Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 73-80). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 94 pages. Includes Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 106-121). Also available via the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 86-100). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 127-134). Also available on the World Wide Web.

Syntheses, spectral, electrochemical, and spectroelectrochemical studies of iron, cobalt, and manganese phthalocyanines are reported. The novel coordination of cobalt tetracarboxy metallophthalocyanine to an electrode premodified with aryl radicals and its use in the detection of thiocyanate are reported. This work describes the catalytic activity of cobalt phthalocyanine (CoPc) derivatives adsorbed onto glassy carbon electrodes for the electrocatalytical detection of nitrite, Lcysteine, and melatonin. The modified electrodes efficiently detected nitrite. The CoPc derivative modified electrodes proficiently detected L-cysteine whereas an un-modified electrode could not. This work presents the innovative electrochemical detection of melatonin using electrodes adsorbed with CoPc derivatives. These electrodes detected melatonin at more favorable electrochemical parameters relative to an un-modified gold electrode. The limits of melatonin detection of the modified electrodes lay in the 10⁻⁷ to 10⁻⁶ M region. The modified electrodes accurately detected capsule melatonin concentrations as specified by the supplier and could differentiate between a mixture of melatonin, tryptophan, and ascorbic acid. They reliably detected nitrite, L-cysteine, and melatonin in the 10⁻⁴ to 10⁻² M region. Metallophthalocyanine complexes substituted with thio groups were employed as self assembled monolayers (SAMs). Voltammetry, impedance, atomic force microscopy, and scanning electrochemical microscopy proved that the SAMs all act as selective and efficient barriers to ion permeability. All the SAMs in this work can be used as effective electrochemical sensors of nitrite and L-cysteine in the 10⁻⁴ to 10⁻² M region with competitive limits of detection whereas an un-modified electrode cannot detect Lcysteine. The manganese phthalocyanine SAM modified electrodes are arguably better nitrite and L-cysteine electrocatalysts relative to their iron and cobalt counterparts. Manganese phthalocyanines were used as superoxide dismutase (SOD) mimics. All manganese phthalocyanine complexes in this work acted as SOD mimics in an enzymatic system of superoxide production. From cellular studies, complexes 6d, 6e, 8d, 8e act as intracellular SOD mimics and are without significantly high cellular toxicity.

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The anaerobes Actinomyces naeslundii, A. odontolyticus and Actinomyces strain ii E1S.25D produce a Mn-containing superoxide dismutase (MnSOD). Actinomyces, once classified as yeast based on their morphology, are saprophytic organisms found among the normal flora of the mouth but can act as endogenous pathogens resulting in gingivitis and actinomycosis. The ability of Actinomyces to scavenge superoxide may increase survival of the cell from the O₂⁻-dependent killing by polymorphonuclear leukocytes and also enable the organism to be transported through an oxygenated environment from one site to another. The MnSODs were purified 85-240 fold from crude extracts with 30-60% yield by two chemical fractionations and three chromatography steps. The enzymes, M_r 96,000, were tetramers of equally sized, noncovalently associated subunits similar to the MnSOD found in Saccharomyces cerevisiae. Each of the Actinomyces MnSODs contained 0.5 g-atoms Mn/subunit and were stable in the presence of 1 mM NaCN, 1 mM NaN₃ and 2.5 mM H₂O₂. The MnSODs from Actinomyces have isoelectric points of 4.2-4.6 and are negatively charged at physiological pH. Amino acid analyses of the high molecular weight MnSODs from Actinomyces, yeast, chicken liver, and Thermus thermophilus indicated similar composition of each subunit. The second order rate constants of each Actinomyces MnSOD were measured at pH 7.8 and found to be in the range of 0.9 - 2.8 x 10⁹ M⁻¹ sec⁻¹ as compared to the rate of 1.8 x 10⁹ M⁻¹ sec⁻¹ for yeast MnSODs. Structural relatedness was evaluated by immunological studies. Rabbit antisera to each of the Actinomyces MnSODs were prepared. The MnSODs from A. naeslundii and Actinomyces strain E1S.25D both showed complete identity with their respective antibodies and partial identity with the antibody prepared against A. odontolyticus MnSOD. None of the antisera cross reacted with bovine Cu/Zn SOD, Bacteroides Fe- or MnSOD or MnSODs from either Haemophilus influenzae, Deinococcus radiodurans, or S. cerevisiae. / Ph. D.

The effect of various growth conditions on the type of superoxide dismutase (SGD) formed anaerobically in three Bacteriodes species was studied. B. fragilis, B. distasonis, and B. thetaiotaomicron were grown in ironâ restricted media with or without manganese supplementation. Iron availability was decreased by treatment of the media with chelex-100, a metal-chelating resin, and addition of desferrioxamine mesylate (desferal, Ciba-Geigy), an iron chelator. Mn-containing (MnSOD) and Fe-containing superoxide dismutase (EeSOD) activities in cell extracts were differentiated by inhibition with azide and inactivation by H₂0₂. The amount of Mn-containing superoxide dismutase was estimated by the fraction of azide- and H₂0₂, -resistant activity. Cells grown in untreated media contained approximately 90% FeSOD and 10% MnSOD. Cells grown in Fe-restricted media supplemented with graded amounts of manganese synthesized a progressively larger fraction of MnSOD. Hemin, added to the Fe-restricted media, did not serve as an iron source for FeSOD formation. Superoxide dismutase specific activities varied (3-6 U/mg) in each extract but not as a function of manganese concentration. / Master of Science