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Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca2+-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their function is to bind to oligosaccharide structure or lipids which are on the surface of microorganisms. Like other PRRs they bind pathogen-associated molecular patterns (PAMPs) and also danger-associated molecular patterns (DAMPs) of oligosaccharide origin. Binding of collectins to microorganisms may trigger elimination of microorganisms by aggregation, complement activation, opsonization, activation of phagocytosis or inhibition of microbial growth. Other functions of collectins are modulation of inflammatory, allergic responses, adaptive immune system and clearance of apoptotic cells. ==Structure== Functionally collectins are trimers. Monomeric subunit consists of four parts: * a cysteine-rich domain at the N-terminus * a collagen-like domain * a coiled-coil neck domain * a C-type lectin domain that is also called a carbohydrate recognition domain (CRD) Recognition of specific parts of microorganism is mediated by CRD in presence of calcium. Affinity of interaction between microbes and collectins depends on the degree of collectin oligomerization and also on the density of ligands on the surface of the microbe. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「collectin」の詳細全文を読む スポンサード リンク
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