaleza, Ceará, Universidade Federal do Ceará, CEP 60.440-970, Brazil.
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, CEP 60.440-970, Brazil.
Protein Pept Lett. 2022;29(1):89-101. doi: 10.2174/0929866528666211207111011.
The herbivores Danaus plexippus (Lepidoptera), Oncopeltus fasciatus, and Aphis nerii (Hemiptera) are special insects that feed on Calotropis procera (Apocynaceae) (Sodom Apple). At least 35 chemically distinct cardenolides have been reported in C. procera.
We aimed to evaluate the interaction between cardenolides and Na/K ATPases from herbivores.
The Na/K ATPases from these insects were modeled, and docking studies were performed involving cardenolides from C. procera.
The replacement of serine in sensitive Na/K ATPase by histidine, phenylalanine, and tyrosine in the structures examined suggested spatial impairment caused by interaction, probably making the herbivorous insects resistant against the cardenolides of C. procera. In addition, the ability of the insects to avoid cardenolide toxicity was not correlated with cardenolide polarity. Therefore, the plant fights predation through molecular diversity, and the insects, regardless of their taxonomy, face this molecular diversity through amino acid replacements at key positions of the enzyme targeted by the cardenolides.
The results show the arsenal of chemically distinct cardenolides synthesized by the C. procera.
食草动物黑脉金斑蝶（鳞翅目）、红斑蛾和夹竹桃蚜（半翅目）是取食牛角瓜（夹竹桃科）（又名索多玛苹果）的特殊昆虫。牛角瓜中已报道至少有35种化学性质不同的强心甾类化合物。
我们旨在评估强心甾类化合物与这些食草动物的钠钾ATP酶之间的相互作用。
对这些昆虫的钠钾ATP酶进行建模，并开展了涉及牛角瓜强心甾类化合物的对接研究。
在所检测结构中，敏感钠钾ATP酶中的丝氨酸被组氨酸、苯丙氨酸和酪氨酸取代，这表明相互作用导致空间损伤，可能使食草昆虫对牛角瓜的强心甾类化合物产生抗性。此外，昆虫避免强心甾类化合物毒性的能力与强心甾类化合物的极性无关。因此，植物通过分子多样性抵御捕食，而昆虫无论其分类如何，都通过强心甾类化合物作用靶点酶关键位置的氨基酸取代来应对这种分子多样性。
结果显示了牛角瓜合成的化学性质不同的强心甾类化合物库。
