<p>Eosinophil granule major basic protein (MBP) is a low molecular weight cationic protein present in the crystalloid core of the eosinophil granule[<cite idref="PUB00002461"/>]. It is a potent toxin for helminths and mammalian cells, and may have important roles in allergic and inflammatory reactions, it can release histamine from mast cells and damage epithelial cells of bronchial tubes.MBP is also involved in antiparasitic defence mechanisms and immune hypersensitivity reactions. The protein is a single arginine-rich polypeptide[<cite idref="PUB00001786"/>], its pro-portion being rich in glutamic and aspartic acids. It has been suggested that the protein is translated as a nontoxic precursor that protects the eosinophil from damage while it is processed through the endoplasmic reticulum to its sequestered site in the granule core toxic MBP [<cite idref="PUB00003105"/>]. The sequence of MBP has been shown to contain a C-type lectin (CTL) domain [<cite idref="PUB00003779"/>]. CTL domains are 110-130 residue motifs that appear to function as calcium-dependent carbohydrate-recognition domains [<cite idref="PUB00002461"/>, <cite idref="PUB00001786"/>, <cite idref="PUB00003105"/>].</p> Eosinophil major basic protein