INTRODUCTIONSialyl Lewis-X antigen ,correlated with carcinoma, is a group of carbohydrate antigen containing oligosaccharide expressed of embryonic tisue and glycoproteins on cell surface of embryonic tissue[1].The SL...INTRODUCTIONSialyl Lewis-X antigen ,correlated with carcinoma, is a group of carbohydrate antigen containing oligosaccharide expressed of embryonic tisue and glycoproteins on cell surface of embryonic tissue[1].The SLeX antigen located on cell surface is synthesized principally by two enzymes ,al ,3fucosyltransfrease and a2, 3sialyctransferase.In adults ,SLeX antigen is expressed principally on the surfaces of granulocytic cells and some tumor cells .展开更多
Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active in...Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.展开更多
N-Acetylneuraminic acid(Neu5Ac),the most common type of Sia,generally acts as the terminal sugar in cell surface glycans,glycoconjugates,oligosaccharides,lipo-oligosaccharides,and polysaccharides,thus exerting numerou...N-Acetylneuraminic acid(Neu5Ac),the most common type of Sia,generally acts as the terminal sugar in cell surface glycans,glycoconjugates,oligosaccharides,lipo-oligosaccharides,and polysaccharides,thus exerting numerous physiological functions.The extensive applications of Neu5Ac in the food,cosmetic,and pharmaceutical industries make large-scale production of this chemical desirable.Biosynthesis which is associated with important application potential and environmental friendliness has become an indispensable approach for large-scale synthesis of Neu5Ac.In this review,the physiological roles of Neu5Ac was first summarized in detail.Second,the safety evaluation,regulatory status,and applications of Neu5Ac were discussed.Third,enzyme-catalyzed preparation,whole-cell biocatalysis,and microbial de novo synthesis of Neu5Ac were comprehensively reviewed.In addition,we discussed the main challenges of Neu5Ac de novo biosynthesis,such as screening and engineering of key enzymes,identifying exporters of intermediates and Neu5Ac,and balancing cell growth and biosynthesis.The corresponding strategies and systematic strategies were proposed to overcome these challenges and facilitate Neu5Ac industrial-scale production.展开更多
N-acetylneuraminic acid(NeuAc)is an important nutrient that plays a key role in brain development in infants NeuAc is mainly produced by extraction from natural resources such as edible birds’s nests,crucian eggs,cav...N-acetylneuraminic acid(NeuAc)is an important nutrient that plays a key role in brain development in infants NeuAc is mainly produced by extraction from natural resources such as edible birds’s nests,crucian eggs,caviar and human breast milk.The extraction process is complicated,resulting in the disadvantages of low NeuAc content and low recovery rate.In this study,a crude enzyme immobilization-based cell-free system(CEICFS)was developed for efficient NeuAc biosynthesis.First,N-terminal coding sequences that improved the expression levels of N-acetylglucosamine-2-epimerase(AGE)and N-acetylneuraminic acid aldolase(NanA)were obtained by high-throughput screening.And these sequences resulted in up to 1.5-fold(1.2-fold)increase in AGE(NanA)enzyme levels.And then,a CEICFS for NeuAc biosynthesis was proposed by directly immobilizing crude enzyme containing AGE and NanA on amino resin.Subsequently,NeuAc production from GlcNAc using CEICFS in one reactor was carried out,resulting 68 g/L of NeuAc and the highest productivity of 6.8 g/L/h.Further,the enzyme activity was still higher than 75%after five repeated uses.The functional properties of CEICFS were studied and compared to those of the free enzyme,immobilization can extend the application of enzyme to some harsh environments,such as low temperature and acidic environment.Therefore,CEICFS with excellent heat resistance,storage stability and reusability exhibit great potential for industrial application.展开更多
AIM:This study was designed to evaluate the clinical application of serum total sialic acid (TSA) in the diagnosis of cholangiocarcinoma (CCA).METHODS: Serum TSA was determined by periodateresorcinol microassay in 69 ...AIM:This study was designed to evaluate the clinical application of serum total sialic acid (TSA) in the diagnosis of cholangiocarcinoma (CCA).METHODS: Serum TSA was determined by periodateresorcinol microassay in 69 patients with CCA, 59 patients with hepatocellular carcinoma (HCC), 37 patients with cirrhosis, 61 patients with chronic hepatitis and 50 healthy blood donors.RESULTS: The mean serum TSA concentration in CCA (2.41±0.70 mmol/L) was significantly higher than those of HCC, cirrhosis, chronic hepatitis and healthy blood donors (1.41±0.37 mmol/L, 1.13±0.31 mmol/L, 1.16±0.26 mmol/L, and 1.10±0.14 mmol/L, respectively; P＜0.001). Based on ROC curve analysis, a cut-off point of 1.75 mmol/L discriminated between CCA and HCC with a sensitivity,specificity and accuracy of 82.6%, 83.1%, and 82.8%,respectively.CONCLUSION: Based on our results, serum TSA would be a useful marker for the differential diagnosis of CCA from HCC.展开更多
AIM To investigate the bactericidal effects of calcium chelated N-acetylneuraminic acid-glycomacropeptide(CaG-NANA) against Helicobacter pylori(H.pylori).METHODS For manufacture of Ca G-NANA,calcium(Ca) was combined w...AIM To investigate the bactericidal effects of calcium chelated N-acetylneuraminic acid-glycomacropeptide(CaG-NANA) against Helicobacter pylori(H.pylori).METHODS For manufacture of Ca G-NANA,calcium(Ca) was combined with glycomacropeptide(GMP) by chelating,and N-acetylneuraminic acid(NANA) was produced with Ca-GMP substrate by an enzymatic method.The final concentration of each component was 5% Ca,7% NANA,85% GMP,and 3% water.For in vitro study,various concentrations of CaG-NANA were investigated under the minimal inhibitory concentration(MIC).For in vivo study,Ca G-NANA was administered orally for 3 wk after H.pylori infection.The levels of inflamma-tory cytokines in blood were analyzed by enzyme-linked immunosorbent assay and eradication of H.pylori was assessed by histological observation.RESULTS The time-kill curves showed a persistent decrease in cellnumbers,which depended on the dose of CaG-NANA,and MIC of Ca G-NANA against H.pylori was 0.5% in vitro.Histopathologic observation revealed no obvious inflammation or pathologic changes in the gastric mucosa in the CaG-NANA treatment group in vivo.The colonization of H.pylori was reduced after CaG-NANA treatment.The levels of interleukin(IL)-6,IL-1β,tumor necrosis factor-α,and IL-10 were also decreased by CaG-NANA.CONCLUSION Ca G-NANA demonstrates effective anti-bactericidal activity against H.pylori both in vitro and in vivo.展开更多
Due to their important biological role as markers for different pathologies, sialic acid （SA） analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie de...Due to their important biological role as markers for different pathologies, sialic acid （SA） analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie detection （mini-CE-AD） was developed for the determination of N-aeetylneuraminic acid （NANA）, which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β-formyl pyruvic acid was derivatized with electroactive 2-thiobarbituric acid （TBA） to form an electroactive NANA-TBA adduct, which could be readily determined by mini-CE-AD. The limit of detection （LOD） of NANA-TBA could achieve 0.50 μg/mL （1.6 μmol·L-1, S/N=3） based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8%-109% with RSDs of 1.8%-3.9%. Due to its simple design and construction, low cost and portability, the mini-CE-AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.展开更多
文摘INTRODUCTIONSialyl Lewis-X antigen ,correlated with carcinoma, is a group of carbohydrate antigen containing oligosaccharide expressed of embryonic tisue and glycoproteins on cell surface of embryonic tissue[1].The SLeX antigen located on cell surface is synthesized principally by two enzymes ,al ,3fucosyltransfrease and a2, 3sialyctransferase.In adults ,SLeX antigen is expressed principally on the surfaces of granulocytic cells and some tumor cells .
文摘Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.
基金the National Key R&D Program of China(No.2022YFC2104900)the National Natural Science Foundation of China(No.31922073).
文摘N-Acetylneuraminic acid(Neu5Ac),the most common type of Sia,generally acts as the terminal sugar in cell surface glycans,glycoconjugates,oligosaccharides,lipo-oligosaccharides,and polysaccharides,thus exerting numerous physiological functions.The extensive applications of Neu5Ac in the food,cosmetic,and pharmaceutical industries make large-scale production of this chemical desirable.Biosynthesis which is associated with important application potential and environmental friendliness has become an indispensable approach for large-scale synthesis of Neu5Ac.In this review,the physiological roles of Neu5Ac was first summarized in detail.Second,the safety evaluation,regulatory status,and applications of Neu5Ac were discussed.Third,enzyme-catalyzed preparation,whole-cell biocatalysis,and microbial de novo synthesis of Neu5Ac were comprehensively reviewed.In addition,we discussed the main challenges of Neu5Ac de novo biosynthesis,such as screening and engineering of key enzymes,identifying exporters of intermediates and Neu5Ac,and balancing cell growth and biosynthesis.The corresponding strategies and systematic strategies were proposed to overcome these challenges and facilitate Neu5Ac industrial-scale production.
基金the National Key Research and Development Program of China(2020YFA0908300)National Science Fund for Excellent Young Scholars(32222069)+2 种基金National Natural Science Foundation of China(32172349)Natural Science Foundation of Jiangsu Province(BK20200085)Key Research and Development Program of Jiangsu Province(BE2019628).
文摘N-acetylneuraminic acid(NeuAc)is an important nutrient that plays a key role in brain development in infants NeuAc is mainly produced by extraction from natural resources such as edible birds’s nests,crucian eggs,caviar and human breast milk.The extraction process is complicated,resulting in the disadvantages of low NeuAc content and low recovery rate.In this study,a crude enzyme immobilization-based cell-free system(CEICFS)was developed for efficient NeuAc biosynthesis.First,N-terminal coding sequences that improved the expression levels of N-acetylglucosamine-2-epimerase(AGE)and N-acetylneuraminic acid aldolase(NanA)were obtained by high-throughput screening.And these sequences resulted in up to 1.5-fold(1.2-fold)increase in AGE(NanA)enzyme levels.And then,a CEICFS for NeuAc biosynthesis was proposed by directly immobilizing crude enzyme containing AGE and NanA on amino resin.Subsequently,NeuAc production from GlcNAc using CEICFS in one reactor was carried out,resulting 68 g/L of NeuAc and the highest productivity of 6.8 g/L/h.Further,the enzyme activity was still higher than 75%after five repeated uses.The functional properties of CEICFS were studied and compared to those of the free enzyme,immobilization can extend the application of enzyme to some harsh environments,such as low temperature and acidic environment.Therefore,CEICFS with excellent heat resistance,storage stability and reusability exhibit great potential for industrial application.
基金the National Research Council,Bangkokthe Center of Excellent Found,Center of Excellence Viral Hepatitis Research Unit,Faculty of Medicine,Chulalongkom University+2 种基金the Thailand Research FundSenior Research Scholar(YP)Junior Research Scholar(PK)
文摘AIM:This study was designed to evaluate the clinical application of serum total sialic acid (TSA) in the diagnosis of cholangiocarcinoma (CCA).METHODS: Serum TSA was determined by periodateresorcinol microassay in 69 patients with CCA, 59 patients with hepatocellular carcinoma (HCC), 37 patients with cirrhosis, 61 patients with chronic hepatitis and 50 healthy blood donors.RESULTS: The mean serum TSA concentration in CCA (2.41±0.70 mmol/L) was significantly higher than those of HCC, cirrhosis, chronic hepatitis and healthy blood donors (1.41±0.37 mmol/L, 1.13±0.31 mmol/L, 1.16±0.26 mmol/L, and 1.10±0.14 mmol/L, respectively; P＜0.001). Based on ROC curve analysis, a cut-off point of 1.75 mmol/L discriminated between CCA and HCC with a sensitivity,specificity and accuracy of 82.6%, 83.1%, and 82.8%,respectively.CONCLUSION: Based on our results, serum TSA would be a useful marker for the differential diagnosis of CCA from HCC.
文摘AIM To investigate the bactericidal effects of calcium chelated N-acetylneuraminic acid-glycomacropeptide(CaG-NANA) against Helicobacter pylori(H.pylori).METHODS For manufacture of Ca G-NANA,calcium(Ca) was combined with glycomacropeptide(GMP) by chelating,and N-acetylneuraminic acid(NANA) was produced with Ca-GMP substrate by an enzymatic method.The final concentration of each component was 5% Ca,7% NANA,85% GMP,and 3% water.For in vitro study,various concentrations of CaG-NANA were investigated under the minimal inhibitory concentration(MIC).For in vivo study,Ca G-NANA was administered orally for 3 wk after H.pylori infection.The levels of inflamma-tory cytokines in blood were analyzed by enzyme-linked immunosorbent assay and eradication of H.pylori was assessed by histological observation.RESULTS The time-kill curves showed a persistent decrease in cellnumbers,which depended on the dose of CaG-NANA,and MIC of Ca G-NANA against H.pylori was 0.5% in vitro.Histopathologic observation revealed no obvious inflammation or pathologic changes in the gastric mucosa in the CaG-NANA treatment group in vivo.The colonization of H.pylori was reduced after CaG-NANA treatment.The levels of interleukin(IL)-6,IL-1β,tumor necrosis factor-α,and IL-10 were also decreased by CaG-NANA.CONCLUSION Ca G-NANA demonstrates effective anti-bactericidal activity against H.pylori both in vitro and in vivo.
基金This work was supported by the National Natural Science Foundation of China （No. 21205042）, the Daxia Foundation of East China Normal University （No. 2015DX-284） and the Students Innovative Experimental Project of Shanghai Municipality （No. 201610269070）. The authors have declared no conflicts of interest.
文摘Due to their important biological role as markers for different pathologies, sialic acid （SA） analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie detection （mini-CE-AD） was developed for the determination of N-aeetylneuraminic acid （NANA）, which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β-formyl pyruvic acid was derivatized with electroactive 2-thiobarbituric acid （TBA） to form an electroactive NANA-TBA adduct, which could be readily determined by mini-CE-AD. The limit of detection （LOD） of NANA-TBA could achieve 0.50 μg/mL （1.6 μmol·L-1, S/N=3） based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8%-109% with RSDs of 1.8%-3.9%. Due to its simple design and construction, low cost and portability, the mini-CE-AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.
