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Mechanistic probes and inhibitors of L-pipecolate oxidaseLiang, Xi 02 December 1996 (has links)
Graduation date: 1997
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Purification and properties of d'Anjou pear (Pyrus communis, L.) polyphenol oxidaseWissemann, Kimberly Warner 11 November 1982 (has links)
Polyphenol oxidase (PPO) from d'Anjou pears was purified and some
molecular properties were studied. The extraction of PPO was
accomplished in the presence of the phenolic binder AG 2X-8 and Triton
X-100. Chlorophyll pigment was removed by chromatography resulting in
a clear, colorless enzyme extract. Three fractions of pear PPO were
purified by hydrophobic interaction chromatography on Phenyl Sepharose
CL-4B, followed by chromatography on DEAE-cellulose and hydroxylapatite
(HA). The best resolution was achieved when the columns were
developed at room temperature. Reproducibility of the entire scheme
was excellent with chromatography on the hydrophobic resin as a key to
the procedure's success. The three fractions of pear PPO were
homogeneous when stained for protein with the silver stain after
polyacrylamide gel electrophoresis and corresponded to relative
mobilities of 0.41 (HA 1), 0.43 (HA 2), and 0.73 (DEAE 3). However,
other minor protein bands were noticed on lithium dodecyl sulfate,
LDS, electrophoresis.
Dimethylsulfoxide, DMSO, was found to significantly increase the
PPO activity over the control. An 80% increase in enzyme activity was
observed when 5% DMSO was added to the enzyme fraction. Chlorogenic
acid reacted with one of the purified fractions (HA 2) at pH 7 to
yield 5 additional PPO bands upon electrophoresis. However, no
electrophoretic changes were observed with another fraction (DEAE 3)
or when 2,3-dihydroxybenzaldehyde was reacted with the two PPO
fractions.
The molecular weights of the three multiple forms of pear PPO
were similar and were 45,300 ± 5% daltons by Sephacryl S-300 gel
filtration and 59,600 ± 3% daltons by LDS electrophoresis in 10% and
gradient polyacrylamide slab gels. The isoelectric points of the
three PPO fractions were: HA 1, pi 4.3 and 4.5; HA 2, pi 4.5 and 4.7;
and DEAE 3, pI 6.9. The three fractions differed in amino acid
composition with HA 1 having a higher proportion of hydrophobic amino
acids and less charged residues than either HA 2 or DEAE 3. All three
forms of PPO contained a high proportion of the acidic amino acids
and/or their amides, and glycine. / Graduation date: 1983
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Extraction and partial characterization of strawberry polyphenol oxidaseWesche Ebeling, Pedro Alfredo E. 05 May 1980 (has links)
Graduation date: 1981
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Enediynylacridans : design and synthesis of oxidase triggered diyl progenitors /Greenwood, Stacey Noelle, January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 110-114). Also available via the Internet.
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Ueber die Oxydase der Essig-Bakterien nebst einem Anhang: Bestimmung des Alkohols durch den Gefrierpunkt /Gaunt, Rufus. January 1900 (has links)
Thesis (doctoral)--Friedrich-Wilhelms-Universität zu Berlin, 1906. / Lebenslauf. Includes bibliographical references.
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Mechanism-based Inhibitors for Copper Amine Oxidases: Synthesis, Mechanism, and EnzymologyZhong, Bo January 2010 (has links)
No description available.
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Physical studies and synthetic modeling of the molybdenum-containing enzyme sulfite oxidase.Kipke, Cary Alan. January 1988 (has links)
This research has been directed at the study of both the enzyme sulfite oxidase and molybdenum model chemistry. A modification of a previously published procedure has been used to purify sulfite oxidase in high yield which is well-suited for experiments requiring prosthetically intact enzyme and which is not contaminated with extraneous heme or with other redox active proteins. Laser flash photolysis was used to study the reaction of photoproduced 5-deazariboflavin, lumiflavin, and riboflavin semiquinone radicals with the redox centers of purified sulfite oxidase. Two distinctly different intramolecular electron transfer processes were observed between the molybdenum and heme sites of the enzyme, and these assignments were supported by flash photolysis studies of the cyanide-inactivated enzyme and the sulfite oxidase heme peptide. Microcoulometric experiments on sulfite oxidase have shown that the enzyme requires the addition of three electrons for complete subunit reduction. Midpoint potentials for the Mo(VI)/Mo(V), Mo(V)/Mo(IV), and Fe(III)/Fe(II) couples have been obtained under varied buffer conditions. The midpoint potentials obtained under High-pH and Low-pH conditions provided a means for reductively titrating the enzyme to the Mo(V) oxidation state for EXAFS studies. EXAFS of sulfite oxidase under High-pH and Low-pH conditions have provided the first example of a structural study of the three accessible oxidation states (Mo(VI), Mo(V), and Mo(IV)). A biologically relevant synthetic model for the formation of the Mo(V) Low-pH form of sulfite oxidase has been developed. The Mo(V) model compound closely resembles the minimum coordination environment for the Mo(V) Low-pH form of sulfite oxidase as determined by EXAFS. Using synchrotron radiation, molybdenum L-edge x-ray absorption spectra have been obtained for a variety of oxomolybdenum(V) compounds which serve as models for sulfite oxidase. An attempt has been made to correlate unique features of the molecules to the observed 2P → 4d electronic transitions.
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The development and application of glucose electrodes based on "wired" glucose oxidaseChen, Ting. January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from Dissertation Abstracts.
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The development and application of glucose electrodes based on "wired" glucose oxidaseChen, Ting 02 March 2011 (has links)
Not available / text
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Use of pineapple juice for inhibition of browning in applesLozano de Gonzalez, Patricia 12 December 1991 (has links)
Graduation date: 1992
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