4B0F

Heptameric core complex structure of C4b-binding (C4BP) protein from human

Summary for 4B0F

• Entry DOI: 10.2210/pdb4b0f/pdb
• Related: 2A55
• Descriptor: C4B-BINDING PROTEIN ALPHA CHAIN, CHLORIDE ION (3 entities in total)
• Functional Keywords: complement system, immune system
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Secreted: P04003
• Total number of polymer chains: 7
• Total formula weight: 51780.16

Authors

Schmelz, S.,Hofmeyer, T.,Kolmar, H.,Heinz, D.W. (deposition date: 2012-07-02, release date: 2013-01-09, Last modification date: 2024-10-23)

Primary citation

Hofmeyer, T.,Schmelz, S.,Degiacomi, M.T.,Peraro, M.D.,Daneschdar, M.,Scrima, A.,Den Heuvel, J.V.,Heinz, D.W.,Kolmar, H.
Arranged Sevenfold: Structural Insights Into the C-Terminal Oligomerization Domain of Human C4B-Binding Protein.
J.Mol.Biol., 425:1302-, 2013

PubMed Abstract: The complement system as a major part of innate immunity is the first line of defense against invading microorganisms. Orchestrated by more than 60 proteins, its major task is to discriminate between host cells and pathogens and to initiate immune response. Additional recognition of necrotic or apoptotic cells demands a fine-tune regulation of this powerful system. C4b-binding protein (C4BP) is the major inhibitor of the classical complement and lectin pathway. The crystal structure of the human C4BP oligomerization domain in its 7α isoform and molecular simulations provide first structural insights of C4BP oligomerization. The heptameric core structure is stabilized by intermolecular disulfide bonds. In addition, thermal shift assays indicate that layers of electrostatic interactions mainly contribute to the extraordinary thermodynamic stability of the complex. These findings make C4BP a promising scaffold for multivalent ligand display with applications in immunology and biological chemistry.

PubMed: 23274142
DOI: 10.1016/J.JMB.2012.12.017

Experimental method

X-RAY DIFFRACTION (2.8 Å)