Specific removal of endotoxin from protein solutions by immobilized histidine.
A method for reducing endotoxin contamination in various solutions by immobilized histidine is described. Immobilized histidine is a porous adsorbent suitable for the adsorption of endotoxin with a high affinity over a wide range of pH and temperature and at low ionic strength (gamma/2 less than or equal to 0.1). When a purified endotoxin originating from Escherichia coli UKT-B was studied, the apparent dissociation constant between endotoxin and the adsorbent was 7.3 X 10(-13) M. The adsorbent was able to remove various kinds of endotoxin originating from gram-negative bacteria; the concentration of endotoxin was reduced from 1000 to less than 0.01 ng/ml in water. It is shown that the adsorbent specifically adsorbs endotoxin provided that the adsorption conditions are properly selected. Some examples of the specific removal of endotoxin from high-molecular-weight physiologically active substances such as tumor necrosis factor and lysozyme are shown.
Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co. Ltd., Osaka, Japan.
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Matsumae
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Minobe
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Kindan
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Watanabe
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Sato
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Tosa
D000327:Adsorption; D004340:Drug Contamination; D004731:Endotoxins / Q000302:isolation & purification*; D004926:Escherichia coli; D006090:Gram-Negative Bacteria; D006639:Histidine; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009113:Muramidase / Q000302:isolation & purification; D009994:Osmolar Concentration; D011506:Proteins / Q000302:isolation & purification*; D012996:Solutions; D013696:Temperature; D014409:Tumor Necrosis Factor-alpha / Q000302:isolation & purification
D004731:Endotoxins; D011506:Proteins; D012996:Solutions; D014409:Tumor Necrosis Factor-alpha; D006639:Histidine; D009113:Muramidase