(based on 1K24.pdb)
Backbone structure of OpcA (notice the obvious beta-pleated sheet)
Spacefilled OpcA
Highly positive lysine-rich site (blue) into which Heparin attaches
Backbone view of lysine-rich Heparin binding site
OpcA is a protein embedded in the phospholipid membrane of N. meningitidis. It allows N. meningitidis to cross the blood-brain-barrier, travelling from its normal home in the mucus membranes of the nose into the brain. Once in the brain, the bacteria wreak havoc, leaving permanent damage or even causing death.
Heparin: Bridging the Gap
(based on 1HPN.pdb)
A spacefilled view of highly negative Heparin
Heparin shown without hydrogen.
Heparin is a natural part of the body and carries out a versatile range of functions. In this case, it binds to both OpcA and Fibronectin, forming a bridge between the two.
Fibronectin
(based on 1FNH.pdb)
A backbone view of fibronectin.
A spacefilled view of fibronectin.
Fibronectin binding sites to heparin pictured in light blue and fibronectin's binding site to integrin in purple.
Fibronectin is the key that allows N. meningitidis access to the brain, binding with an ECM receptor to initiate endocytosis across the blood-brain-barrier.