Speaker
Description
Lipolysis, also called lipid hydrolysis, is a life-essential biochemical process that releases fatty acids and glycerols stored in the form of water-insoluble triglycerides within lipid droplets of specialised cells known as adipocytes. The enzyme adipose triglyceride lipase (ATGL) is believed to be the rate-limiting and key regulator of lipolysis. However, recent studies show that besides lipolysis, it also catalyses in parallel a transacylation reaction of two diglycerides, the first downstream product of lipolysis of triglycerides, to produce one triglyceride and one monoglyceride molecule.
All previous mathematical modelling approaches that describe the lipolytic and transacylase activities of ATGL have used the Michaelis-Menten and mass-action-law as reaction rates, which can only be considered as approximative models with unknown accuracy as ATGL catalyses both lipolysis and transacylation on the same active site.
In this talk, we therefore derive kinetic models that describe both the lipolytic and transacylase activities of ATGL in a single system, which we base on the hypothesised molecular mechanisms of lipolysis and transacylation. We present two chemical reaction networks and derive quasi-steady-state-approximative systems. In addition, we present a first PDE modelling approach which considers that the enzymes act on or near the surface and thus, lipolysis and transacylation are localised. Finally, we provide simulations as well as parameter estimations.
