Search

Your search keyword '"Kohda, Jiro"' showing total 31 results
Start Over Author "Kohda, Jiro"
31 results on '"Kohda, Jiro"'

29. Preparation of <TOGGLE>Thermus thermophilus</TOGGLE> holo-chaperonin-immobilized microspheres with high ability to facilitate protein refolding

Author

Teshima, Tadanaru, Kohda, Jiro, Kondo, Akihiko, Taguchi, Hideki, Yohda, Masafumi, and Fukuda, Hideki

Abstract

Carboxylated poly(styrene/acrylamide) (P(St/AAm)-H) microspheres with different acrylamide contents were prepared by emulsifier-free emulsion polymerization. Thermus thermophilus holo-chaperonin (cpn) was covalently immobilized onto these microspheres with high yield. The T. thermophilus holo-cpn-immobilized microspheres were used for refolding of guanidine hydrochloride (Gdn-HCl)-denatured enzymes and showed sufficiently high ability to facilitate refolding of Leuconostoc mesenteroides glucose-6-phosphate dehydrogenase (G6PD) and pig heart lactate dehydrogenase (LDH) at 30°C and Bacillus stearothermophilus LDH at 60°C. The specific ability of T. thermophilus holo-cpn-immobilized microspheres increased with increasing immobilization amount and reached plateau at around 10–15 mg/m2. When the immobilization amounts of T. thermophilus holo-cpn were approximately 10 mg/m2, the microspheres retained sufficiently high ability to facilitate protein refolding during repeated use. Therefore, the P(St/AAm)-H microspheres on which approximately 10 mg/m2 of T. thermophilus holo-cpn is immobilized are very effective for refolding of various (Gdn-HCl)-denatured enzymes over a wide temperature range. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 184–190, 2000.

Published
2000
Full Text
View/download PDF

30. Affinity Purification of Fusion Chaperonin Cpn60‐(His)6from Thermophilic Bacterium BacillusStrain MS and Its Use in Facilitating Protein Refolding and Preventing Heat Denaturation

Author

Teshima, Tadanaru, Kohda, Jiro, Kondo, Akihiko, Yohda, Masafumi, Tamura, Ai, and Fukuda, Hideki

Abstract

The cpn60 gene from Bacillusstrain MS, which is highly homologous to Bacillus stearothermophilus,was cloned. Cpn60 with a hexahistidine affinity tag (His)6fused to its C‐terminus (cpn60‐(His)6) was overproduced in Escherichia coli. Cpn60‐(His)6was expressed in a soluble form in E. coli. and purified to homogeneity in a single step by nickel chelate affinity chromatography. Cpn60‐(His)6formed a tetradecamer and had ATPase activity. Cpn60‐(His)6mediated refolding of guanidine hydrochloride unfolded pig heart malic dehydrogenase (MDH) and Thermus flavusMDH at 25 and 70 °C, respectively, in an ATP‐dependent manner. In addition, cpn60‐(His)6prevented heat denaturation of pig heart MDH and T. flavusMDH at 30 and 80 °C, respectively, in an ATP‐dependent manner. Therefore, cpn60‐(His)6facilitates protein refolding and prevents heat denaturation of proteins across a wide temperature range.

Published
2000
Full Text
View/download PDF

31. Effects of C N ratio and pH of raw materials on oil degradation efficiency in a compost fermentation process.

Author

Sasaki N, Suehara K, Kohda J, Nakano Y, and Yang T

Abstract

Waste oil treatment was attempted using a compost fermentation process. To develop a simple method for waste oil treatment, cheap and simple materials were used as compost materials. The fermentation experiment was performed using a domestic composter to determine the optimum conditions of the fermentation. Adjustment of the pH value during the compost fermentation was also important for progression of the oil degradation. When the pH value was not controlled, the pH value decreased quickly and reached about 2 and the oil degradation was stopped. Adding caustic lime to the raw materials caused the pH value of the compost to stabilize at approximately 7. The addition of a nitrogen source had a large effect on oil degradation during the compost fermentation. The optimum value of the C N ratio of the raw materials with pH control was between 10 and 40. When the C N ratio of the materials was adjusted to 10, 20, and 40, the rate constants for oil degradation were very similar. The rate constants for NH4+ consumption were also similar. Oil degradation efficiency reached 83.5% relative to the initial oil content in the compost materials. Repeated batch operation of the compost fermentation was carried out and the compost system could maintain good efficiency for oil degradation over several repeated batch operations. Finally, the compost system was applied to the treatment of recalled mayonnaise, with favorable results being obtained.

Published
2003

Catalog

Books, media, physical & digital resources
See catalog results