Reversed-phase high-performance liquid chromatography （RP-HPLC） method with C4 column and C18 column for analyzing β-lactoglobulin and α-lactalbumin in bovine milk was developed and the performance and characteris...Reversed-phase high-performance liquid chromatography （RP-HPLC） method with C4 column and C18 column for analyzing β-lactoglobulin and α-lactalbumin in bovine milk was developed and the performance and characteristic of two columns were compared. Shiseido Proteonavi C4 column （250 mm×4.6 mm×5μm） and Shiseido CAPCELL PAK SG 300 C18 column （250 mm× 4.6 mm×5 μm） were used in the experiment. Phase A was composed of 0.1% （V/V） trifluoroacetic acid （TFA） in ultrapure water and Phase B （organic phase） was composed of 0.1% TFA in acetonitrile. Gradient elution was taken. Flow rate was 1 mL min-1. The detection wavelength was 215 nm. The injection volume was 20 μL and the column temperature was 30℃. The results showed that linear relationship was good and recovery of α-lactalbumin and β-lactoglobulin was 86.12%-104.38%, C18 column had stronger ability to resist acid and more stable, and the method with C4 column had excellent sensitivities and good separation.展开更多
Five female transgenic mice were produced by microinjection using a construct made up of a 7.3-kb-5′ flanking region and a 2.0-kb coding region of human a-lactalbumin, as well as a 227-bp 3′-flanking region from bov...Five female transgenic mice were produced by microinjection using a construct made up of a 7.3-kb-5′ flanking region and a 2.0-kb coding region of human a-lactalbumin, as well as a 227-bp 3′-flanking region from bovine growth hormone gene. A founder female ex-pressed human a-lactalbumin as much as 0.3 g per liter of its milk, approximately a 3-fold in-crease in the total a-lactalbumin concentration of the transgenic mouse milk. Compared with the normal mice, the expression profile of the ha-Lac transgene in the transgenics is different during the lactation, showing low level in the first 3 days and becoming increased from day 4, then gradually reaching and stabilizing at the highest level from day 13. In addition, the milk yielding volume in the transgenics tended to be higher than in normal mice, suggesting higher concen-trations of a-lactalbumin might boost more milk output.展开更多
Chitosan(Ct)andα-lactalbumin(ALa)were applied as the carriers,their biopolymer nanoparticle was designed to encapsulate retinol(VA).Zeta potential and turbidity measurements,demonstrated that the most suitable pH val...Chitosan(Ct)andα-lactalbumin(ALa)were applied as the carriers,their biopolymer nanoparticle was designed to encapsulate retinol(VA).Zeta potential and turbidity measurements,demonstrated that the most suitable pH value in the formation of Ct/ALa nanoparticle was 6.0,and its optimal Ct/ALa mass ratio was 1:4.At this ratio,scanning electron microscopy(SEM)of Ct/ALa nanoparticle showed that Ct was coated on the surface of ALa/VA as a shell.Meanwhile,the encapsulation efficiency(EE)and loading capacity(LC)of above nano-sized Ct/ALa particle for VA were 82.22±1.78%and 3.13±0.12%,respectively.Moreover,Ct/ALa nanoparticle not only improved the storage stability of VA,but also protected VA from the destruction of simulated gastrointestinal juice to a certain extent during in vitro digestion.Information from this study could supply the novel opinion for the protection and delivery of photosensitive bioactive substances(VA)in functional dairy-based product.展开更多
Bovineα-lactalbumin(BLA)induced severe cow's milk allergy.In this study,a novel strategy combining ultrasonication,performed before glycation,and phosphorylation was proposed to reduce BLA allergenicity.Result sh...Bovineα-lactalbumin(BLA)induced severe cow's milk allergy.In this study,a novel strategy combining ultrasonication,performed before glycation,and phosphorylation was proposed to reduce BLA allergenicity.Result showed that IgE-and IgG-binding capacities and the release rates of histamine and interleukin-6 from RBL-2 H3 were reduced.Moreover,intrinsic fluorescence intensity and surface hydrophobicity were decreased,whereas glycated sites(R10,N44,K79,K108,N102 and K114)and phosphorylated sites(Y36 and S112)of BLA were increased.Minimum allergenicity was detected during BLA treatment after ultrasonic prior to glycation and subsequent phosphorylation because of considerable increase in glycated and phosphorylated sites.Therefore,the decrease in allergenicity of BLA,the effect correlated well with the shielding effect of glycated sites combined with phosphorylated sites and the conformational changes.This study provides important theoretical foundations for improving and using the ultrasonic technology combined with protein modification in allergenic protein processing.展开更多
α-lactalbumin (α-LA) might increase its antioxidant potential after hydrolysis. In particular, low molecular weight (LMW) peptides showed greater antioxidant capacity. Different hydrolysis conditions with Alcalase e...α-lactalbumin (α-LA) might increase its antioxidant potential after hydrolysis. In particular, low molecular weight (LMW) peptides showed greater antioxidant capacity. Different hydrolysis conditions with Alcalase enzyme were optimized with a composite central design and surface methodology. Sample obtained after 0.1% (w/w enzyme:substrate), 60 min hydrolysis, ultrafiltrated with membranes of 3 kDa (named 4 LMW), showed the greatest antioxidant values: 1.574 ± 0.060 and 1.636 ± 0.076 μmolTE/mg of protein for ABTS and ORAC-FL, respectively. Sample 4 LMW produced mild ACE inhibition capacity, 22% related to Captopril. 4 LMW was submitted to in vitro gastrointestinal conditions using α-amylase, pepsin, pancreatin and bile-extract;its antioxidant capacity was enhanced by the shorter peptides released, confirmed by SE-HPLC. Antioxidant capacity of digested 4 LMW sample (D 4 LMW) was 1.743 ± 0.086 and 2.542 ± 0.245 μmolTE/mg of protein for ABTS and ORAC-FL, respectively, showing improvement on bioaccessibility. Intestinal cells viability was higher for D 4 LMW.展开更多
为了探讨α-乳白蛋白(α-lactalbumin,α-LA)降低丙烯酰胺血液学毒性作用机理,通过分子对接法探究α-LA与丙烯酰胺(Acrylamide,ACR)能否相互作用及其对接结合位点,并运用分子动力学仿真方法分析α-LA-ACR结合物稳定性。分子的准备和对...为了探讨α-乳白蛋白(α-lactalbumin,α-LA)降低丙烯酰胺血液学毒性作用机理,通过分子对接法探究α-LA与丙烯酰胺(Acrylamide,ACR)能否相互作用及其对接结合位点,并运用分子动力学仿真方法分析α-LA-ACR结合物稳定性。分子的准备和对接采用UCSF Chimera和其中的Auto Dock Vina,分子动力学仿真以ubuntu虚拟机中Gromacs为基础进行模拟计算。α-LA和ACR分子对接结果表明二者间有相互作用的可能。在分子动力学模拟中,分别对α-LA均方根误差(RMSD)、回转半径(Rg)和均方根浮动(RMSF)进行分析。将ICR小鼠随机分为4组,分别为对照组、ACR组、α-LA组、(α-LA+ACR)组,每天1次连续灌胃21 d,结束后,心脏取血,对全血进行分析,并测定红细胞的渗透脆性。结果表明,α-LA与ACR的相互作用对α-LA结构产生了较大影响。ACR能显著改变小鼠多项血液指标,并且能显著增大红细胞渗透脆性,而α-LA对ACR血液学毒性有抑制作用。文章为探究α-LA与ACR相互作用时如何降低ACR对人体负面影响提供了理论依据。展开更多
基金Supported by the Project of Science & Technology Plans in Heilongjiang Province in the 11th Five-year Period (GB07B407)
文摘Reversed-phase high-performance liquid chromatography （RP-HPLC） method with C4 column and C18 column for analyzing β-lactoglobulin and α-lactalbumin in bovine milk was developed and the performance and characteristic of two columns were compared. Shiseido Proteonavi C4 column （250 mm×4.6 mm×5μm） and Shiseido CAPCELL PAK SG 300 C18 column （250 mm× 4.6 mm×5 μm） were used in the experiment. Phase A was composed of 0.1% （V/V） trifluoroacetic acid （TFA） in ultrapure water and Phase B （organic phase） was composed of 0.1% TFA in acetonitrile. Gradient elution was taken. Flow rate was 1 mL min-1. The detection wavelength was 215 nm. The injection volume was 20 μL and the column temperature was 30℃. The results showed that linear relationship was good and recovery of α-lactalbumin and β-lactoglobulin was 86.12%-104.38%, C18 column had stronger ability to resist acid and more stable, and the method with C4 column had excellent sensitivities and good separation.
文摘Five female transgenic mice were produced by microinjection using a construct made up of a 7.3-kb-5′ flanking region and a 2.0-kb coding region of human a-lactalbumin, as well as a 227-bp 3′-flanking region from bovine growth hormone gene. A founder female ex-pressed human a-lactalbumin as much as 0.3 g per liter of its milk, approximately a 3-fold in-crease in the total a-lactalbumin concentration of the transgenic mouse milk. Compared with the normal mice, the expression profile of the ha-Lac transgene in the transgenics is different during the lactation, showing low level in the first 3 days and becoming increased from day 4, then gradually reaching and stabilizing at the highest level from day 13. In addition, the milk yielding volume in the transgenics tended to be higher than in normal mice, suggesting higher concen-trations of a-lactalbumin might boost more milk output.
基金supported by project for the Natural Science Foundation of China(No.32172164)Natural Key Science Foundation of Heilongjiang Province of China(No.ZD2021C007)Key Program of Heilongjiang Province of China(No.2019ZX07B02-04).
文摘Chitosan(Ct)andα-lactalbumin(ALa)were applied as the carriers,their biopolymer nanoparticle was designed to encapsulate retinol(VA).Zeta potential and turbidity measurements,demonstrated that the most suitable pH value in the formation of Ct/ALa nanoparticle was 6.0,and its optimal Ct/ALa mass ratio was 1:4.At this ratio,scanning electron microscopy(SEM)of Ct/ALa nanoparticle showed that Ct was coated on the surface of ALa/VA as a shell.Meanwhile,the encapsulation efficiency(EE)and loading capacity(LC)of above nano-sized Ct/ALa particle for VA were 82.22±1.78%and 3.13±0.12%,respectively.Moreover,Ct/ALa nanoparticle not only improved the storage stability of VA,but also protected VA from the destruction of simulated gastrointestinal juice to a certain extent during in vitro digestion.Information from this study could supply the novel opinion for the protection and delivery of photosensitive bioactive substances(VA)in functional dairy-based product.
基金supported by Science Foundation for Young Scientists of Jiangxi Province(20202BABL215027)National Natural Science Foundation of China(31960457)。
文摘Bovineα-lactalbumin(BLA)induced severe cow's milk allergy.In this study,a novel strategy combining ultrasonication,performed before glycation,and phosphorylation was proposed to reduce BLA allergenicity.Result showed that IgE-and IgG-binding capacities and the release rates of histamine and interleukin-6 from RBL-2 H3 were reduced.Moreover,intrinsic fluorescence intensity and surface hydrophobicity were decreased,whereas glycated sites(R10,N44,K79,K108,N102 and K114)and phosphorylated sites(Y36 and S112)of BLA were increased.Minimum allergenicity was detected during BLA treatment after ultrasonic prior to glycation and subsequent phosphorylation because of considerable increase in glycated and phosphorylated sites.Therefore,the decrease in allergenicity of BLA,the effect correlated well with the shielding effect of glycated sites combined with phosphorylated sites and the conformational changes.This study provides important theoretical foundations for improving and using the ultrasonic technology combined with protein modification in allergenic protein processing.
文摘α-lactalbumin (α-LA) might increase its antioxidant potential after hydrolysis. In particular, low molecular weight (LMW) peptides showed greater antioxidant capacity. Different hydrolysis conditions with Alcalase enzyme were optimized with a composite central design and surface methodology. Sample obtained after 0.1% (w/w enzyme:substrate), 60 min hydrolysis, ultrafiltrated with membranes of 3 kDa (named 4 LMW), showed the greatest antioxidant values: 1.574 ± 0.060 and 1.636 ± 0.076 μmolTE/mg of protein for ABTS and ORAC-FL, respectively. Sample 4 LMW produced mild ACE inhibition capacity, 22% related to Captopril. 4 LMW was submitted to in vitro gastrointestinal conditions using α-amylase, pepsin, pancreatin and bile-extract;its antioxidant capacity was enhanced by the shorter peptides released, confirmed by SE-HPLC. Antioxidant capacity of digested 4 LMW sample (D 4 LMW) was 1.743 ± 0.086 and 2.542 ± 0.245 μmolTE/mg of protein for ABTS and ORAC-FL, respectively, showing improvement on bioaccessibility. Intestinal cells viability was higher for D 4 LMW.
文摘为了探讨α-乳白蛋白(α-lactalbumin,α-LA)降低丙烯酰胺血液学毒性作用机理,通过分子对接法探究α-LA与丙烯酰胺(Acrylamide,ACR)能否相互作用及其对接结合位点,并运用分子动力学仿真方法分析α-LA-ACR结合物稳定性。分子的准备和对接采用UCSF Chimera和其中的Auto Dock Vina,分子动力学仿真以ubuntu虚拟机中Gromacs为基础进行模拟计算。α-LA和ACR分子对接结果表明二者间有相互作用的可能。在分子动力学模拟中,分别对α-LA均方根误差(RMSD)、回转半径(Rg)和均方根浮动(RMSF)进行分析。将ICR小鼠随机分为4组,分别为对照组、ACR组、α-LA组、(α-LA+ACR)组,每天1次连续灌胃21 d,结束后,心脏取血,对全血进行分析,并测定红细胞的渗透脆性。结果表明,α-LA与ACR的相互作用对α-LA结构产生了较大影响。ACR能显著改变小鼠多项血液指标,并且能显著增大红细胞渗透脆性,而α-LA对ACR血液学毒性有抑制作用。文章为探究α-LA与ACR相互作用时如何降低ACR对人体负面影响提供了理论依据。
