Abrin from Abrus precatorius (Indian liquorice/rosary pea) is a ribosome-inactivating protein (RIP) Type II. Its mechanism of cell death most closely resembles that of:
- A Ricin from Ricinus communis ✓
- B Amatoxin from Amanita phalloides
- C Tetrodotoxin from pufferfish
- D Ciguatoxin from reef fish
Correct answer: A. Ricin from Ricinus communis
Explanation
Both abrin (Abrus precatorius) and ricin (Ricinus communis) are Type II ribosome-inactivating proteins with an identical A-B chain architecture. The B chain (lectin) binds to galactose residues on cell membranes enabling endocytosis; the A chain (N-glycosidase) depurinates 28S rRNA at a specific adenine residue, irreversibly inactivating the 60S ribosomal subunit and halting protein synthesis. Amatoxin inhibits RNA polymerase II; tetrodotoxin and ciguatoxin act on sodium channels by different mechanisms.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.