Inhibitory effect of Auricularia auricula polysaccharides on pancreatic lipase activity

Objective:The inhibitory effect of Auricularia auricula polysaccharides on the activity of pancreatic lipase was investigated.4-nitrophenyl laurate was used as a substrate.To screening optimum conditions of Auricularia auricula polysaccharides inhibited of the pancreatic lipaseactivity, the types of inhibition and inhibition of constant.Methods:Auricularia auricula polysaccharides were obtained through hot water extraction and alcohol precipitation.Polysaccharides were separated by anion exchange resin.The effects of Auricularia auricula polysaccharides were studied under different conditions (concentrate, p H, temperature, time) on pancreatic lipase activity.The relation between Auricularia auricular polysaccharides and conformation of pancreatic lipase were researched through ultraviolet absorption spectrometry.The reaction mechanism of between Auricularia auricula polysaccharides and pancreatic lipase through testing absorbance values was ensured when added different concentrate substrates.Results:Six components were obtained, and the neutral polysaccharide had the best suppression effect.When the p H was 7.5, temperature was 37℃, and time was 60 minutes, the inhibition rate reached the maximum value46.93%.And the reaction was a noncompetitive inhibition.The Michaelis constant was 17.68 mg/m L.The maximum reaction rate was 1.43μmol/min.The Ki was 30.32 mg/m L.By ultraviolet absorption spectrometry it showed that pancreatic lipase maximum absorption wavelength ultraviolet absorption spectrum redshift, which meant the Auricularia auricula polysaccharide changed the conformation of pancreatic lipase, leading to the restriction of enzyme catalytic activity.Conclusion:Auricularia auricula polysaccharides had suppression effect on pancreatic lipase activity.It indicated that the antihyperlipidemic effect of Auricularia auricula polysaccharide was related with the inhibiton of the activity of pancreatic lipase, which lay a theoretical foundation for the development of the functional products of reducing blood lipid.