Immobilization, characterization and use of fish protease
Bibliographic record
Abstract
Enzyme immobilization as a technique attaches free forms of enzyme molecules to stationary support materials to permit enzymes to be reused several times. Bovine trypsin as a model enzyme was immobilized onto controlled pore glass (CPG) beads to investigate the optimum conditions for immobilization, as well as the physico-chemical properties of the immobilized enzyme versus the free form of the enzyme. At pH 9, about 60% of the enzyme protein incubated with CPG was immobilized onto the CPG, and immobilized bovine trypsin activity was determined as 0.265 BAPNA U/g CPG beads. The immobilized bovine trypsin showed lower affinity for its substrate, lower susceptibility to inhibition by soybean trypsin inhibitor and higher thermal stability, while the optimum pH and optimum temperature values were shifted to higher values compared to those of the free enzyme. The immobilized enzyme was evaluated for its capacity to extract carotenoproteins from shrimp shell. After 11 re-uses, the immobilized enzyme retained about 77% of its initial activity, and the total yield of the product from the same immobilized trypsin was 4.3 times higher than a single use of the same amount of the free enzyme. Cunner fish is a cold water adapted, stomachless teleost fish. Cunner fish trypsin possesses some unique properties compared with homologous trypsins from (i) species acclimated to warm temperature regimes, and (ii) species with functionally distinct-stomachs. Cunner fish trypsin was extracted from pancreatic tissue, and immobilized onto CPG beads using glutaraldehyde as cross-linking reagent. The influence of enzyme loading, the properties of the immobilized enzyme in terms of specific activities, and responses to pH and temperature were investigated. The kinetic properties and operational stability of the immobilized cunner trypsin were studied as well. The pH optimum of the immobilized fish trypsin shifted from pH 8.5 to pH 9, and the temperature optimum also increased from 45ºC to 50ºC versus the free form of the cunner enzyme. The catalytic efficiencies (Vmax/Km) of the immobilized fish trypsin were determined for both amidase and esterase reactions, using BAPNA and TAME as substrates and were found to be greater than those of immobilized bovine trypsin. Thus, the immobilized cunner fish trypsin had a higher catalytic capacity for the hydrolysis of both the amide and ester substrates. The operational stability of immobilized fish trypsin was studied by extracting carotenoprotein from shrimp shell. The immobilized fish trypsin retained 75% of its initial hydrolytic capacity after 11 re-uses, and the yield obtained was over 20% higher than that of immobilized bovine trypsin. When the immobilized cunner fish trypsin was applied to digest native pectin methylesterase (PME), it exhibited greater capacity to inactivate the PME than immobilized bovine trypsin. The inactivation efficiency of the immobilized fish trypsin was 20% higher than that of the immobilized bovine trypsin. The inactivation of PME was influenced by PME concentration, incubation time and temperature. In general, higher temperature, longer incubation period, and lower initial PME concentration produced more PME inactivation. PME inactivated by immobilized fish trypsin and bovine trypsin regained part of its activity during storage at 4ºC. The initial PME concentration affected the reactivation period. The kinetic studies indicated that the inactivation rate constants increased and D-values (time to inactivate 90% of the enzyme) decreased with increasing temperature for both immobilized fish trypsin and bovine trypsin. The activation energy (Ea) of PME inactivation by the immobilized fish trypsin was lower than that by the immobilized bovine trypsin, which explains why the immobilized fish trypsin had higher catalytic capacity at various temperatures than immobilized bovine trypsin.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".