abrin a highly toxic ∼65 kDa glycoprotein obtained from the seeds of jequirity, or Indian liquorice (Abrus precatorius L.), a tropical Asian vine that also occurs in Florida. It consists of an ∼30 kDa acidic A chain, and an ∼35 kDa neutral B chain, held together by disulfide bonds. The A chain is a powerful inhibitor of protein synthesis, while the B chain functions as a carrier to bind abrin to the membrane, and perhaps to assist penetration of the A chain into the cell. One well-chewed seed can be fatal. The A and B chains are derived from a common 528 amino acid 59.24 kDa precursor. Compare abrine, ricin.
