Structural characterization of a monomeric chemokine: monocyte chemoattractant protein-3.
1H-NMR spectroscopy and analytical ultracentrifugation studies reveal that monocyte chemoattractant protein-3 (MCP-3) is a monomer. NMR solution structure shows that MCP-3 adopts an alphabeta fold similar to what is observed in structures of other known chemokines. However, MCP-3 is unique in that it does not show a propensity to form dimers. The closely related chemokines MCP-1 and MCP-2 show a monomer-dimer equilibrium in sedimentation equilibrium studies (approximately 0.2-2 mg/ml). As these proteins are present at nanomolar concentrations in vivo, the results suggest that they are monomeric at functional concentrations and that the monomer is the functionally significant form of MCP-1, MCP-2 and MCP-3.
Kim
K S
KS
The Protein Engineering Network of Centres of Excellence, University of Alberta, Edmonton, Canada.
Rajarathnam
K
K
Clark-Lewis
I
I
Sykes
B D
BD
D000595:Amino Acid Sequence; D018932:Chemokine CCL2 / Q000737:chemistry; D054410:Chemokine CCL7; D054412:Chemokine CCL8; D016207:Cytokines; D019281:Dimerization; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018945:Monocyte Chemoattractant Proteins / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
D018932:Chemokine CCL2; D054410:Chemokine CCL7; D054412:Chemokine CCL8; D016207:Cytokines; D018945:Monocyte Chemoattractant Proteins