Molecular Classification
Complement protein, Glycoprotein
Other Names
C5, Complement component C5, C5a, C5b
Disease Roles
Complement Component C5 Overview
Complement component C5 is a crucial glycoprotein in the human complement system, encoded by the *C5* gene. It plays a central role in both innate immunity and inflammatory responses. Upon activation by C5 convertases, it is cleaved into C5a, a potent anaphylatoxin and chemoattractant, and C5b, which initiates the assembly of the membrane attack complex (MAC), leading to cell lysis. C5 is a therapeutic target, with drugs like Eculizumab inhibiting its activation to treat conditions like paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.
Mechanism of Action
Eculizumab prevents cleavage of C5 into C5a and C5b, thus inhibiting the formation of the membrane attack complex (MAC) and the release of the anaphylatoxin C5a.
Biological Functions
Immune response
Inflammation
Complement activation
Chemotaxis
Cell lysis
Disease Associations
Infection
Inflammation
Autoimmune diseases
Paroxysmal nocturnal hemoglobinuria
Atypical hemolytic uremic syndrome
Leiner's disease
Liver fibrosis
Rheumatoid arthritis
Safety Considerations
- Increased susceptibility to infections due to complement inhibition
Interacting Drugs
Eculizumab