• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • Tagged with
  • 25
  • 25
  • 10
  • 9
  • 6
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Studies on the N-O-acyl shift in proteins and on its application to the cleavage of peptide bonds

Lichti, Frieda Ulrike, January 1961 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [54]-56).
2

Studies on protein structure and a new method of selective degradation of peptides

Thakur, Vatsala Narayanrao, January 1959 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Abstracted in Dissertation abstracts, v. 19 (1959) no. 12, p. 3116. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
3

Allocation of the free amino groups in proteins and peptides

Gurin, Samuel, January 1934 (has links)
Thesis (Ph. D.)--Columbia University, 1934. / Vita. Bibliography: p. 24-25.
4

Advances in capillary electrophoresis analysis of lipids, proteins, and peptides with laser-induced fluorescence /

Zhang, Le. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 165-175).
5

Studies of protein denaturation and aggregation

Wilkins, Deborah K. January 1999 (has links)
No description available.
6

Elucidating the early events of protein aggregation using biophysical techniques

Cole, Harriet Lucy January 2013 (has links)
Proteins and peptides can convert from their native form into insoluble highly ordered fibrillar aggregates, known as amyloid fibrils. The process of fibrillogenesis is implicated in the pathogenic mechanisms of many diseases and, although mature fibrils are well characterised by a plethora of biophysical techniques, the initiation and early steps remain, to date, ambiguous. Mass spectrometry can provide invaluable insights into these early events as it can identify the low populated and transient oligomeric species present in the lag phase by their mass to charge ratio. Recent evidence has shown that oligomers formed early in the aggregation process are cytotoxic and may additionally be central to the progression of diseases associated with amyloid fibril presence. The hybrid technique of ion mobility mass spectrometry can be employed to provide conformational details of monomeric and multimeric species present and elucidate the presence of oligomers which possess coincident mass to charge ratios. Molecular modelling, in conjunction with experimental results, can suggest probable monomeric and oligomeric structural arrangements. In this thesis three aggregating systems are investigated: amyloidogenic transthyretin fragment (105-115), insulin and two Aβ peptides. Initially amyloidogenic endecapeptide transthyretin (105-115) is studied as it has been widely utilised as a model system for investigating amyloid formation due to its small size. Secondly insulin, a key hormone in metabolic processes, is investigated as extensive research has been carried out into its aggregation into amyloid fibrils. The formation of insulin amyloid fibrils rarely occurs in vivo; however localised amyloidosis at the site of injection and the aggregation of pharmaceutical insulin stocks present problems. Thirdly the aggregation of A β peptides Aβ (1-40) and Aβ (1-42) and their interactions with an aggregation inhibitor, RI-OR2, are characterised. A (1-42), although less commonly produced in vivo, is more cytotoxic and has a faster aggregation mechanism than Aβ (1-40). Both Aβ peptides are implicated in the aetiology of Alzheimer’s disease whilst RI-OR2 has been reported to prevent the production of high molecular weight oligomers, with particular suppression of Aβ (1-42) aggregation.
7

Factors determining the cytotoxic nature of pathogenic amyloid proteins

Vadukul, Devkee M. January 2018 (has links)
No description available.
8

Cytocidal activity of Cry41Aa, an anticancer toxin from Bacillus thuringiensis

Souissi, Wided January 2018 (has links)
Bacillus thuringiensis (Bt) is a gram positive spore forming bacterium which produces intracellular protein crystals toxic to a wide variety of insect larvae and is the most commonly used biological pesticide worldwide. More recently, Bt crystal proteins known as parasporins have been discovered, that have no known insecticidal activity but target some human cancer cells exhibiting strong cytocidal activities with different toxicity spectra and varied activity levels. Amongst these parasporins, parasporin-3 most closely resembles the commercially used insecticidal toxins and presents the narrowest activity spectrum, showing moderate cytotoxicity against only two cancer cell lines, HL-60 (Human promyelocytic leukemia cells) and HepG2 (Human liver cancer cells). Parasporin-3, also called Cry41Aa, has only been shown to exhibit cytocidal activity towards these two cell lines after being proteolytically cleaved. In order to understand this activation mechanism various mutations were made at the N- or C-terminal region of the protein and the toxicity against both HepG2 and HL-60 cell lines was evaluated. Our results indicate that only N-terminal cleavage is required for activation and that N-terminally deleted mutants show some toxicity without the need for proteolytic activation. Furthermore we have shown that the level of toxicity towards the two cell lines depends on the protease used to activate the toxin. Proteinase K-activated toxin was significantly more toxic towards HepG2 and HL-60 than trypsin-activated toxin. N-terminal sequencing of activated toxins showed that this difference in toxicity is associated with a difference of just two amino acids (serine and alanine at positions 59 and 60 respectively) which we hypothesize occlude a binding motif. Preliminary work carried out on binding showed a lack of correlation between binding and toxicity since toxin binds to both susceptible and non-susceptible cancer cell lines. In an attempt to better understand the mechanism of action of Cry41Aa against these cells, we evolved resistance in HepG2 through repeated exposure to increasing doses of the toxin. Morphological, physiological and genetic characteristics of the resistant cell line were compared with susceptible cells. Toxin was shown to bind to resistant HepG2 similarly to the susceptible line. RNA sequencing identified AQP9 as a potential mediator of resistance but extensive investigations failed to show a direct link. The involvement of certain intracellular signalling pathways were also investigated in order to understand cell responses to the toxin and showed that in response to the toxin p38, but not ERK1/2, is activated and in a dose dependent manner.
9

Neuron-ligand pathfinding on surfaces modified by laminin and laminin-derived peptides

Leng, Ying. January 2006 (has links)
Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Thomas P. Beebe, Jr., Dept. of Chemistry & Biochemistry. Includes bibliographical references.
10

The preparation of a metalloporphyrin-peptide conjugate artificial protein for the catalytic oxidation of alkenes /

Geier, George Richard. January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (p. [201]-216).

Page generated in 0.0678 seconds