Cross-linking and insolubilization studies of water-soluble poly(L-ornithine).
Cross-linking and insolubilization studies of water-soluble synthetic cationic polypeptides containing ornithine residues were carried out using the organic cross-linking agents glutaraldehyde (GA) and 2,5-hexanedione (HD) in water. The cross-linking reaction was characterized by the viscosity and turbidity changes. When more than a 1:5 equimolar amount of GA or a 1:2 equimolar amount of HD was added to the ornithine polypeptide systems as organic cross-linking agents, insolubilization occurred causing turbidity. As a whole, the molecular weight of the samples, the cross-linking agent used, the molar ratios between cross-linking agents and functional residues, and the system pH were found to play roles in the insolubilization reaction and gel formation. Of these factors, a system pH of 11 is the most important in insolubilization of polyornithine (PLO)-GA and PLO-HD mixed solutions. Using PLO and polylysine (PLL) samples with almost similar degrees of polymerization, the cross-linking results of the PLO systems were compared with those of the PLL systems.
Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda, Japan.
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Yamamoto
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Hirata
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Tanisho
D003124:Colorimetry; D003432:Cross-Linking Reagents; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009952:Ornithine / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry; D012995:Solubility; D014783:Viscosity; D014867:Water
D003432:Cross-Linking Reagents; D010455:Peptides; D014867:Water; C008973:polyornithine; D011107:Polylysine; D009952:Ornithine