Multiple Isozymes of Cyclic Nucleotide Phosphodiesterases in the Rat

Lavan, Brian Edward (1990) Multiple Isozymes of Cyclic Nucleotide Phosphodiesterases in the Rat. PhD thesis, University of Glasgow.

Abstract

Cyclic nucleotide phosphodiesterases catalyse the hydrolysis of 3'5'-cyclic nucleotides, such as cyclic AMP and cyclic GMP, to produce 5'-derivatives. Multiple isozymes of this enzyme exist that differ in their substrate specificities, means of regulation and subcellular localisation. The soluble phosphodiesterases present in homogenates of both rat liver and rat hepatocytes have beed identified and characterised. Using a high resolution anion-exchange system (Mono Q) to rapidly separate soluble phosphodiesterases, it has been shown that five separate activities are present in both of these soluble fractions. On this basis, it was concluded that the multiplicity of phosphodiesterase species in liver is not due to the presence of multiple cell types in this organ. These soluble activities were termed PDE MQ-I to PDE MQ-V and were distinguishable from one another by a number of criteria. These included substrate specificity, kinetic properties, sensitivity to Ca2+/Calmodulin or cyclic GMP, dependency on magnesium, sensitivity to a number of reference phosphodiesterase inhibitors, molecular weights and chromatographic properties.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Biochemistry
• Date of Award: 1990
• Depositing User: Enlighten Team
• Unique ID: glathesis:1990-77005
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jan 2020 09:24
• Last Modified: 14 Jan 2020 09:24
• URI: https://theses.gla.ac.uk/id/eprint/77005