München, Techn. Universiẗat, Diss., 2001.

Neurofilament proteins are intermediate filaments found in the neuronal cytoskeleton. Phosphorylation of these proteins is considered important for the assembly and stability of the filaments. Accurate molecular weights have been difficult to measure, largely because the high degree of phosphorylation results in M[subscript r]'S that are significantly greater than dictated by their putative sequences. Mass spectrometry has now been used to measure the molecular weights of all three bovine neurofilament proteins, NF-L, NF-M and NF-H, which are 62 kDa, 105 kDa and 125 kDa, respectively. Peptide mapping resulted in the elucidation of many phosphorylation sites in NF-L and NF-M. Sixteen serines and four threonines within the C-terminal tail domain of NF-M were found to be phosphorylated. Ten of these are within the lysineserine- proline (KSP) motif, and two are in the variant motif, glutamic acid-serine-proline (ESP). In addition six phosphorylation sites, Ser-136, 163, 241, 242, and Thr-139, and 184 were identified in the rod domain of NF-M. Phosphorylation sites identified in NF-L include four serines in the head domain, and one serine in the C-terminal domain. Digests analyzed by LC-ESI mass spectrometry combined with database searching resulted in 88.5% sequence coverage of NF-M, 79.2% of NF-L and 38.4% of NF-H. Alkylation of NF-L, NF-M, and NF-H using a known neurotoxin, 2,5-hexanedione resulted in complicated spectra due to crosslinked peptides. Presently, software limitations have prevented complete identification of these peptides or alkylation products. / Graduation date: 2003

Zugl.: Magdeburg, Univ., Diss., 2008

The cytokeratins from various human tissue were isolated using chromatographic techniques. The cytokeratins were first extracted from crude tissue using high and low salt buffers. It was necessary to use a denaturing agent such as urea to solubilize the resulting cytokeratin pellet. Imidazole also seemed to help solubilize the pellet and a reducing agent such as 2-Mercaptoethanol was not needed as previously believed. The acidic cytokeratins were separated from the neutral-basic cytokeratins using a DEAE ion-exchange column. The acidic cytokeratin fraction was further separated on a moderately polar reverse phase column with an acetonitrile gradient to eluted the proteins. Tetramethylammonium tetrafluoroborate was added to the mobile phase to react with any unreacted silanol groups on the stationary phase and trifluoroacetic acid was added to ion pair with the protein. The peaks were analyzed for purity using two dimensional electrophoresis and monoclonal antibodies that recognize the cytokeratins.

Regensburg, Univ., Diss., 2007

Thesis (M.S.)--Florida State University, 2006. / Advisor: B. Bryant Chase, Florida State University, College of Arts and Sciences, Dept. of Biological Sciences. Title and description from dissertation home page (viewed June 7, 2006). Document formatted into pages; contains viii, 57 pages. Includes bibliographical references.

No description available.

No description available.

Two aspects of teleost respiration have been emphasised in this investigation. Firstly the gill filaments themselves were observed in order to determine whether or not they played an active role in the ventilation of the gill lamellae. The musculature of the filaments was studied, using visual and electronic methods, and continual muscular activity was noted. Two possible functions of these muscles of the gill filaments have been proposed. Secondly, the brain centres which initiate and maintain the respiratory rhythm were investigated. The neural mechanism was found to be much more complex than had hitherto been suspected in the literature. / Thesis / Doctor of Philosophy (PhD)

No description available.