major basic protein

(redirected from PRG2)

major basic protein

a cytotoxic and proinflammatory mediator found in eosinophil granules.

major basic protein

An 11-kD major cytotoxic and helminthotoxic protein encoded by PRG2 on chromosome 11q12, which forms a characteristic crystalloid and is found in the granules of eosinophils and other myeloid cells. It induces non-cytolytic histamine release from human basophil, and is involved in antiparasitic defence and immune hypersensitivity reactions.

The adjectival “basic” derives from MBP’s isoelectric point of greater than pH 10. MBP is capable of killing parasites, as well as host cells; it causes bronchial epithelial damage and a wheal and flare response when injected subcutaneously, and it has been linked to asthma.