The Study Of Recognition Between Bovine Trypsin And Flavonoid Drugs

Serum albuminand trypsin are two kind of important proteins in human body.Serum albumin exists widely in the plasma,playing an important and irreplaceable role as the carrier for a variety of life activities.Trypsin is an important digestive enzyme.Food and many drugs require the participation of trypsin for degradation and bio-utilization.The study of the interaction between protein and small molecular drugs is useful for understanding the metabolism of drugs in vivo,the transport and the clinical application of drugs and the development of new drugs.In this paper,the combination of fluorescence spectroscopy and molecular docking is adopted to study the recognition of serum albumins and bovine trypsin with several small molecule flavonoid drug.(1)The interaction between bovine serum albumin(BSA)or human serum albumin(HSA)and hesperidin and diosmetin was studied by fluorescence spectroscopy and molecular docking under simulated physiological conditions.Fluorescence data indicate that the quenching between protein and quencher is static quenching.Drug and protein can form a 1: 1 type complex.The results of molecular docking show that hydrogen bonding and hydrophobic interactions are the main driving forces for the quenching of BSA / HSA by hesperidin and diosmetin.(2)The interaction between trypsin and formononetin,biochanin A,5-methyl-7-methoxyisoflavone was studied by fluorescence spectroscopy and molecular docking.The analysis of the fluorescence data shows that the fluorescence emission of the protein quenched by the quencher is based on the static quenching mechanism.The binding constants of the complexes are 6.3 × 10~4,2.1 8 × 10~4 and 1.58 × 10~3,respectively,and the binding numbers are 1.12,1.00,0.95,respectively.The types of interactions between the three drugs and the trypsin complex include aromatic ring piling,hydrophobic interaction and hydrogen bonding.(3)The interaction between scutellarin and trypsin was studied by fluorescence spectroscopy combined with molecular docking method.The analysis of the fluorescence data shows that the fluorescence emission of the protein is quenched by the quencher is based on the static quenching mechanism.The binding constant of the complex is 1.58 × 10~3 and the number of binding number is 0.87.It can be seen that the complex formed by the host and guest is at a 1: 1 ratio.(4)The interaction between icariin and trypsin was studied by fluorescence spectroscopy and molecular docking under simulated physiological conditions.Icariin quenches trypsin fluorescence emission at the static mechanism.The binding constant is 1.99 × 10~5 and the binding number n is 1.14.The complex is formed at a 1: 1 ratio as well.