Tags

Type your tag names separated by a space and hit enter

Kinetics and stability of immobilized chicken liver xanthine dehydrogenase.
Biotechnol Bioeng. 1979 Oct; 21(10):1767-86.BB

Abstract

Xanthine dehydrogenase (EC 1.2.1.37) was isolated from chicken livers and immobilized by adsorption to a Sepharose derivative, prepared by reaction of n-octylamine with CNBr-activated Sepharose 4B. Using a crude preparation of enzyme for immobilization it was observed that relatively more activity was adsorbed than protein, but the yield of immobilized activity increased as a purer enzyme preparation was used. As more activity and protein were bound, relatively less immobilized activity was recovered. This effect was probably due to blocking of active xanthine dehydrogenase by protein impurities. The kinetics of free and immobilized xanthine dehydrogenase were studied in the pH range 7.5-9.1. The Km and V values estimated for free xanthine dehydrogenase increase as the pH increase; the K'm and V values for the immobilized enzyme go through a minimum at pH 8.1. By varying the amount of enzyme activity bound per unit volume of gel, it was shown that K'm is larger than Km are result of substrate diffusion limitation in the pores of the support material. Both free and immobilized xanthine dehydrogenase showed substrate activation at low concentrations (up to 2 microM xanthine). Immobilized xanthine dehydrogenase was more stable than the free enzyme during storage in the temperature range of 4-50 degrees C. The operational stability of immobilized xanthine dehydrogenase at 30 degrees C was two orders of magnitude smaller than the storage stability, t 1/2 was 9 and 800 hr, respectively. The operational stability was, however, better than than of immobilized milk xanthine oxidase (t 1/2 = 1 hr). In addition, the amount of product formed per unit initial activity in one half-life, was higher for immobilized xanthine dehydrogenase than for immobilized xanthine oxidase. Unless immobilized milk xanthine oxidase can be considerable stabilized, immobilized chicken liver xanthine dehydrogenase is more promising for application in organic synthesis.

Authors

No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

486718

Citation

Tramper, J, et al. "Kinetics and Stability of Immobilized Chicken Liver Xanthine Dehydrogenase." Biotechnology and Bioengineering, vol. 21, no. 10, 1979, pp. 1767-86.
Tramper J, Angelino SA, Müller F, et al. Kinetics and stability of immobilized chicken liver xanthine dehydrogenase. Biotechnol Bioeng. 1979;21(10):1767-86.
Tramper, J., Angelino, S. A., Müller, F., & van der Plas, H. C. (1979). Kinetics and stability of immobilized chicken liver xanthine dehydrogenase. Biotechnology and Bioengineering, 21(10), 1767-86.
Tramper J, et al. Kinetics and Stability of Immobilized Chicken Liver Xanthine Dehydrogenase. Biotechnol Bioeng. 1979;21(10):1767-86. PubMed PMID: 486718.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Kinetics and stability of immobilized chicken liver xanthine dehydrogenase. AU - Tramper,J, AU - Angelino,S A, AU - Müller,F, AU - van der Plas,H C, PY - 1979/10/1/pubmed PY - 1979/10/1/medline PY - 1979/10/1/entrez SP - 1767 EP - 86 JF - Biotechnology and bioengineering JO - Biotechnol Bioeng VL - 21 IS - 10 N2 - Xanthine dehydrogenase (EC 1.2.1.37) was isolated from chicken livers and immobilized by adsorption to a Sepharose derivative, prepared by reaction of n-octylamine with CNBr-activated Sepharose 4B. Using a crude preparation of enzyme for immobilization it was observed that relatively more activity was adsorbed than protein, but the yield of immobilized activity increased as a purer enzyme preparation was used. As more activity and protein were bound, relatively less immobilized activity was recovered. This effect was probably due to blocking of active xanthine dehydrogenase by protein impurities. The kinetics of free and immobilized xanthine dehydrogenase were studied in the pH range 7.5-9.1. The Km and V values estimated for free xanthine dehydrogenase increase as the pH increase; the K'm and V values for the immobilized enzyme go through a minimum at pH 8.1. By varying the amount of enzyme activity bound per unit volume of gel, it was shown that K'm is larger than Km are result of substrate diffusion limitation in the pores of the support material. Both free and immobilized xanthine dehydrogenase showed substrate activation at low concentrations (up to 2 microM xanthine). Immobilized xanthine dehydrogenase was more stable than the free enzyme during storage in the temperature range of 4-50 degrees C. The operational stability of immobilized xanthine dehydrogenase at 30 degrees C was two orders of magnitude smaller than the storage stability, t 1/2 was 9 and 800 hr, respectively. The operational stability was, however, better than than of immobilized milk xanthine oxidase (t 1/2 = 1 hr). In addition, the amount of product formed per unit initial activity in one half-life, was higher for immobilized xanthine dehydrogenase than for immobilized xanthine oxidase. Unless immobilized milk xanthine oxidase can be considerable stabilized, immobilized chicken liver xanthine dehydrogenase is more promising for application in organic synthesis. SN - 0006-3592 UR - https://www.unboundmedicine.com/medline/citation/486718/Kinetics_and_stability_of_immobilized_chicken_liver_xanthine_dehydrogenase_ L2 - https://doi.org/10.1002/bit.260211006 DB - PRIME DP - Unbound Medicine ER -