The interaction of gallium（Ⅲ） with the ligands containing phenolic group（s）, such as salicylic acid, 8-hydroxyquinoline, N,N＇-bis（2-hydroxybenzyl）ethylenediamine-N,N＇diacetic acid （HBED）, N,N＇-ethylenebis...The interaction of gallium（Ⅲ） with the ligands containing phenolic group（s）, such as salicylic acid, 8-hydroxyquinoline, N,N＇-bis（2-hydroxybenzyl）ethylenediamine-N,N＇diacetic acid （HBED）, N,N＇-ethylenebis[2-（o- hydroxyphenyl）glycine （EHPG）, and ovotransferrin, was studied, respectively, by means of fluorescence in 0.01 mol/L Hepes at pH 7.4 and room temperature. Fluorescence intensity showed an increase when gallium（Ⅲ） was bound to 8-hydroxyquinoline and HBED. In contrast, it was decreased with the interaction of gallium（Ⅲ） with salicylic acid and EHPG. At pH 7.4, there was N…H-O type intramolecular hydrogen bond in the former, and the latter existed O…H-O type intramolecular hydrogen bond. Fluorescence titration of apoovotransferrin with gallium（Ⅲ） displayed that the fluorescence intensity was decreased at the N-terminal binding site, while enhanced at the C-terminal binding site. It can account for the O…H-O type intramolecular hydrogen bonds for the phenolic groups of Tyr92 and Tyr191 residues at the N-terminal binding site. And there are N…H-O type intramolecular hydrogen bonds for Tyr431 and Tyr524 residues at the C-terminal binding site. In addition, under the same conditions, the conditional binding constant of gallium（Ⅲ） with EHPG or HBED determined by fluorescence method is lg KGa-EHPG=19.18 or lg KGa-HBED= 19.08.展开更多
鸡蛋是引起食物过敏最常见的食物之一。为了快速高效分离鸡蛋中主要过敏原卵转铁蛋白,开展鸡蛋过敏的研究,采用DEAE-Sepharose Fast Flow阴离子交换层析一步分离出高纯度、高回收率的卵转铁蛋白,纯度达97%,回收率为87.47%。本实验所建...鸡蛋是引起食物过敏最常见的食物之一。为了快速高效分离鸡蛋中主要过敏原卵转铁蛋白,开展鸡蛋过敏的研究,采用DEAE-Sepharose Fast Flow阴离子交换层析一步分离出高纯度、高回收率的卵转铁蛋白,纯度达97%,回收率为87.47%。本实验所建立的方法操作简便,设备简单,分离效率高,纯化出的卵转铁蛋白可为进一步研究提供实验材料。展开更多
Ovotransferrin,an iron-binding glycoprotein,accounting for approximately 12%of egg white protein,is a member of transferrin fam ily.Our previous studies showed that ovotransferrin stimulates the proliferation and diff...Ovotransferrin,an iron-binding glycoprotein,accounting for approximately 12%of egg white protein,is a member of transferrin fam ily.Our previous studies showed that ovotransferrin stimulates the proliferation and differentiation of osteoblasts,while inhibits osteoclastogenesis and resorption activity.The work aims to study the efficacy of orally administered ovotransferrin on the prevention of osteoporosis using ovariectomized(OVX)Sprague-Dawley rats.Oral administration of ovotransferrin showed no negative effect on body weight,food intake and organ weight.After 12-week treatment,feeding ovotransferrin at a dose of 1%(1 g ovotransferrin/100 g diet)prevented OVX-induced bone loss and maintained relatively high bone mineral density and integrated bone microarchitecture.The serum concentration of biomarkers indicating bone formation was increased in ovotransferrin administration groups,while the bone resorption biomarkers were decreased.Ovotransferrin feeding also decreased the production of serum cytokine TNF-αand IL-6,which are two stimulators for osteoclast differentiation.In addition to its direct regulatory role on bone turnover,ovotransferrin supplementation might benefit osteoporosis prevention by inhibiting adipogenesis,and regulating immune response.Our results suggested the potential application of ovotransferrin as a functional food ingredient on the prevention of osteoporosis.展开更多
Antibacterial peptides mixture purified from Ovotransferrin by pepsin digest was used as the raw material. Peptide sections with good antibacterial activity were determined after bacteriostasis experiments, its molecu...Antibacterial peptides mixture purified from Ovotransferrin by pepsin digest was used as the raw material. Peptide sections with good antibacterial activity were determined after bacteriostasis experiments, its molecular weight and amino acid composition were analyzed. The results of experiments indicate that with Sephadex G-50 and distilled water as mobile phase, detection wavelength 220 nm, flow rate 1.5 mL/min, sample density 0.2 g/mL, and volume 0.2 mL are the optimal conditions. Bacteriostasis experiments of the fraction of purified peaks were carried out and the result was： peak 1peak 3peak 2; the molecular weight of peak 1 was about 3015 by high performance liquid chromatography; active peptide possessed positive charges by amino acid analysis, its cationic characteristics are in accordance with the nature of antimicrobial peptides.展开更多
The rates at which aluminum was removed from the N- and C-terminal monoaluminum ovotransferrins by py-rophosphate were evaluated by UV difference spectra in 0.01 mol/L Hepes, pH=7.4 and at 37 ℃. Pesudo first-order ra...The rates at which aluminum was removed from the N- and C-terminal monoaluminum ovotransferrins by py-rophosphate were evaluated by UV difference spectra in 0.01 mol/L Hepes, pH=7.4 and at 37 ℃. Pesudo first-order rate constants as a function of pyrophosphate concentration were measured. The results indicate that the pathways of aluminum removal are different. For the N-terminal binding site, aluminum removal follows simple saturation kinetics, while the removal of aluminum from the C-terminal binding site reverts to the combination of saturation and first-order kinetics. The saturation component is consistent with a rate-limiting conformational change in the protein as has been reported. We propose that the first-order kinetics mechanism is attributed to a pre-equilibrium process. The rate constants of saturation kinetics are accelerated from both terminals with the addi-tion of 0.1 mol/L chloride to the monoaluminum ovotransferrin solutions, whereas the rates of the first-order kinet-ics are decreased for the C-terminal binding site. The effect of chloride ionic strength causes a continuing increase on kobs for the N- and C-terminal binding sites. Moreover, the kinetics behavior of the N-terminal is more easily af-fected by chloride than that of the C-terminal. In the experiment presumably the N-terminal site is apparently ki-netically more labile than the C-terminal site.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 20371031 ） and the Shanxi Provincial Natural Science Foundation for Youth （No. 20051006）.
文摘The interaction of gallium（Ⅲ） with the ligands containing phenolic group（s）, such as salicylic acid, 8-hydroxyquinoline, N,N＇-bis（2-hydroxybenzyl）ethylenediamine-N,N＇diacetic acid （HBED）, N,N＇-ethylenebis[2-（o- hydroxyphenyl）glycine （EHPG）, and ovotransferrin, was studied, respectively, by means of fluorescence in 0.01 mol/L Hepes at pH 7.4 and room temperature. Fluorescence intensity showed an increase when gallium（Ⅲ） was bound to 8-hydroxyquinoline and HBED. In contrast, it was decreased with the interaction of gallium（Ⅲ） with salicylic acid and EHPG. At pH 7.4, there was N…H-O type intramolecular hydrogen bond in the former, and the latter existed O…H-O type intramolecular hydrogen bond. Fluorescence titration of apoovotransferrin with gallium（Ⅲ） displayed that the fluorescence intensity was decreased at the N-terminal binding site, while enhanced at the C-terminal binding site. It can account for the O…H-O type intramolecular hydrogen bonds for the phenolic groups of Tyr92 and Tyr191 residues at the N-terminal binding site. And there are N…H-O type intramolecular hydrogen bonds for Tyr431 and Tyr524 residues at the C-terminal binding site. In addition, under the same conditions, the conditional binding constant of gallium（Ⅲ） with EHPG or HBED determined by fluorescence method is lg KGa-EHPG=19.18 or lg KGa-HBED= 19.08.
文摘鸡蛋是引起食物过敏最常见的食物之一。为了快速高效分离鸡蛋中主要过敏原卵转铁蛋白,开展鸡蛋过敏的研究,采用DEAE-Sepharose Fast Flow阴离子交换层析一步分离出高纯度、高回收率的卵转铁蛋白,纯度达97%,回收率为87.47%。本实验所建立的方法操作简便,设备简单,分离效率高,纯化出的卵转铁蛋白可为进一步研究提供实验材料。
基金funded by grants from Egg Farmers of Canada,Global Egg Corp.,and Natural Sciences and Engineering Research Council of Canada(NSERC)。
文摘Ovotransferrin,an iron-binding glycoprotein,accounting for approximately 12%of egg white protein,is a member of transferrin fam ily.Our previous studies showed that ovotransferrin stimulates the proliferation and differentiation of osteoblasts,while inhibits osteoclastogenesis and resorption activity.The work aims to study the efficacy of orally administered ovotransferrin on the prevention of osteoporosis using ovariectomized(OVX)Sprague-Dawley rats.Oral administration of ovotransferrin showed no negative effect on body weight,food intake and organ weight.After 12-week treatment,feeding ovotransferrin at a dose of 1%(1 g ovotransferrin/100 g diet)prevented OVX-induced bone loss and maintained relatively high bone mineral density and integrated bone microarchitecture.The serum concentration of biomarkers indicating bone formation was increased in ovotransferrin administration groups,while the bone resorption biomarkers were decreased.Ovotransferrin feeding also decreased the production of serum cytokine TNF-αand IL-6,which are two stimulators for osteoclast differentiation.In addition to its direct regulatory role on bone turnover,ovotransferrin supplementation might benefit osteoporosis prevention by inhibiting adipogenesis,and regulating immune response.Our results suggested the potential application of ovotransferrin as a functional food ingredient on the prevention of osteoporosis.
基金Supported by the Applied Basic Fund of Jilin Provincial Science and Technology Department(No.20070572)the Frontiers of Science of Jilin University and Innovation Fund of Interdisciplinary, China(No.200903224)
文摘Antibacterial peptides mixture purified from Ovotransferrin by pepsin digest was used as the raw material. Peptide sections with good antibacterial activity were determined after bacteriostasis experiments, its molecular weight and amino acid composition were analyzed. The results of experiments indicate that with Sephadex G-50 and distilled water as mobile phase, detection wavelength 220 nm, flow rate 1.5 mL/min, sample density 0.2 g/mL, and volume 0.2 mL are the optimal conditions. Bacteriostasis experiments of the fraction of purified peaks were carried out and the result was： peak 1peak 3peak 2; the molecular weight of peak 1 was about 3015 by high performance liquid chromatography; active peptide possessed positive charges by amino acid analysis, its cationic characteristics are in accordance with the nature of antimicrobial peptides.
基金Project supported by the National Natural Science Foundation of China (Nos. 20371031 20071022).
文摘The rates at which aluminum was removed from the N- and C-terminal monoaluminum ovotransferrins by py-rophosphate were evaluated by UV difference spectra in 0.01 mol/L Hepes, pH=7.4 and at 37 ℃. Pesudo first-order rate constants as a function of pyrophosphate concentration were measured. The results indicate that the pathways of aluminum removal are different. For the N-terminal binding site, aluminum removal follows simple saturation kinetics, while the removal of aluminum from the C-terminal binding site reverts to the combination of saturation and first-order kinetics. The saturation component is consistent with a rate-limiting conformational change in the protein as has been reported. We propose that the first-order kinetics mechanism is attributed to a pre-equilibrium process. The rate constants of saturation kinetics are accelerated from both terminals with the addi-tion of 0.1 mol/L chloride to the monoaluminum ovotransferrin solutions, whereas the rates of the first-order kinet-ics are decreased for the C-terminal binding site. The effect of chloride ionic strength causes a continuing increase on kobs for the N- and C-terminal binding sites. Moreover, the kinetics behavior of the N-terminal is more easily af-fected by chloride than that of the C-terminal. In the experiment presumably the N-terminal site is apparently ki-netically more labile than the C-terminal site.
