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Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso
Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso
Digitized Theses
Sex hormone-binding globulin (SHBG) is a homodimeric glycoprotein that transports sex steroids in the blood and extravascular fluids, such as seminiferous tubule fluid, where it is often referred to as androgen-binding protein (ABP). A cDNA for the human SHBG precursor polypeptide was expressed in mammalian cell lines. Recombinant human SHBG bound steroids with the same affinity and specificity as natural SHBG, and was immunologically indistinguishable from its natural counterpart. Site-directed mutagenesis of the SHBG cDNA was used to introduce amino acid substitutions that selectively removed glycosylation sites from SHBG. Analysis of these glycosylation mutants demonstrated that carbohydrates are not involved …
Genome Organization, Replication And Movement Of Foxtail Mosaic Virus, Michele Rouleau
Genome Organization, Replication And Movement Of Foxtail Mosaic Virus, Michele Rouleau
Digitized Theses
Foxtail mosaic virus (FMV) is a member of the potexvirus family which infects primarily monocotyledonous plants. Its flexuous filamentous particles are 500 nm long and consist of a messenger sense RNA encapsidated by a single type of coat protein. We have determined the nucleotide sequence of the FMV gRNA as well as the organization of its coding sequences. The gRNA is 6151 nucleotides long and contains five major open reading frames (ORF). The amino acid sequences of the putative proteins are closely related to homologous proteins of other sequenced potexviruses.;A procedure for the partial purification of the RNA-dependent RNA polymerase …
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
Digitized Theses
Bacteriophage Mu is one of the model systems to study DNA transposition. The availability of an in vitro soluble system greatly facilitates the dissection of the transposition mechanisms at the molecular levels. Several aspects of the in vitro mini-Mu DNA transposition have been dealt with in this thesis.;First, the flanking host DNA sequences on the strand cleavage step mediated by Mu transposase (Mu A protein) was investigated. We found that certain flanking host sequences could inhibit the strand cleavage step without affecting the earlier synapsis step. Furthermore, this cleavage defect could be overcome by the Mu B protein in the …
Characterization Of Fungal Fimbriae, Martina Celerin
Characterization Of Fungal Fimbriae, Martina Celerin
Digitized Theses
Fungal fimbriae are surface appendages that were first described by Poon and Day (1974) on the haploid cells of Microbotryum violaceum. They are long (1 to 20 {dollar}\mu{dollar}m), narrow (7 nm) flexuous fibres that were implicated in important cellular functions such as mating and pathogenesis. Since this initial description, numerous other fungi from all five phyla have been shown to produce fimbriae on their extracellular surfaces. Because they are easy to purify, the fimbriae from M. violaceum have been investigated most extensively. The present study extends the earlier characterizations of M. violaceum fimbriae, and expands on the biochemical description of …
Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen
Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen
Digitized Theses
The ornithine urea cycle enzymes, carbamyl phosphate synthetase (CPS-1), ornithine transcarbamylase (OTC) and arginase, are liver-specific proteins. Their expression is coordinately activated during the metamorphosis of the Rana catesbeiana tadpole by thyroid hormone (TH), and their presence is critical for the shift of this amphibian from an aquatic, ammonotelic larva into a terrestrial, ureotelic adult. My studies were focused on analyzing the transcriptional regulation of the genes encoding these urea cycle enzymes and determining whether these genes were upregulated directly or indirectly by TH. With this thought in mind, I isolated and characterized the sequences in the promoter regions of …
The Putative Role Of Fatty Acids In The Activation Of Trehalose Synthesis In The Fat Body Of The Cockroach Periplaneta Americana L, Irshad Ali
Digitized Theses
Hypertrehalosemic hormones produced by the corpus cardiacum increase the concentration of several fatty acids in cockroach fat body trophocytes. The phospholipase A{dollar}\sb2{dollar} (PLA{dollar}\sb2){dollar} activator melittin has a similar effect. The fatty acids include palmitic, stearic, oleic and linoleic acid. The hormone mediated release of these fatty acids is blocked by the PLA{dollar}\sb2{dollar} inhibitors mepacrine and {dollar}\rho{dollar}-bromophenacyl bromide. These observations suggest that hormonal release of fatty acids, may be due to the activation of PLA{dollar}\sb2.{dollar};The increase in non-esterified fatty acids appears to be linked to the increase in trehalose efflux since sugar efflux is stimulated by stearic, oleic, linoleic and arachidonic …
The Regulation Of A Type Iv Phosphodiesterase From L6 Myoblasts, A Thomas Kovala
The Regulation Of A Type Iv Phosphodiesterase From L6 Myoblasts, A Thomas Kovala
Digitized Theses
A potential role for cAMP in regulating the differentiation of myoblasts has lead to the examination of the components of the cAMP signalling system, in this case a cyclic nucleotide phosphodiesterase (PDE). A Type IV PDE isozyme was identified in L6 myoblasts using consensus sequence PCR primers, and its regulation by cAMP studied. Sequencing of RT-PCR products showed the presence of a Type IV PDE mRNA known as ratPDE 3.1. High levels of cAMP induced dramatic increases in the PDE mRNA levels as demonstrated by northern blot analysis. Run-off transcription experiments showed increased rates of transcription. L6 myoblasts which had …
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Digitized Theses
Skeletal muscle consists of multinucleated fibres which are classified as slow (I) or fast (IIA, IIB, IIX) muscle fibre types which differ in their contractile properties and their expression of contractile protein isoforms. Individual muscles contain characteristic distributions of fibre types which can be identified based on their myosin heavy chain (MyHC) content. While classical studies have demonstrated that the fibre type composition of adult muscles can be altered by extrinsic factors (such as changes in the pattern of innervation), recent studies suggest that different fibre types may be formed from distinct myoblast lineages. The purpose of this study was …