| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
When a biopolymer which has a biological activiy show its function, conditions suitable to form native conformation and intermolecular aggregation compete. From the viewpoint that the molecular-level aggregation of biologically active substance is similar to the pre-stage for nucleation in crystallization, the modification of yield of activity of protein by refolding which needed to avoid aggregation and the development of separation technique which utilized possibly aggregation were experimentally studied. In conclusion :
1. The addition of ammonium sulphate into an aqueous solution of papain (MW23,400) and dextran (MW19,600) of similar molecular weights made conditions of salting in and salting out for papain. Since the size of papain could be apparently changeable, the separation by ultrafiltration of papain into retentate and dextran into permeate was feasible.
Small molecules, amino acids, combined to the micelle of surfactant with different binding force due to the properties of amino acid enabled separation by ultrafiltration with high speed.
2. To increase the yield of activity of lysozyme by refolding, the effects of mixing method and electric charge were examined. The dispersion of denatured protein stained with the denaturant which depresses the aggregation into the renaturant led a high yield. Weak electric charge was also effective.
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