Ricin - Chemical Structure And Pathological Pathway

Ricin is a protein composed of two hemagglutinins and two toxins (RCL III and RCL IV). The toxins are made up of an A polypeptide chain and a B polypeptide chain, which are joined by a disulfide bond. The general molecular structure of Ricin is similar to other biologically produced toxins, such as botulinum, cholera, diptheria and tetanus.

The B portion of Ricin binds to glycoproteins and glycolipids that terminate with galactose on the exterior of cell membranes. Ricin is then transported inside the cell by endocytosis. Once inside the cytosol of the cell, the A portion of the molecule binds to the 60S ribosome, stopping protein synthesis. A single molecule of Ricin can kill a cell.