Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains viii, 81 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 150-162).

Protein solubility of Pacific whiting muscle with isoelectric point at pH 5.5 was significantly affected by pH. The highest breaking force was measured from fish proteins treated at pH 11, while high deformation values were obtained at pH 2 and 11. Texture of gels made using the conventional method were quite inferior to gels made using fish proteins treated at pH 2 or 11, while color of conventional gels was significantly better than the other treatments. SDS-PAGE revealed that fish proteins were highly denatured during acid or alkali treatment. High cathepsin B-like activity was detected from acid-aided fish proteins. Strong cathepsin L-like activity was found in fish proteins treated at pH 10.5, which corresponded with the lower breaking force and deformation obtained from those samples. Disulfide bonds contributed to high texture value in fish proteins treated at pH 11. Physicochemical characteristics of sarcoplasmic proteins (SP) from rockfish and their interaction with Alaska pollock surimi (myofibrillar proteins) were investigated. Solubility of SP was significantly suppressed at acidic pH (2-4) plus high salt concentration (0.5 M NaCl). This was also supported by SDS-PAGE results (extensively degraded SP). DSC results revealed SP gave three endothermic transitions. The least amount ofproteins was lost when treated at pH 2 or 3 followed by precipitation at pH 5.5. SP did not enhance the gelation properties of myofibrillar proteins, but positively contributed to gelation with myofibrillar proteins when compared to sucrose. Myofibrillar proteins were primary components contributing to heat-induced gelation. Salt effect on acid- or alkali-treated surimi gel was investigated. Good gels were obtained without salt using acid- and alkali-treated fish proteins. Their texture properties decreased as NaCl content increased, unlike conventional surimi gels. Consequently, NaCl did not solubilize myofibrillar proteins once the fish proteins were treated by acid or alkali. Solubility was apparently not a key factor for the texture properties of acid- or alkali-treated surimi. Transglutaminase-mediated setting reaction was partially inactivated during acid or alkaline treatment. Acid-treated surimi gel gave the best color properties. / Graduation date: 2003

by Cai Dong Qing. / "January 2001." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001 / Includes bibliographical references (p. 179-190). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Skeletal muscle proteins are the largest amino acid pool in animal body and are continuously degraded and resynthesized. Dozens of factors have been shown to influence the balance between synthesis and degradation and thereby regulate muscle growth and function. It is now know that one of the major regulatory bases of muscle metabolism is neuron-muscle interaction. A neurogenic factor, ciliary neurotrophic factor (CNTF), is proposed to exert myotrophic actions and could possible be a mediator of neuron-muscle interactions. The goal of this study was to investigate the effects of CNTF on muscle protein turnover in an in vitro system. CNTF was applied to differentiated cultured muscle cells (L8 cell line). Radiochemical labeled amino acids were added to the culture medium to determine the rate of incorporation or release by the cells as indexes of protein synthesis and protein degradation, respectively. Total protein was measured as an index of change in total protein accretion. Twelve hours of CNTF treatment increased myofibrillar protein synthesis by 10%. However, longer CNTF treatment (24 hours) reduced non-myofibrillar protein synthesis. CNTF (1 ng/ml) decreased protein degradation but higher doses (20 ng/ml) accelerated protein degradation. These changes in protein turnover resulted from changes in the myofibrillar protein fraction rather than from changes in turnover of the non-myofibrillar fraction. The change in protein synthesis and protein degradation resulted in an increase in total protein accretion of about 6%. Compared with the myotrophic studies on the effects of CNTF in vivo, the action of CNTF were relatively small. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed that CNTF receptor alpha subunit (CNTFR��) mRNA expression is lower than which is expressed in muscle tissue. This could explain the reason why CNTF exerted smaller effects in vitro compared to those reported in vivo. Overall, CNTF exerts a small but statistically significant anabolic actions in cultured skeletal muscle and the actions were highly dose-dependent. The limited action of CNTF in vitro may be related to its low receptor density in the L8 cell (compared to in vivo). Because actions may be highly dose-dependent, a challenging series of studies are ahead for anyone wishing to identify the signal transduction mechanisms which account for CNTF's actions. / Graduation date: 1998

Thesis (Ph. D.)--York University, 1999. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 135-144). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ39261.

The results of SDS-PAGE and densitometry indicated that a significant amount of myofibrillar proteins was lost during surimi processing. Microfiltration (MF) was utilized to recover insoluble particulate. The MF-recovered proteins showed highly functional properties in gel hardness, cohesiveness, color, and water retention ability. The soluble proteins concentrated by ultrafiltration (UF) possessed dark colors and strong odors. However, the use of UF demonstrated the possibility of recycling water in leaching systems. To reduce the loss of myofibrillar proteins during processing, the factors causing solubilization of myofibrillar proteins were investigated. Myosin and actin were highly soluble when their ionic strengths were substantially reduced. Salt concentrations of 0.25%, 0.5%, and 1.0% NaCl reduced the solubility of myosin and actin but did not remove sarcoplasmic proteins effectively. At 2.0% NaCl, severe loss of myosin, actin, α-tropomyosin, β-tropomyosin, and troponin-T was observed. At low water/meat ratio (2:1) with increased washing cycles and washing time, more sarcoplasmic proteins per unit of water were removed without a noticeable loss of myosin or actin. Myosin heavy chain (MHC) content, water retention ability, and whiteness of the washed mince were comparable to that at high water/meat ratio (4:1). Prolonged storage and elevated temperatures caused a severe proteolysis of myofibrillar proteins. The degraded proteins had higher solubility than their native myofibrillar proteins. MHC and actin degradation both showed a good correlation to protein solubility. The relationship between conformational changes and solubility of myofibrillar proteins was investigated using myosin as a model system. The results showed that adding salt or shifting pH from the isoelectric point of myosin caused an increased surface hydrophobicity and a decreased helix structure. A slightly increased sulfhydryl content was also observed. These conformational changes resulted in an increased solubility. At high salt concentration (>1.0 M), myosin regained its helix structure with a concomitant loss of solubility. The salting out effect was probably due to the dominant hydrophobic interaction among nonpolar amino acids residues. / Graduation date: 1996 / Best scan available. Original is a black and white photocopy.

Thesis (Ph. D.)--York University, 2002. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 160-183). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ82779.

Thesis (Ph. D.)--University of Connecticut, 2005. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph. D.)--University of Connecticut, 2006. / Title on fiche header: Effects of endurance exercise on skeletal muscle protein turnover and intracellular signaling. Includes bibliographical references.