Mannose-Binding Protein C (MBP-C) belongs to the Collectin family of innate immune defense proteins. MBL binds to an array of carbohydrate patterns on pathogen surfaces. Collectin family members share common structural features: a cysteine rich amino-terminal domain, a collagen-like region, an α-helical coiled-coil neck domain and a carboxy terminal C-type Lectin or carbohydrate recognition domain (CRD). MBL homotrimerizes to form a structural unit joined by N-terminal disulfide bridges. These homotrimers further associates into oligomeric structures of up to 6 units. Whereas two forms of MBL proteins exist in rodents and other animals. Human MBL-2 is 25 kDa. Human MBL-2 is a secreted glycoprotein that is synthesized as a 248 amino acid (aa) precursor that contains a 20 aa signal sequence, a 21 aa cysteine-rich region, a 58 aa collagen-like segment and a 111 aa C-type lectin domain that binds to neutral bacterial carbohydrates.