Enzymatically crosslinked collagen-mimetic dendrimers that promote integrin-targeted cell adhesion.
Collagen is made up of a diverse family of the extracellular matrices, most of which are generally found crosslinked in vivo. To more closely mimic the biological function of collagen, this work focuses on establishing a molecular strategy to engineer a functional biomimetic collagen that exhibits stable collagen-like triple-helical conformation with cell-binding activity, in addition to an enzyme-mediated crosslinking by tissue transglutaminase (tTGase). A novel sequence spanning residues 2800-2807 of human fibrillin-1 (EDGFFKI) was first identified as an amine donor substrate for tTGase, using a previously characterized APQQEA derived from human osteonectin as an amine acceptor probe. Subsequently, collagen-mimetic peptides (CMPs) supplemented with a cell-binding sequence (GFOGER) and the identified EDGFFKI and APQQEA substrate sequences were conjugated onto a generation 2 poly(amidoamine) dendrimer, resulting in a crosslinkable collagen-mimetic dendrimer, denoted as CMD-K and CMD-Q, respectively. Both CMD-K and CMD-Q exhibited enhanced triple-helical stability and supported cell adhesion in an integrin-specific manner. Finally, tTGase-mediated crosslinking between CMD-K and CMD-Q resulted in a supramolecular structure that exhibited stable collagen-like triple-helical conformation and improved cellular recognition. The results show that the triple-helical structure is important in preserving the GFOGER cell-binding site while the tTGase-mediated protein crosslinking may also be crucial for the recognition by cell surface integrin receptors.
Khew
Shih Tak
ST
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 119077, Singapore. st.khew@nus.edu.sg
Yang
Qing Jun
QJ
Tong
Yen Wah
YW
D000595:Amino Acid Sequence; D002448:Cell Adhesion; D003094:Collagen / Q000737:chemistry*; D050091:Dendrimers; D000071838:Fibrillin-1; D000071837:Fibrillins; D006801:Humans; D016023:Integrins / Q000737:chemistry*; D008840:Microfilament Proteins / Q000737:chemistry; D018716:Molecular Mimicry; D054392:Adipokines
D003094:Collagen; D050091:Dendrimers; D000071838:Fibrillin-1; D000071837:Fibrillins; D016023:Integrins; D008840:Microfilament Proteins; C000605722:FBN1 protein, human; D054392:Adipokines