Immobilization of oxyreductases on inorganic supports based on alumina. Immobilization of lactate dehydrogenase on alumina by adsorption

• Published in: Biotechnology and bioengineering 1981-08, Vol.23 (8), p.1721-1734
• Main Authors: Kovalenko, G. A., Shitova, N. B., Sokolovskii, V. D.
• Format: Article
• Language: English
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.260230805

Lactate dehydrogenase (LDH) was adsorbed on low‐(γ, η) and high ‐(θ, α) temperature forms of alumina. θ‐Al2O3 exhibited the greatest adsorption ability. The maximum adsorption value was 30 mg LDH/g of a carrier. The conditions for irreversible adsorption have been determined. An adsorption isotherm on θ‐Al2O3 for pH 6.0 has been obtained; the LDHads surface area and the carrier surface portion accessible to the enzyme molecules have been calculated. The reaction kinetic parameter were determined by taking into account the reaction proceeding in the intradiffusional region. The specific catalytic activity (Aspec) of LDHads at small surface coverage of θ‐Al2O3 is five times less than Aspec of the native enzyme and KMimm with respect to NADH exceeds KMnat by two orders or magnitude. The is evidence for a strong LDH–Al2O3 interaction and a considerable deformation of the enzyme globule. Aspec and KM decrease as the amount of the enzyme attached to the carrier increases. Due to adsorption. LDH becomes thermostable and durable. The LDHads samples conserve 20–40% of their activity at room temperature during a year.