Definitions for opsoninˈɒp sə nɪn
This page provides all possible meanings and translations of the word opsonin
Random House Webster's College Dictionary
op•so•ninˈɒp sə nɪn(n.)
any of several constituents of blood serum, as an antibody or complement, that make invading microorganisms more susceptible to destruction by phagocytes.
Origin of opsonin:
1900–05; < L opsōn(ium) victuals
an antibody in blood serum that attaches to invading microorganisms and other antigens to make them more susceptible to the action of phagocytes
Any antibody that causes an invading species to be more susceptible to phagocytosis
An opsonin, is any molecule that enhances phagocytosis by marking an antigen for an immune response. However, the term is usually used in reference to molecules that act as a binding enhancer for the process of phagocytosis, especially antibodies, which coat the negatively charged molecules on the membrane. Molecules that activate the complement system are also considered opsonins. Phagocytic cells do not have an Fc receptor for IgM, making IgM ineffective in assisting phagocytosis. However, IgM is extremely efficient at activating complement and is, therefore, considered an opsonin. Opsonins can also refer to molecules that target a cell for destruction through the action of natural killer cells.
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