Major Basic Proteins
| Major Basic Proteins | ||
|---|---|---|
|
||
| according to PDB 2BRS | ||
| other names |
Proteoglycan 2 |
|
| Properties of human protein | ||
| Mass / length primary structure | 25,206 Da / 222 amino acids | |
| Identifier | ||
| Gene name | PRG2 | |
| External IDs | ||
| Occurrence | ||
| Homology family | HOG000261603 | |
Major Basic Protein is the name of a group of relatively small proteins that only consist of a chain of polypeptides and that are rich in arginine residues . They are probably formed from a precursor rich in glutamine and aspartic acid . This precursor is non-toxic and can therefore be safely transported through the endoplasmic reticulum ; it is only in the granules that it matures into an effective MBP . In humans, it is on the one hand pregnancy-associated MBP, which is secreted by eosinophilic granulocytes ( UniProt P13727 ) and its homologue in the bone marrow proteoglycan 3 ( UniProt Q9Y2Y8 ).
MBP is toxic to mammalian cells (especially bronchial epithelia ) and helminths and is therefore involved in immune reactions against parasites . It also has the ability to stimulate mast cells to release histamine , which is why it also plays a role in inflammatory processes and overreactions of the immune system.
It also inactivates the anaphylaxis mediator SRS-A.
Occurrence
MBP occurs, for example, in the granules of eosinophilic granulocytes , a representative of the leukocytes (white blood cells). Eosinophil granulocytes are part of the immune system and are involved in the defense against parasites.