Thylakoid Membranes and Pancreatic Lipase/Colipase

Abstract: Obesity is a major health problem in the world that increases the occurrence of type-2 diabetes and cardiovascular disease. The reason for obesity is a dysfunction in the regulation of energy balance. It has been shown that dietary fat induces satiety as long as this nutrient stays in the intestine. One important gastrointestinal satiety signal is cholecystokinin (CCK), released from the intestine by the entry of dietary fat and protein. The enzyme responsible for the main intestinal fat digestion is pancreatic lipase and its cofactor colipase. We have found that thylakoid membranes inhibit the activity of pancreatic lipase/colipase in vitro. Two mechanisms are suggested for this inhibition; 1) adsorption of the lipase/colipase to the thylakoid membranes, supported by binding experiments and 2) adsorption of the thylakoid membranes on the lipid droplets, supported by electron microscopy pictures. In both mechanisms access of the lipase/colipase complex to the lipid substrate is hindered. We have also found that thylakoid membranes induce satiety, increase cholecystokinin (CCK), and reduce as well serum triglycerides as insulin in human and animal models. In addition, thylakoid membranes were remarkably resistant towards the proteases pepsin, trypsin as well as towards whole gastric and pancreatic juice. Thus, thylakoid membranes have a potential as a food additive for preparation of food with health promoting properties.