Biotechnology and Bioengineering · 1974 · 58 citations · 10 references
Life SciencesBiochemistryBiotechnologyEnzymologyMagnetic MaterialsProtein BiochemistryEnzyme CharacterizationEnzyme ImmobilizationEnzyme IsolationEnzyme StabilityImmobilized EnzymesProteolytic EnzymesCatalytic StabilityImmobilized BiocatalystsInvertase ActivityMagnetic Support ImmobilizationMagnetiteProteolytic ActivityProteolytic Enzyme ActivityProteolytic Stability
Abstract Trypsin (EC 3.4.4.4) was immobilized in low yield on aminoalkylsilylated magnetite (Fe 3 O 4 ). Better results were obtained when trypsin was immobilized by crosslinking with glutaraldehyde on magnetite. The preparation contained 36 mg protein/g magnetite and the enzyme retained 46% and 11% of esterase and proteolytic activity. Immobilized trypsin was more heat stable than trypsin. Invertase (β‐ D ‐fructofuranoside fructohydrolase, EC 3.2.1.26) was cross‐linked on magnetite with glutaraldehyde in low yield due to the inactivation of the enzyme. However in the presence of 1% sucrose, the total activity recovered was 79% of the initial activity and the preparation contained 4.4 mg/g of active invertase. Immobilized invertase was less active than invertase when acting on oligosaccharides of the raffinose family. The immobilized enzymes could be easily recovered, from solutions or suspensions, magnetically.
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