Human C3a and C3a desArg anaphylatoxins have conserved structures, in contrast to C5a and C5a desArg.
Bajic, G., Yatime, L., Klos, A., Andersen, G.R.(2013) Protein Sci 22: 204-212
- PubMed: 23184394 
- DOI: 10.1002/pro.2200
- Primary Citation of Related Structures:  
4HW5, 4HWJ - PubMed Abstract: 
Complement is a part of innate immunity that has a critical role in the protection against microbial infections, bridges the innate with the adaptive immunity and initiates inflammation. Activation of the complement, by specific recognition of molecular patterns presented by an activator, for example, a pathogen cell, in the classical and lectin pathways or spontaneously in the alternative pathway, leads to the opsonization of the activator and the production of pro-inflammatory molecules such as the C3a anaphylatoxin ...