Browsing by Author "Van Dyk, Jacobus Barend"

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    A detailed kinetic and mechanistic investigation of the multi-step oxidation of [PtIICl4]2- by [IrIVCl6]2- in acidic medium
    (Stellenbosch : Stellenbosch University, 2013-12) Van Dyk, Jacobus Barend; Gerber, Wilhelmus J.; Koch, Klaus R.; Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science.
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    Mathematical modelling of glycolysis in skeletal muscle cells
    (Stellenbosch : Stellenbosch University, 2020-04) Van Dyk, Jacobus Barend; Snoep, Jacob Leendert; Van Niekerk, David Douglas; Stellenbosch University. Faculty of Science. Dept. of Biochemistry.
    ENGLISH ABSTRACT: Diabetes is a term used to describe a group of metabolic diseases characterised by high blood glucose levels. Regulation of blood glucose levels is facilitated by the insulin stimulation of target tissues, such as skeletal muscle tissue and fat cells. A decrease in the effective working of insulin on target tissues can lead to a variety of symptoms, including damage or dysfunction of organs, such as the eyes, kidneys, nerves, and the heart and ultimately leads to the development of type 2 diabetes. Blood glucose homeostasis is predominately regulated by the metabolic activity of skeletal muscle fibres (70 – 80%). Therefore, there is an interest to investigate the dysfunctions caused by insulin resistance in skeletal muscle cells. In this thesis we present the kinetic characterisation of the glycolytic enzymes in C2C12 skeletal muscle fibres. The kinetic rate equations, describing the dynamic behaviour of each enzyme, was compiled into a kinetic model. The development of a novel HPLC analytical technique for the separation and quantification of glycolytic intermediates and cofactors was also presented in the thesis. This HPLC technique enables the separation and quantification of the glycolytic cofactors; ATP, ADP, AMP, NAD+ and NADH via UV/Vis detection, along with the separation and quantification of 13 glycolytic species derived from glucose, including ACA and ETOH, as well as GLY and G3P via the use and detection of 14C-radioactive labelling. The novel HPLC technique was used to validate the kinetic model describing glycolysis in C2C12 skeletal muscle cells by comparing model simulations to experimental data. 3 incubations of C2C12 skeletal muscle extract was analysed under different concentrations of GLC, FBP, ATP and NAD+ via the HPLC technique and compared to the corresponding model simulations. A good comparison between experimental data and model simulations was obtained, validating the glycolytic model describing glycolysis in C2C12 skeletal muscle extract. Metabolic control analysis was performed on the validated model and showed that the majority of flux control was held by the demand for ATP, described by the ATPase reaction (99.4%). This is in comparison with what is found in literature.