In this study, simulated digestion in vitro and chamber model were adopted to evaluate the ferrous iron-chelating capacity and iron absorption facilitation of Ejiao. The iron chelating ability of Ejiao increased by 16.22-fold after gastrointestinal digestion, with enhanced apparent permeability to improve iron absorption. After targeted isolation of Ejiao hydrolysates with iron chelating on immobilized metal affinity chromatography (IMAC), the Ejiao peptide-iron chelates were characterized by HPLC for molecular weight distribution and amino acid composition, LC-MS/MS for peptide sequences, fluorescence, and Fourier transform infrared spectroscopic analyses, scanning electron microscopy (SEM) analysis for structural and physical properties. The results demonstrated that Ejiao peptides chelated with ferrous iron mainly attributed to peptides with molecular weight ranging from 180-2 000 Da (70.51%). Four high-intensity peptides were sequenced as GPAGPIGPV, LQGMPGERG, AGPPGADGQPGAK and LRGPRGDQGPVGRA. The increased carboxylic and amino groups from acidic and basic amino acids in Ejiao peptide composition afforded more sites for iron chelation. The iron chelation aggregated to form larger particles. This study supports peptide-iron chelates formed during digestion to be one of the bioactive components of Ejiao and indicates the promotion of ferrous iron absorption as a potential hematopoietic mechanism of Ejiao.
[1] ABBASPOUR N, HURRELL R, KELISHADI R.Review on iron and its importance for human health[J].Journal of Research in Medical Sciences, 2014, 19(2):164-174.
[2] 管玲娟, 曹丛丛, 屠飘涵, 等.缺铁对肠道免疫功能的影响及新型补铁剂的研究进展[J].食品与发酵工业, 2020, 46(19):264-270.
GUAN L J, CAO C C, TU P H, et al.Research progress of the effect of iron deficiency on intestinal immune function and new iron supplements[J].Food and Fermentation Industries, 2020, 46(19):264-270.
[3] WU W F, YANG Y Y, SUN N, et al.Food protein-derived iron-chelating peptides:The binding mode and promotive effects of iron bioavailability[J].Food Research International, 2020, 131:108976.
[4] LI Y F, ZHANG Z F, YANG L L, et al.Colla corii asini might upregulate ZNF471 and THOC5 by KRAB domain-containing zinc-finger protein pathway and THO complex subunit 5 pathway to improve anemia of pregnant women with β-thalassemia[J].Annals of hematology, 2019, 98(8):1 813-1 826.
[5] WU H Z, REN C Y, YANG F, et al.Extraction and identification of collagen-derived peptides with hematopoietic activity from Colla Corii Asini[J].Journal of Ethnopharmacology, 2016, 182:129-136.
[6] 吴宏忠. 阿胶补血作用的物质基础及分子机理研究[D].上海:华东理工大学, 2008.
WU H Z.Study on the material basis and molecular mechanism of donkey-hide gelatiŃs effect on blood[D].Shanghai:East China University of Science and Technology, 2008.
[7] WU W M, HE L C, LIANG Y H, et al.Preparation process optimization of pig bone collagen peptide-calcium chelate using response surface methodology and its structural characterization and stability analysis[J].Food Chemistry, 2019, 284:80-89.
[8] HORIMOTO Y, TAN R, LIM L T.Enzymatic treatment of pork protein for the enhancement of iron bioavailability[J].International Journal of Food Sciences and Nutrition, 2019, 70(1):41-52.
[9] WALTERS M E, ESFANDI R, TSOPMO A.Potential of food hydrolyzed proteins and peptides to chelate iron or calcium and enhance their absorption[J].Foods, 2018, 7(10):172.
[10] CAETANO-SILVA M E, NETTO F M, BERTOLDO-PACHECO M T, et al.Peptide-metal complexes:Obtention and role in increasing bioavailability and decreasing the pro-oxidant effect of minerals[J].Critical Reviews in Food Science and Nutrition, 2021,61(9):1 470-1 489.
[11] MINEKUS M, ALMINGER M, ALVITO P, et al.A standardised static in vitro digestion method suitable for food — An international consensus[J].Food & Function, 2014, 5(6):1 113-1 124.
[12] MIYAKE M, KOGA T, KONDO S, et al.Prediction of drug intestinal absorption in human using the Ussing chamber system:A comparison of intestinal tissues from animals and humans[J].European Journal of Pharmaceutical Sciences, 2017, 96(1):373-380.
[13] SJÖGREN E, ERIKSSON J, VEDIN C, et al.Excised segments of rat small intestine in Ussing chamber studies:A comparison of native and stripped tissue viability and permeability to drugs[J].International Journal of Pharmaceutics, 2016, 505(1-2):361-368.
[14] GUO L D, HARNEDY P A, O KEEFFE M B, et al.Fractionation and identification of Alaska pollock skin collagen-derived mineral chelating peptides[J].Food Chemistry, 2015, 173:536-542.
[15] 唐顺博. 鱼鳞胶原肽亚铁螯合物的制备及性质研究[D].南昌:江西师范大学, 2020.
TANG S B.Preparation and properties of ferrous chelate of fish scale collagen peptide[D].Nanchang:Jiangxi Normal University, 2020.
[16] LYU Y, WEI K H, MENG X G, et al.Separation and identification of iron-chelating peptides from defatted walnut flake by nano LC-ESI-MS/MS and de novo sequencing[J].Process Biochemistry, 2017, 59:223-228.
[17] WU W F, LI B F, HOU H, et al.Identification of iron-chelating peptides from Pacific cod skin gelatin and the possible binding mode[J].Journal of Functional Foods, 2017, 35:418-427.
[18] CHEN M, JI H W, ZHANG Z W, et al.A novel calcium-chelating peptide purified from Auxis thazard protien hydrolysate and its binding properties with calcium[J].Journal of Functional Foods, 2019, 60:103447.
[19] SUN R N, LIU X F, YU Y, et al.Preparation process optimization, structural characterization and in vitro digestion stability analysis of Antarctic krill (Euphausia superba) peptides-zinc chelate[J].Food Chemistry, 2021, 340:128056.
[20] MIYAKE M, KONDO S, KOGA T, et al.Evaluation of intestinal metabolism and absorption using the Ussing chamber system equipped with intestinal tissue from rats and dogs[J].European Journal of Pharmaceutics and Biopharmaceutics, 2018, 122:49-53.
[21] LI Y N, JIANG H, HUANG G R.Protein hydrolysates as promoters of non-haem iron absorption[J].Nutrients, 2017, 9(6):609-627.
[22] LYU Y, LIU Q, BAO X L, et al.Identification and characteristics of iron-chelating peptides from soybean protein hydrolysates using IMAC-Fe3+[J].Journal of Agricultural and Food Chemistry, 2009, 57(11):4 593-4 597.
[23] SUN N, CUI P B, JIN Z Q, et al.Contributions of molecular size, charge distribution, and specific amino acids to the iron-binding capacity of sea cucumber (Stichopus japonicus) ovum hydrolysates[J].Food Chemistry, 2017, 230:627-636.
[24] SARABANDI K, JAFARI S M.Fractionation of flaxseed-Derived bioactive peptides and their influence on nanoliposomal carriers[J].Journal of Agricultural and Food Chemistry, 2020, 68(51):15 097-15 106.
[25] LEE S H, SONG K B.Purification of an iron-binding nona-peptide from hydrolysates of porcine blood plasma protein[J].Process biochemistry, 2009, 44(3):378-381.
[26] 王宁. 分子光谱和等温滴定量热法研究蛋白与小分子的相互作用[D].郑州:郑州大学, 2019.
WANG N.Study of Interaction between protein and small molecules by molecular spectroscopy and isothermal titration calorimetry[D].Zhengzhou:Zhengzhou University, 2019.
[27] ZHOU J, WANG X, AI T, et al.Preparation and characterization of β-lactoglobulin hydrolysate-iron complexes[J].Journal of Dairy Science, 2012, 95(8):4 230-4 236.
[28] BEYER R L, HOANG H N, APPLETON T G, et al.Metal clips induce folding of a short unstructured peptide into an α-helix via turn conformations in water.Kinetic versus thermodynamic products[J].Journal of the American Chemical Society, 2004, 126(46):15 096-15 105.
