Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 151-164). Also available on the World Wide Web.

Thesis (M.S.) in Biochemistry--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 34-37).

Thesis (Ph. D.)--University of Chicago, 1936. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Includes bibliographical references.

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

The phosphorylation of the Fujinami sarcoma virus transforming protein (FSV P140gag-fps) is complex, reversible and affects its tyrosine specific protein kinase activity and transforming function. The sites of phosphorylation within FSV P140gag-fps have been localized to various regions of the protein using partial proteolysis. The two major phosphotyrosine residues and a major phosphoserine residue are located in the C-terminal portion of the fps region, which contains the kinase active domain. A comparative tryptic phosphopeptide analysis of the gag-fps proteins of three FSV variants shows that the phosphotyrosine containing peptides have similar mobilities. To determine whether tyrosine phosphorylation affects protein function and to evaluate the substrate specificity of the protein kinase intrinsic to FSV P130gag-fps oligonucleotide-directed mutagenesis was used to change tyrosine-1073, the major site of P130gag-fps phosphorylation. Tyrosine-1073 was mutated to a phenylalanine and a glycine, amino acids that cannot be phosphorylated, and to the other commonly phosphorylated hydroxyamino acids, serine and threonine. Neither serine nor threonine were phosphorylated when substituted for tyrosine-1073 indicating a strict specificity for and oncogenic capacities. These data indicate that tyrosine phosphorylation stimulates the biochemical and biological activities of FSV P130gag-fps and suggest that tyrosine phosphorylation modulates protein function. Mutations within the putative ATP-binding site of P130gag-fps at lysine-950 destroy both its kinase and transforming activities, supporting the idea that the tyrosine kinase activity intrinsic to P130gag-fps is essential for its transforming function. The mutant protein was also shown to be phosphorylated at a second tyrosine site, which has been previously identified in wild-type P130gag-fps as a site exclusively phosphorylated in vivo. Phosphorylation of secondary tyrosine residues within a mutant protein devoid of intrinsic tyrosine protein kinase activity suggests that the FSV P130gag-fps may be a target for phosphorylation by cellular tyrosine specific protein kinases. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

No description available.

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

The collagen content and composition of collagens in different age classes of shrimp were determined. Their physical and chemical characteristics were investigated. The interrelationship of shrimp size and muscle collagen content to raw and cooked meat yield was established. Total collagen content for three lots of round shrimp with weights averaging 2.58±.39, 5.27±.55 and 7.72±.96 g was determined to be 2.36, 3.35 and 3.47 mg collagen/g total musculature N, respectively. Unformed collagen comprised 53.85, 35.52 and 0.86% of the total collagen content, respectively. Maturation, as reflected by shrimp size, was accompanied by a near linear increase in formed collagen. A molecular weight of 310,000 for shrimp collagen was determined using SDS gel electrophoresis. The accuracy of this determination was compromised by limited mobility and lack of standard reference proteins of appropriate molecular weight, but did establish a molecular weight in a range common to other collagens. Variations in the amino acid composition of formed and unformed collagen reflected the function of the tissues in the musculature from which they were derived. Formed collagen contained higher amounts of glycine, proline and hydroxylysine than unformed collagen, providing a chemical basis for its structural function in formed connective tissues. Remaining amino acids, except histidine, glutamate and arginine were contained in higher amounts in unformed collagen. Unformed collagen also contained a substantial amount of unidentified components which were suspected to be amino sugar derivatives. Only trace amounts of these components were found in formed collagen. Shrimp collagen contained unusually low levels of glycine, only trace amounts of hydroxyproline and substantial quantities of tryptophan. Glycine and hydroxyproline are important amino acids in mammalian collagens, but tryptophan is usually not present. Shrimp collagen also contained higher levels of threonine, tyrosine, hydroxylysine, valine, methionine, leucine, isoleucine and phenylalanine than most other reported collagens. These variations in amino acid composition seem to reflect a requirement for a structural protein possessing unique characteristics commensurate with the anatomical structure of the species. The yield (% dry wt.) of raw and cooked (100 sec; 101°C in steam) derived through hand peeling round shrimp, was correlated (P>.001) in a positive manner by well defined power functions. Raw meat yield (% dry wt.) declined during ice storage in a linear (P>.001) manner at a rate dependent upon shrimp size. The more rapid loss of solids from large shrimp reduced yield differences as storage was extended. Raw meat losses during ice storage ranged from 0.298 to 0.318 g raw meat dry matter/100 g round shrimp/day for 2.5 and 7.5 g shrimp respectively. Dry matter weight loss from raw meat through the washing action of melting ice, was replaced in a linear (P>.05-P>.005) manner with water to maintain yield (% wet wt.) during storage. Ice storage expanded cooked yield (% dry wt.) differences between shrimp sizes. Meat losses through cooking mediated by ice storage, ranged from 0.421 to 0.303 g cooked meat dry matter/100 g round shrimp/day for 2.5 and 7.5 g shrimp, respectively. The age class dependent content and composition of collagens in the musculature of shrimp was reflected in the recovery of raw and cooked meat. Meat from small shrimp contained higher levels of unformed collagen which possessed less dry matter and degraded more rapidly in ice storage. Proteolytic action on elevated levels of unformed collagen was not reflected in the rate of ice storage losses. But, it markedly increased heat induced solubilization of solids and enhanced moisture retention through steam precooking over larger shrimp. Maturation of shrimp associated with more formed and less unformed collagen reduced solids solubilization and moisture retention through steam precooking. / Graduation date: 1982

The purpose of this study was to extract proteins from lentils for use in bread making to improve nutritional quality of bread. Three solvents, distilled water, 0.7 M NaCl and 0.05 M NaOH solutions, were used for extraction. Extractions were done at an alkaline pH near 10 for 30 min. Proteins were recovered by acid precipitation using 1 N HCl. Macro-Kjeldahl determinations were run on the precipitated material to determine protein content. The results showed that extractions were effective using either distilled water adjusted to pH 10.0 or 0.05 M NaOH. Protein recoveries of 66.01-68.79% and 64.01-66.62% were obtained by these two procedures respectively. These are simple methods that do not require sophisticated equipment. Thus they would be practical and economical for use on a large scale. For bread supplementation studies, lentil proteins were extracted by distilled water with pH of the slurries adjusted to pH near 10. The extracted lentil proteins were used to replace white wheat flour at levels of 0, 5, 7.5 and 10% on a dry weight basis. Breads were made using the the straight dough method. Sodium-stearoyl-2-lactylate was used as a dough conditioner. Specific volume, color, texture and protein content of the breads were evaluated objectively. The breads were also subjected to sensory evaluation for color, texture, moistness, flavor and overall desirability. Specific volume decreased as the level of lentil protein increased. The control bread had the highest specific volume which was significantly higher (p < 0.05) than the lentil supplemented breads. Bread crumb became darker in color with increasing lentil protein levels as shown by a decrease in Hunter L values. Hunter 'a' values increased in breads with higher lentil protein contents but there was little change in Hunter 'b' values. Lentil proteins resulted in a decrease in crumb compressibility. There was a linear relation between levels of protein replacement and protein contents of the breads. The 5%, 7.5% and 10% lentil protein replacements increased the protein contents of the breads from 11.44% to 13.-2%, 13.80% and 14.59% respectively. Although the lentil breads received lower sensory evaluation scores than the control breads, they were judged as acceptable at the 5%, 7.5% and 10% substitution levels. These findings are significant because the supplemented breads have higher nutritional value. This would help reduce nutritional deficiency problems especially in areas where protein malnutrition exists. / Graduation date: 1983

The influence of polyphosphates upon the emulsification of enzymatic hydrolyzates of casein and lactalbumin and upon salt-soluble meat proteins was determined by a model system in which oil-in-water emulsions were formed. Sodium acid pyrophosphate, sodium tripolyphosphate and sodium hexametaphosphate were mixed together in a weight ratio of 4:2:4, respectively, to form a polyphosphate blend. This blend was added at a level of 0.5% (w/v) to casein or lactalbumin dissolved in 3% NaCl, pH 6.0. The polyphosphate blend was also added at the above level to meat proteins solubilized in 3% NaCl, pH 5.7. Emulsified volume (EV), total g of oil emulsified per 25 ml of protein solution, was determined for the above proteins with or without polyphosphates at varying protein concentrations. Data were also graphically expressed as emulsifying capacity (EC) and oil phase volume (OPV). For all proteins studied with or without polyphosphates, EV and OPV values increased with increasing protein concentration whereas EC values decreased. Addition of the polyphosphate blend to casein solutions containing protein levels in excess of 2 mg/ml resulted in significantly (P<0.01) higher EV levels than those of the controls. Conversely, the EV values of the polyphosphate-treated lactalbumin solutions were significantly (P< 0.01) lower than those of the controls at all protein levels tested. The diverse data obtained with these two proteins appear to be related to variations in molecular size and shape and to differences in the manner in which the proteinphosphate interactions occurred to cause the polyphosphates to enhance the emulsification of casein while depressing that of lactalbumin. Addition of the polyphosphate blend had little or no effect upon the emulsification of meat protein extracts obtained from fresh, frozen or refrozen samples. Thus, it was concluded that the polyphosphate blend did not modify nor exert any detectable influence upon the emulsification of solubilized meat proteins as tested in a model system. / Graduation date: 1975