A cell attachment peptide from human C-reactive protein.
The serum acute phase reactant, C-reactive protein (CRP), is selectively deposited at sites of tissue damage and degraded by neutrophils into biologically active peptides. A synthetic peptide corresponding to residues 27-38 present in each of the five identical subunits of CRP mediated cell attachment activity in vitro. Although the CRP-derived peptide contains a Tuftsin (TKPR)-like sequence at its amino-terminus, the Tuftsin tetrapeptide itself, as well as several synthetic peptides of CRP, failed to inhibit the cell-attachment activity to the CRP-derived peptide. Peptides containing the sequences responsible for the cell attachment activity of the extracellular matrix proteins, fibronectin (Fn) and laminin, failed to inhibit the CRP-derived peptide cell attachment activity. However, the addition of the RGDS and RGDSPASSLP cell-binding peptides of Fn to cells enhanced attachment to the active peptide from CRP. In the converse experiment, the cell-binding peptide of CRP did not influence cell attachment to Fn or laminin. A peptide corresponding to the same stretch of amino acid residues within the homologous Pentraxin, serum amyloid P-component (SAP), displayed nearly identical cell-attachment activity. Several monoclonal antibodies (mAb) specific for the CRP-derived cell-binding peptide neutralized its cell-attachment activity. These mAbs reacted with intact CRP and neutralized the cell-binding activity of CRP itself. The findings suggest that a peptide with cell-binding activity could be generated from the breakdown of CRP and then contribute directly to cellular events leading to tissue repair.
Fernandez
M C
MC
Department of Microbiology, Ohio State University, Columbus 43210-1292.
Mullenix
M C
MC
Christner
R B
RB
Mortensen
R F
RF
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D002097:C-Reactive Protein / Q000737:chemistry* / Q000378:metabolism; D002448:Cell Adhesion; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D000683:Serum Amyloid P-Component / Q000378:metabolism; D014405:Tuftsin / Q000737:chemistry
D000911:Antibodies, Monoclonal; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D010455:Peptides; D000683:Serum Amyloid P-Component; D002097:C-Reactive Protein; D014405:Tuftsin