Title:Structural Analysis Revealed the Interaction of Cardenolides from
Calotropis procera with Na+/K+ ATPases from Herbivores
Volume: 29
Issue: 1
Author(s): Márcio V. Ramos*, Larissa B.N. Freitas, Emanuel A. Bezerra, Francimauro Sousa Morais, João P.M.S. Lima, Pedro F.N. Souza, Cristina P.S. Carvalho and Cleverson D.T. Freitas
Affiliation:
- Departamento de Bioquímica e Biologia Molecular. Fortaleza, Ceará, Universidade Federal do Ceará, CEP
60.440-970, Brazil
Keywords:
Apocynaceae, insects, plant defense, structural insights, cardenolides, herbivores.
Abstract: Background: 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.
Objective: We aimed to evaluate the interaction between cardenolides and Na+/K+ ATPases from
herbivores.
Methods: The Na+/K+ ATPases from these insects were modeled, and docking studies were performed
involving cardenolides from C. procera.
Results: 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.
Conclusion: The results show the arsenal of chemically distinct cardenolides synthesized by the C.
procera.