Major Basic Protein

Major Basic Protein is the name of a group of relatively small proteins that consist only of a chain of polypeptides and which are rich in arginine residues. They are probably formed by a glutamine - and Asparaginsäurereichen precursor. This precursor is non-toxic and can be safely transported through the endoplasmic reticulum, first in the granules it is matured for effective MBP. In humans, there is on the one hand, the pregnancy -associated MBP, which is secreted by eosinophils ( UniProt P13727 ) and its homologue in the bone marrow proteoglycan 3 ( UniProt Q9Y2Y8 ).

MBP is toxic to mammalian cells (especially epithelium of the bronchi ), and helminths and therefore involved in immune responses to parasites. It also has the ability to stimulate mast cells to secrete histamine, therefore, it also plays a role in inflammation and overreaction of the immune system.

It inactivated in addition also the mediator of anaphylaxis SRS -A.

Occurrence

MBP is used for example in the granules of eosinophils, a representative of leukocytes (white blood cells) before. Eosinophils are a part of the immune system and is involved in defense against parasites.