The dark blue pigment from Vaccinium bracteatum Thunb.leaves(VBTL)is a healthy ingredient for controlling postprandial blood glucose during the stage of dietary carbohydrate digestion.Our previous study has proved tha...The dark blue pigment from Vaccinium bracteatum Thunb.leaves(VBTL)is a healthy ingredient for controlling postprandial blood glucose during the stage of dietary carbohydrate digestion.Our previous study has proved that the dark blue pigment has an inhibition effect on pancreaticα-amylase.However,the influence on other digestive enzymes(α-glucosidases,trypsin,andα-chymotrypsin)is still unclear.Therefore,this research evaluated the impact of this dark blue pigment on the three digestive enzymes during in-vitro digestion.The effects of dark blue pigment on the activities and conformations of theα-glucosidase,trypsin,andα-chymotrypsin were confirmed by multi-spectroscopic techniques and molecular docking.The results showed that this pigment possessed a higher inhibition ability on theα-glucosidase.The complexes of three enzymes and the pigment all resulted in the changes in fluorescence quenching and secondary structures of these complexes.However,the interactions between two proteolytic enzymes and pigment slightly impacted their activities.Additionally,molecular docking suggested that the complex betweenα-glucosidase and pigment formed hydrogen bonds and hydrophobic interactions in the substrate-binding pocket.These findings provide creative insight into the VBTL dark blue pigment controlling postprandial hyperglycemia without side effects on the proteolytic enzymes.展开更多
基金supported by the National Natural Science Foundation of China(32072254)the China Postdoctoral Science Foundation(2021M701462)+3 种基金the Postdoctoral Research Funding Program of Jiangsu Province(2021K097A)the Fundamental Research Funds for the Central Universities(JUSRP121106)Research and Development Program of Tianchang(TZY202002)the"Qing Lan Project"of Jiangsu Province.The authors declare no competing financial interest.
文摘The dark blue pigment from Vaccinium bracteatum Thunb.leaves(VBTL)is a healthy ingredient for controlling postprandial blood glucose during the stage of dietary carbohydrate digestion.Our previous study has proved that the dark blue pigment has an inhibition effect on pancreaticα-amylase.However,the influence on other digestive enzymes(α-glucosidases,trypsin,andα-chymotrypsin)is still unclear.Therefore,this research evaluated the impact of this dark blue pigment on the three digestive enzymes during in-vitro digestion.The effects of dark blue pigment on the activities and conformations of theα-glucosidase,trypsin,andα-chymotrypsin were confirmed by multi-spectroscopic techniques and molecular docking.The results showed that this pigment possessed a higher inhibition ability on theα-glucosidase.The complexes of three enzymes and the pigment all resulted in the changes in fluorescence quenching and secondary structures of these complexes.However,the interactions between two proteolytic enzymes and pigment slightly impacted their activities.Additionally,molecular docking suggested that the complex betweenα-glucosidase and pigment formed hydrogen bonds and hydrophobic interactions in the substrate-binding pocket.These findings provide creative insight into the VBTL dark blue pigment controlling postprandial hyperglycemia without side effects on the proteolytic enzymes.
