Dynamic heterodimer-functionalized surfaces for endothelial cell adhesion.

The functionalization of hydrogels for receptor-mediated cell adhesion is one approach for targeted cell and tissue engineering applications. In this study, polyacrylamide gel surfaces were functionalized with specific cell adhesion ligands via the self-assembly of a peptide-based heterodimer. The system was comprised of a cysteine-terminated monomer, A (MW approximately 5400), grafted to the polyacrylamide gels and a complementary ligand presenting monomer, B(X) (MW approximately 5800) that was designed to heterodimerize with A.

Analysis and design of turns in alpha-helical hairpins.

Although the analysis and design of turns that connect the strands in antiparallel beta-hairpins has reached an advanced state, much less is known concerning turns between antiparallel helices in helical hairpins. We have conducted an analysis of the structures and sequence preferences of two types of interhelical turns, each of which connects the two helices by a two-residue linker in an alphaL-beta conformation. Based on this analysis, it became apparent that the turn introduced into a designed four-helix bundle protein, DF1, did not occur within an optimal structural context.

Ultrafast folding of alpha3D: a de novo designed three-helix bundle protein.

Here, we describe the folding/unfolding kinetics of alpha3D, a small designed three-helix bundle. Both IR temperature jump and ultrafast fluorescence mixing methods reveal a single-exponential process consistent with a minimal folding time of 3.2 +/- 1.