Cell adhesion, polypeptide sequences

Random polypeptides have traditionally been synthesized by copolymerization of amino acid NCAs. Methods for the synthesis and application of random copolymers have been extensively reviewed (e.g., ref1221), and thus only a single example is given here. A second class of random polypeptides includes organized polymeric assemblies that incorporate bioactive sequences and/or structures. Such polymers have been developed for modulation of protein-ligand interactions/231 protein adsorption to surfaces/241 and cell adhesion/25-281 Several examples for the synthesis of these polymeric assemblies are provided below. 

Saiki, I., Murata, J., Iida, J., et al. Antimetastatic effects of synthetic polypeptides containing repeated structures of the cell adhesive Arg-Gly-Asp (RGD) and Tyr-Ile-Gly-Ser-Arg (YIGSR) sequences. Br. J. Cancer 60 722-728, 1989. 

Polymers tiiat can guide development of tissue through the addition of arginine-glycine-aspartic acid (RGD) or otirer polypeptide sequences have also been fabricated. The RGD sequence of amino acids is foimd in proteins of the extracellular matrix such as fibronectin, and one of the sequence s roles is to promote cell adhesion. The purpose of synthesizing such polymers is to manipulate the body into treating the syntiretic material, which mimics the extracellular matrix, like natural tissue. If successful, cells should then readily attach and proliferate on the scaffold. Shakesheff and co-workers provide a review of the three major techniques used to create polymer-peptide hybrid materials. ... 

Figure 15 Differential growth on human umbilical vein endothelial cells plated on glass (left) or glass coated with an elastin-mimetic polypeptide containing the CSS cell adhesion sequence (right). Phase contrast optical microscopy was employed to obtain the images. Reprinted from Panitch, A. Yamaoka, T. Fournier, M. J. et at. MacromoleculesMSS, 32(5), 1701. Copyright 1999, with permission from the American Chemical Society.

In another study, the original repetitive Cio, (AGAGAGPEG)io, center was reconstructed into nine repeats of AGAGAGPEG with three distributed repeats of the RGD sequence. The new triblock protein, composed of acidic and basic terminal domains in addition to the reconstructed central block, has been shown to support adhesion, spreading, and polarization of human fibroblast cells [82]. Triblock polypeptides that facilitate antibody binding have also been reported [83]. 

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