Serum Amyloid A (SAA)

Serum amyloid A protein is a protein encoded by the SAA1 gene.The serum amyloid A (SAA) protein is an acute phase apolipoprotein reactant produced mainly by hepatocytes and under regulation of inflammatory cytokines (summarized by Lundmark et al., 2002). The SAA cleavage product, designated amyloid protein A (AA), is deposited systemically as amyloid in vital organs including the liver, spleen, and kidneys in patients with chronic inflammatory diseases.

There is very limited structural information about SAA because of its inherent poor solubility in the apolipoprotein form. It is intriguing to understand how such a small protein is able to mediate or directly carry out such a wide range of functions related to inflammatory reaction and other hostdefense mechanisms.