- Cellular signal-responsive gene transcriptional regulation system
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A gene complex-forming material which comprises a water-soluble polymer having a peptide containing an amino acid sequence serving as the substrate of an intracellular signal-responsive enzyme and basic amino acids imparting cationic nature; a gene complex composed of this gene complex-forming material with a gene; and a gene transfer method and a gene transfer agent with the use of the same. Namely, a novel material and a method wherein the cationic moiety of the peptide and the gene form a rigid ion complex to give a stable gene complex, and, upon a cellular signal response, the positive charge of the cationic moiety of the peptide is neutralized or disappears and the gene complex is broken in the cell to thereby release the gene, thus activating the gene transferred into specific cells. The neutralization or disappearance of the positive charge can be achieved by, for example, phosphorylation with protein kinase A or cleavage by caspase.
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- Preparation and Enzymatic Hydrolysis of Polymers Anchoring Biphenyl-2-ol
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Polymers anchoring fungicidal biphenyl-2-ol(BPOL) were prepared by the polymerization and copolymerization of 2-biphenylyl methacrylate(BPMA) with various comonomers such as styrene, vinyl acetate, 2-hydroxyethyl methacrylate, N-methacryloylglycine, and N-methacryloyl-DL-alanine.The reactivity ratios of BPMA with the comonomers were evaluated.The α-chymotrypsin-catalyzed hydrolysis of the polymers was also studied.The release of BPOL from the polymers was represented by means of the Michaelis constant Km and the catalytic-rate constant kcat.The BPMA homopolymer gave higher Km and kcat values than the copolymers, and the copoly mers with a higher content of substrate units underwent cleavage more readily.It was found that the hydrolysis of the polymeric substrates is affected by the structure and character of the comonomer rather than the arrangement order of the repeating monomer units in the polymer sequence.
- Ishikawa, Tomomichi,Tanaka, Youji
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p. 1182 - 1185
(2007/10/02)
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