Development of DNA, RNA Relating Enzyme-Inhibitory Polysaccharides, Analysis of Their Inhibition Mechanism and the Application

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Inhibitory activity of polysaccharides on 5 restriction enzymes, 2 DNA ligases, and 3 reverse transcriptases was investigated. All the saccharides inhibitory to these enzymes were the ones sulfated. The inhibition was derived from the binding of these polysaccharides to enzyme proteins, but not from the binding to the substrate DNA and RNA. Therefore the level of inhibition was enzyme-dependent. Reverse transcriptases from mammal pathogens were more sensitive to polysaccharides than those from avian pathogens and DNA ligases were far more resistant to polysaccharides than reverse transcriptases.Hot water extracts of seaweeds were good sources of DNA, RNA relating enzyme-inhibitory polysaccharides. Effective constituents in these extracts were fucan sulfates in the cases of brown algae and carrageenans in the cases of red algae. Sulfur contents of these seaweed saccharide preparations were lower than those of heparin and other mucopolysaccharides of animal origin, but their inhibitory a … More ctivity was much higher than the polysaccharides from animals. These facts indicate that, in addition to the level of sulfation of saccharides, structure of the saccharide chains and the positions of sulfate in saccharide moieties have an important role for the inhibitory activity.Effective constituents in the extracts of herbs and spices were identified to be flavonoids and tannins, but glycosylation of these substances appears to be essential for the inhibitory activity.Carrageenans form gels when their hot solutions were poured into CaCl_2 solution or just cooled and, in addition, they can bind to a number of restriction enzymes with different affinities. Beads and filaments of carrageenans were regarded as good affinity gels for the purification of restriction enzymes.Crude preparations of fucan sulfate from Eisenia arborea and of clove extracts were highly inhibitory to the reverse transcriptases from M-MuLV and HIV, and the infection of HIV to MT-4 cells was completely inhibited by these preparations at the concentrations of as low as 0.15 mug/ml and 10-100 mug/ml, respectively. Less