The clickable activity-based probe of anti-apoptotic calenduloside E

Area of Science:

• Pharmacology
• Biochemistry
• Molecular Biology

Background:

• Calenduloside E (CE), a natural product from Aralia elata, exhibits significant anti-apoptotic properties.
• Heat shock protein 90 AB1 (Hsp90AB1) was previously identified as an anti-apoptotic target of CE using a specific probe.

Purpose of the Study:

• To investigate a CE analogue (CEA) as a clickable activity-based probe.
• To explore additional anti-apoptotic targets of CE using the novel CEA probe.

Main Methods:

• Utilized human umbilical vein endothelial cells (HUVECs) pretreated with CEA and stimulated with oxidized low-density lipoprotein (ox-LDL).
• Employed flow cytometry, JC-1 staining, and Surface Plasmon Resonance (SPR) with Biacore T200 for kinetic analysis.
• Conducted molecular modeling and docking studies to assess CE and CEA binding to Hsp90.

Main Results:

• CEA exhibited a clear anti-apoptotic effect in HUVECs.
• Hsp90 was identified as a high-scoring probable target for both CE and CEA.
• Molecular modeling indicated similar binding interactions between CE/CEA and Hsp90, with SPR confirming CEA-Hsp90 interaction (KD = 11.7 µM).

Conclusions:

• The clickable probe CEA effectively alleviates ox-LDL-induced apoptosis via mechanisms similar to CE.
• CEA provides a valuable tool for identifying further anti-apoptotic targets of CE.