Other Medicine and Health Sciences Commons^™

Identification Of Ligand-Receptor Interactions Between Saccharomyces Cerevisiae Α-Factor Pheromone Receptor (Ste2p) And Its Tridecapeptide Ligand, Çağdaş Devrim Son

Doctoral Dissertations

G protein-coupled receptors (GPCRs) are a class of integral membrane receptor proteins that are characterized by a signature seven-transmembrane (7TM) configuration. These receptors comprise a large and diverse gene family found in fungi, plants, and the animal kingdom. Recent studies with GPCRs have begun to elucidate their importance in many physiological processes, thus various human diseases are associated with GPCR pathology. Although the overall 3D structure of these receptors carry similar features, binding of an extraordinarily diverse array of ligands trigger many different biological pathways.

The α-factor receptor (Ste2p) of Saccharomyces cerevisiae belongs to the GPCR family. Upon the α-factor …

Respiratory, Cardiovascular And Abdominal Anatomy Of The Ringed Seal (Phoca Hispida), Hrvoje Smodlaka

Doctoral Dissertations

This study investigated the anatomy the ringed seal (Phoca hispida) cardiovascular system (heart and large vessels) and lower respiratory tract (lung), as well as the topographic anatomy of the seal abdomen.

The ringed seal heart is dorsoventrally flattened, with each ventricle residing on its respective side within the thoracic cage. The heart lies horizontal, parallel to the sternum. The right ventricle is long, spacious and thin walled. The right coronary artery continues as the subsinuosal interventricular branch, making it different from domestic carnivores.

The aortic bulb is a large structure in comparison to the equivalent structure in terrestrial mammals, which …

Contributions Of Q67 And Y69 Residues To Ligand Binding And Catalysis In R67 Dihydrofolate Reductase, Lori Gail Stinnett

Doctoral Dissertations

Dihydrofolate reductase (DHFR) serves an important role in metabolism by reducing dihydrofolate (DHF) to the product tetrahydrofolate via hydride transfer from NADPH. R67 DHFR, a plasmid encoded form of the enzyme which provides resistance to trimethoprim, functions as a homotetramer with D_{2 symmetry. Both ligands, DHF and NADPH, interact within a 25 Ǻ active site pore. Mutagenesis of one active site residue results in four-symmetry related mutations causing large effects on binding and catalysis. A construct containing four copies of the DNA for R67 DHFR ligated in-frame and flanked by unique restriction sites was engineered and asymmetric mutants were …}