Antibacterial Mechanism Of Half-fin Anchovy Antibacterial Peptides Maillard Products And Its Effect On Immune Function In Mice

Half-fin anchovy(Setipinna taty)is nutritious,delicious and cheap.But the Half-fin anchovy is small.The utilization rate of half-fin anchovy,both edible and processing,is low.In the previous research,half-fin anchovy antibacterial peptides prepared by protease hydrolysis have strong antibacterial effect,but the smell of fish is heavy.And then through the Maillard reaction to improve the flavor of half-fin anchovy antibacterial peptides.At the same time,it was found that half-fin anchovy antibacterial peptide of Maillard reaction products had strong antibacterial activity.Therefore,On the basis of previous research,this paper also uses the half-fin anchovy protein antibacterial peptides of Maillard reaction products as study object to study the antibacterial effect and effective antimicrobial components of half-fin anchovy antibacterial peptide of Maillard reaction products.and explore its application in immune enhancement.Major studies include:(1)antibacterial model of half-fin anchovy antibacterial peptide of Maillard reaction products;(2)isolation and purification of antibacterial peptides from half-fin anchovy antibacterial peptide of Maillard reaction products;(3)effects of half-fin anchovy antibacterial peptide of Maillard reaction products on immune function in mice.Half-fin anchovy antibacterial hydrolysates-glucose Maillard reaction products react with E.coli.The ultrastructural of the cells were observed by scanning electron microscopy(SEM),membrane permeation,analysis of intracellular enzyme release and changes of particle size after artificial liposomes and half-fin anchovy antibacterial peptide of Maillard reaction products were measured by Malvern potentiometer.Results indicate that: half-fin anchovy antibacterial peptide of Maillard reaction products react with E.coli on 1h,half-fin anchovy antibacterial peptide of Maillard reaction products can induces the membrane permeation,adventitia and intima permeability increased After 5 h,theintracellular lactate dehydrogenase release increased and the ATP content was significantly reduced.The average particle size increased from 170 nm to 230 nm after the interaction between the artificial lipid membrane and half-fin anchovy antibacterial peptide of Maillard reaction products,indicating that half-fin anchovy antibacterial peptide of Maillard reaction products have a synergistic effect on the cell membrane.From the above experimental results that half-fin anchovy antibacterial peptide of Maillard reaction products can reach the surface of the cell through adsorption,causing cell aggregation,and then through the membrane damage to increase the outer membrane and endometrial permeability,resulting in intracellular material leakage,so as to achieve bacteriostatic effect.Half-fin anchovy antibacterial peptide of Maillard reaction products is isolated through different chromatographic methods,including ion exchange chromatography,molecular sieve separation and RP-HPLC.Then,seven antimicrobial peptides were isolated and identified by LC-ESI-MS which were RVAPEEHPTL,WLPVVR,FFTQATDLLSR,VLLLWR,VLLVLLR,VLLALWR and LLSWYDNEFGYSNR.5 of these peptides(peptide 1 RVAPEEHPTL,peptide2 WLPVVR,peptide 3 VLLLWR,peptide 4 VLLVLLR and peptide 5 VLLALWR)were prepared by chemical synthesis.The antibacterial results showed that the other four peptides had antibacterial activity against E.coli except peptide 4.Peptide 2(WLPVVR)was chosen as the starting peptide to synthesize the peptide2-1(WLPVVH),peptide 2-2(WLPVVE)and peptide 2-3(LPVVR).The bacteriostatic results showed that similar peptides of peptide 2 have antibacterial effect,but the antibacterial activity was changed in different degree,which indicated that the peptide sequence composition had an effect on the antibacterial activity.Kunming mice as the object.Through animal experiments on thymus index and spleen index were determined.At the same time,the serum and liver homogenate of mice GSH-Px,T-SOD,CAT,the content of LPO and GSH.Resultsshow: compared with the control group,the effect of half-fin anchovy antibacterial peptide of Maillard reaction products on the thymus index and spleen index was not significant.The high dose of half-fin anchovy antibacterial peptide of Maillard reaction products is helpful to increase the activity of GSH-Px in mice.High dose of half-fin anchovy antibacterial peptide of Maillard reaction products can also increase the activity of T-SOD in liver of mice.The effect of half-fin anchovy antibacterial peptide of Maillard reaction products on the LPO and GSH in mice is very obvious.Judging from the results of each index,half-fin anchovy antibacterial peptide of Maillard reaction products can improve the antioxidant capacity of mice.