Antagonists of monocyte chemoattractant protein 1 identified by modification of functionally critical NH2-terminal residues.
Monocyte chemoattractant protein (MCP)-1 analogues were designed to determine the role of the NH2-terminal region in structure and function. The NH2-terminal residue was important for function and receptor binding, as it could not be deleted or extended. However the NH2-terminal pyroglutamate residue of the wild type was not essential as it could be replaced by several other noncyclic amino acids without loss of activity. Residues 7-10 were essential for receptor desensitization, but were not sufficient for function, and the integrity of residues 1-6 were required for functional activity. A peptide corresponding to MCP-1, 1-10 lacked detectable receptor-binding activities, indicating that residues 1-10 are essential for MCP-1 function, but that other residues are also involved. Several truncated analogues, including 8-76, 9-76, and 10-76, desensitized MCP-1-induced Ca2+ induction, but were not significantly active. These analogues were antagonists of MCP-1 activity with the most potent being the 9-76 analogue (IC50 = 20 nM) The 9-76 specifically bound to MCP-1 receptors with a Kd of 8.3 nM, which was three-fold higher than MCP-1 (Kd 2.8 nM). The 9-76 analogue desensitized the Ca2+ response to MCP-1 and MCP-3, but not to other CC chemokines, suggesting that it is MCP receptor specific. The availability of these compounds will be helpful in evaluating MCP receptor antagonists as anti-inflammatory therapeutics.
Biomedical Research Centre, University of British Columbia, Vancouver, Canada.
J H
JH
Gong
I
I
Clark-Lewis
D000577:Amides / Q000737:chemistry; D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D018932:Chemokine CCL2; D002630:Chemotactic Factors / Q000037:antagonists & inhibitors* / Q000737:chemistry; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine / Q000378:metabolism
D000577:Amides; C515334:CCR2 protein, human; D018932:Chemokine CCL2; D002630:Chemotactic Factors; D016207:Cytokines; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine; D002118:Calcium