title: Chemical conjugation of linear and cyclic RGD moieties to a recombinant elastin-mimetic polypeptide--a versatile approach towards bioactive protein hydrogels.
abstract: An elastin-mimetic polypeptide, (EMM)(7), with the amino-acid sequence GRDPSS [VPGVG VPGKG VPGVG VPGVG VPGEG VPGIG](7) was used for chemical conjugation of various integrin ligands (RGD peptides) to prepare bioactive hydrogels. The chemical approach involved (1) chemical protection of lysine residues with Fmoc or Boc groups, (2) chemical ligation of a protected linear or cyclic RGD ligand, with or without a hexanoic-acid spacer to the glutamic acid residue, (3) deprotection of the lysine functionalities and the RGD moieties and (4) cross-linking to form a bioactive hydrogel. (1)H NMR spectroscopy was used to quantify the multiple steps in the reaction. The chemical protection was found to be between 65 and 93% for Fmoc and Boc, respectively. The ligands studied included linear RGD cell-binding [H-FGRGDS-OH (1-l-RGD), H-Ahx--FGRGDS-OH (2-Ahx-FGRGDS) and a cyclic -H(2)N-(CH(2))(6)COHN-cyclo(-RGDfK-) (H-Ahx-c(-RGDfK-)) peptide also with a hexanoic-acid spacer. Cell adhesion with mouse osteoblast cells was dependent on the ligand type, ligand density and the use of a spacer.
authors: TU München, Department Chemie, WACKER Lehrstuhl für Makromolekulare Chemie, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors: Doris
authors: D
authors: Kaufmann
authors: Anne
authors: A
authors: Fiedler
authors: Andreas
authors: A
authors: Junger
authors: Jörg
authors: J
authors: Auernheimer
authors: Horst
authors: H
authors: Kessler
authors: Ralf
authors: R
authors: Weberskirch
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000737:chemistry; D004549:Elastin / Q000737:chemistry* / Q000235:genetics; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D009842:Oligopeptides / Q000737:chemistry*; D010006:Osteoblasts / Q000166:cytology; D010455:Peptides / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D009842:Oligopeptides; D010455:Peptides; D011994:Recombinant Proteins; C047981:arginyl-glycyl-aspartic acid; D004549:Elastin