Thesis (Ph. D.)--University of Virginia, 1997. / Spine title: Role of Tryptophan in cytochrome b₅. Includes bibliographical references (187-196). Also available online through Digital Dissertations.

Thesis (PhD)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Edward E. Schmidt. Includes bibliographical references (leaves 137-183).

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains viii, 72 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 68-72).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Kevin N. Dalby. Vita. Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 52-62). Also available in electronic version.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Edward E. Schmidt. Includes bibliographical references (leaves 71-83).

One common method of improving the nutritional quality of certain food proteins is through fortification with necessary amounts of limiting essential amino acids. This simple and convenient method, however, is not the best. Several disadvantages are associated with the addition of free amino acids to food proteins, such as changes in flavor and color, losses of added amino acids during food processing or cooking, differences in stability and metabolism between free amino acids and amino acids in proteins. Covalent attachment of the limiting amino acids, however, should eliminate these problems, and moreover, could improve the nutritional and functional properties of food proteins. In this study, therefore, an attempt to improve the nutritional value of the soy protein was made by using the carbodiimide condensation reaction to covalently bind methionine and tryptophan to soy protein. In order to confine as much as possible the binding, of amino acid to the protein a-carboxyl groups the soy protein isolate (SPI) was partially hydrolyzed with pepsin to increase the number of a-carboxyls in soy protein. Various conditions of the carbodiimide reaction were analysed by a fractional factorial design in an attempt to determine the factors affecting the amino acid binding to soy protein hydrolysate (SPH). Of the factors investigated, pH, SPH concentration, carbodiimide concentration, activation time and reaction time were found to significantly affect the methionine binding efficiency, whereas pH, SPH concentration, carbodiimide concentration, amino acid concentration and reaction temperature were found to significantly influence the tryptophan binding efficiency to SPH. To determine the best level for each of the selected factors an optimization of the carbodiimide reaction conditions was conducted by carrying out another factorial experiment. Thus, under the best condition found, the methionine and tryptophan contents of methionine - and tryptophan-bound SPH samples were increased 7.7-fold and 18.0-fold, respectively. An in vitro pepsin-pancreatin digestion test demonstrated that the bound amino acids were readily released. In order to improve the low yield of the final product, another analysis of the carbodiimide reaction conditions was carried out. Since the yield could not be markedly improved by this factorial design in which peptic SPH was used, SPI without preliminary hydrolysis was used as the starting material. A product with 95-99% yield was obtained and its methionine or tryptophan content was increased 6.3-fold or 11.3-fold, respectively. High digestibility was still maintained for these products. Gel filtration chromatography demonstrated that the carbodiimide reaction caused an increase in the molecular weights of soy protein fractions. Furthermore, gel filtration chromatography revealed that, there was no selective amino acid binding among the different soy protein fractions during the carbodiimide reaction. / Land and Food Systems, Faculty of / Graduate

Call number: LD2668 .T4 1955 L67 / Master of Science

Arabidopsis thaliana Acyl-CoA-Binding Protein 3, one of six acyl-CoA-binding proteins, is unique by the C-terminal location of its acyl-CoA-binding (ACB) domain. It promotes autophagy (ATG)-mediated leaf senescence and confers resistance to Pseudomonas syringae pv. tomato DC3000. To understand the regulation of ACBP3, a 1.7 kb 5’-flanking region of ACBP3 and its deletion derivatives were characterized using β-glucuronidase (GUS) reporter gene fusions. A 374 bp minimal fragment (-151/+223) could drive GUS expression while a 1698 bp fragment (-1475/+223) conferred maximal activity. Further, histochemical GUS staining analysis on transgenic Arabidopsis harboring the largest (1698 bp) ACBP3pro::GUS fusion displayed ubiquitous expression in floral organs and vascular bundles of leaves and stems, consistent with previous results that extracellularly localized ACBP3 functions in plant defense. A 160 bp region (-434/-274) induced GUS expression in extended darkness and conferred down-regulation in extended light. Electrophoretic mobility shift assay (EMSA) and DNase I footprinting assay showed that the DNA binding with one finger box (Dof-box, -341/-338) interacted specifically with leaf nuclear proteins from dark-treated Arabidopsis while GT-1 (-406/-401) binds both dark- and light-treated Arabidopsis, suggesting that Dof and GT-1 motifs are required to mediate circadian regulation of ACBP3. Moreover, GUS staining and fluorometric measurements revealed that a 109 bp region (-543/-434) was responsive to phytohormones and pathogens. Within this 109 bp region, an S-box of AT-rich sequence (-516/-512) was identified to bind nuclear proteins from pathogen-infected Arabidopsis leaves, providing the basis for pathogen-inducible regulation of ACBP3 expression. Hence, three cis-responsive elements (Dof, GT-1 and S-box) in the 5’-flanking region of ACBP3 were demonstrated to participate in the regulation of ACBP3. The regulation of ACBP3 by circadian control is not surprising given that defense genes are now known to be circadian-regulated; infection being anticipated at dawn coinciding with pathogen activity in spore dispersal during the light period. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy