The invention provides an isolated or purified peptide that binds at least one plasma protein. In one embodiment, the isolated or purified peptide binds to fibrinogen, comprises no more than 10 amino acids, and comprises an amino acid sequence Xaa.sub.1-Xaa.sub.2-Xaa.sub.3-Xaa.sub.4-Xaa.sub.5, an amino acid sequence Gly-Xaa.sub.6-Arg-Xaa.sub.7, or an amino acid sequence selected from specific amino acid sequences provided herein. Alternatively, the isolated or purified protein binds to .alpha.l proteinase inhibitor and/or a protein complex comprising Apo-A1 lipoprotein and paraoxonase. The peptide comprises no more than 10 amino acids and comprises an amino acid sequence Xaa.sub.8-Xaa.sub.8-Xaa.sub.1-His-Xaa.sub.1-Xaa.sub.3, and amino acid sequence His-Xaa.sub.8-Xaa.sub.9-Xaa.sub.1-Xaa.sub.10-Xaa.sub.2, or an amino acid sequence selected from specific amino acid sequences provided herein. In addition, the invention provides isolated or purified peptide that binds to von Willebrand Factor. The peptide comprises an amino acid sequence Xaa.sub.4-Xaa.sub.5-Xaa.sub.5, an amino acid sequence Tyr-Leu-Xaa.sub.11-Xaa.sub.4-Xaa.sub.12-Thr, or an amino acid sequence selected from specific amino acid sequences provided herein.