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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Immobilization, characterization and use of fish protease

Li, Dan, 1971- January 2006 (has links)
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.
12

An investigation of the effects of the Drosophila circadian clock mutation double-time[superscript s] on double-time protein levels, nuclear localization of PER and temperature compensation

Bao, Shu. January 1999 (has links)
Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains vi, 62 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 35-42).
13

Protein and cell patterning for cell-based biosensor applications /

Veiseh, Mandana. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 222-246).
14

Immobilisation of biomolecules onto organised molecular assemblies /

Albers, Willem M. January 1999 (has links) (PDF)
Thesis (Ph. D.)--Cranfield University, 1999. / Includes bibliographical references. Also available on the World Wide Web.
15

Enzyme immobilisation and catalysis in ordered mesoporous silica /

Smith, Graham Michael. January 2008 (has links)
Thesis (Ph.D.) - University of St Andrews, March 2008. / Restricted until 14th March 2009.
16

Development of optical biosensors based on oxidases and hydrogels performing in organic phase and aqueous phase solvents

Wu, Xiaojun 01 January 2002 (has links)
No description available.
17

Immobilization, characterization and use of fish protease

Li, Dan, 1971- January 2006 (has links)
No description available.
18

Carboxypeptidase Y : purification, immobilization and applications in protein sequencing and peptide synthesis /

Hsiao, Humg-Yu January 1979 (has links)
No description available.
19

The use of immobilized oxalate oxidase in an analytical assay for urinary oxalate and in an extracorporeal shunt treatment for hyperoxaluria /

Poikey, Leonard A. January 1987 (has links)
No description available.
20

Utilization of a MAGIChip for mtDNA typing

Llewellyn, Barbara Ellen January 2003 (has links)
No description available.

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