Transthyretin/Prealbumin: Proteins and Enzymes

Transthyretin (TTR), previously called thyroxin-binding prealbumin, is a 55 kDa homotetramer found in plasma that is responsible for the transport of the thyroid hormone T4 and retinol binding protein (RBP). It slows renal clearance of T4 and RBP due to megalin-mediated re-uptake of TTR complexes in the renal tubules. TTR is also found in tissues including the brain. Numerous human polymorphisms have been associated with aggregates found in familial amyloidotic polyneuropathies (FAP).