The application of MS in newborn screening is one of the most important branches of MSs current clinical application. In this paper we first reported a new method of newborn screening for Phenylketonuria (PKU) by GC...The application of MS in newborn screening is one of the most important branches of MSs current clinical application. In this paper we first reported a new method of newborn screening for Phenylketonuria (PKU) by GC-CI-MS-SIM, which was relatively cheap, fast, sensitive and accurate. In this method Phenylalanine (Phe) and Tyrosine (Tyr) were extracted from dry blood spots with 0.1% mol/L HCl-methanol. The protein in the extraction was gotten rid of by centrifugor. Phe and Tyr were reacted with 3 0 mol/L HCl-butanol, then the products Phe and Tyr butyl esters were reacted with trifluoroacetic anhydride. The final derivations from Phe and Tyr, alanine, 3-phenyl-N-(trifluoroacetyl)-, butyl este and L-tyrosine, N(trifluoroacetyl)-, butyl ester, trifl were analyzed by GC-CI-MS-SIM. The contents of the two amino acids in blood samples were determined by calculating the areas of their final derivations with exterior standard. Finally, the molar ratios of Phe to Tyr in blood sample were calculated as the basis of PKU diagnosis. Because chemical ionization and selective ion measurement were used in this method, the limits of detection for Phe and Tyr were low and the sensitivity was excellent. About 30 blood samples were analyzed by this method, and the results prove that this method could successfully discriminate between normal infants and PKU positive ones. The price of instrument GC-MS is cheaper than that of MS-MS. Therefore it was capable for large-scale screening in developing countries.展开更多
The membrane trafficking of cation-independent mannose 6-phosphate receptor（CI-M6PR） between the transGolgi network（TGN） and endosomal compartments is not only critical for maintaining lysosomal function but also ...The membrane trafficking of cation-independent mannose 6-phosphate receptor（CI-M6PR） between the transGolgi network（TGN） and endosomal compartments is not only critical for maintaining lysosomal function but also a well-known event for understanding molecular and cellular mechanisms in retrograde endosome-to-TGN trafficking.Although it has been well established in literature that the C-terminus of bovine CI-M6PR determines its retrograde trafficking,it remains unclear whether the luminal domain of the protein plays a role on these sorting events.In this study,we found that partial deletion of luminal domain of human CI-M6PR mistargeted the mutant protein to nonTGN compartments.Moreover,replacing the luminal domain of both bovine and human CI-M6PR with that from irrelevant membrane proteins such as CD8 or Tac also altered the TGN targeting of the chimeric proteins.On the other hand,only short sequence from HA fused with the transmembrane domain and C-terminus of the receptor,HA-hCIM6PR-tail,resulted in its preferential targeting to TGN as for the full length receptor,strongly suggesting that sorting of the receptor may be influenced by luminal sequence.Furthermore,using this luminal truncated form of HA-hCIM6 PR as a model cargo,we found that the trafficking of the chimeric protein was regulated by the retromer complex through interacting with SNX5.In conclusion,our study strongly suggested that the disrupted luminal domain from hCI-M6PR or other irrelevant membrane proteins interfere with the process of membrane trafficking and TGN targeting of CI-M6PR.展开更多
采用柱色谱和阴离子交换树脂法分离渣油馏分中的羧酸,通过红外光谱仪检验分离出的羧酸类型。将石油酸和异丁烷反应气引入到离子源进行化学电离(CI)—质谱(MS)法分析,这些离子可以用来计算石油酸的相对分子质量。以纯脂肪酸、环烷酸以及...采用柱色谱和阴离子交换树脂法分离渣油馏分中的羧酸,通过红外光谱仪检验分离出的羧酸类型。将石油酸和异丁烷反应气引入到离子源进行化学电离(CI)—质谱(MS)法分析,这些离子可以用来计算石油酸的相对分子质量。以纯脂肪酸、环烷酸以及分离出的石油酸的 CI 质谱数据为基础,并结合环烷酸 z 系列通式 C_nH_(2n+z)O_2分别得到了不同碳数的脂肪酸、一环、二环……六环环烷酸的分析结果。结果表明,渣油中的羧酸主要是环烷酸,相对分子质量分布在198～540,碳数分布在 C_(12)～C_(37),其中三环、四环环烷酸含量较高。展开更多
Naphthenic acids in petroleum are considered a class of biological markers. Their potential use in source correlation and as an indicator of biodegradation was reported in the past (Dzidic et al., 1988; Behar and Albr...Naphthenic acids in petroleum are considered a class of biological markers. Their potential use in source correlation and as an indicator of biodegradation was reported in the past (Dzidic et al., 1988; Behar and Albrecht, 1984). Due to their highly complicated properties, detailed characterization of the acids is difficult. A method based on positive ion CI (chemical ionization) mass spectrometry using isobutane reagent gas to produce (M+15)++ ions was applied to the analysis of naphthenic acid esters. Since the complex mixture of naphthenic acids cannot be separated into individual components, only the determination of relative distribution of acids classified in terms of hydrogen deficiency was possible. The identities and relative distribution of fatty and mono-, di-, tri-, and higher polycyclic acids were obtained from the intensities of the (M+15)++ ions according to z-series formula C-nH-{2n+z}O-2 of naphthenic acids. The components are characterized on the basis of group type and carbon number distributions. A comparison of the FAB and CI results showed that the group type distributions obtained by both methods agree surprisingly well. The results indicated this method is simple, rapid and easy to operate. The geochemical implication of naphthenic acids was investigated by using a set of well-characterized crude oil samples. It is found that the naphthenic acid distribution can be used as a fingerprint for oil-oil and oil-source correlations.展开更多
The petroleum acids in crude oil were separated by extraction with column chromatogram and anion exchange resin. The separation effect and the related composition and structure of petroleum acids were obtained by usin...The petroleum acids in crude oil were separated by extraction with column chromatogram and anion exchange resin. The separation effect and the related composition and structure of petroleum acids were obtained by using IR (Infra-Red) spectra techniques. The separated petroleum acids can under special conditions react with methanol to form corresponding esters, which can be analyzed by CI (chemical ionization)-MS (mass spectrometry). The characteristic ion peaks m/z (M+15)+ of naphthenic acid esters combined with z-series formula CnH2n+zO2 of naphthenic acids can be used to classify naphthenic acids into fatty acids, mono-cyclic, bi-cyclic, tri-cyclic, and higher polycyclic acids. The analytical results can give the molecular weight and the carbon number distribution of petroleum acids contained in crude oil. The results of study indicate that this method is simple, rapid and easy in operation.展开更多
文摘The application of MS in newborn screening is one of the most important branches of MSs current clinical application. In this paper we first reported a new method of newborn screening for Phenylketonuria (PKU) by GC-CI-MS-SIM, which was relatively cheap, fast, sensitive and accurate. In this method Phenylalanine (Phe) and Tyrosine (Tyr) were extracted from dry blood spots with 0.1% mol/L HCl-methanol. The protein in the extraction was gotten rid of by centrifugor. Phe and Tyr were reacted with 3 0 mol/L HCl-butanol, then the products Phe and Tyr butyl esters were reacted with trifluoroacetic anhydride. The final derivations from Phe and Tyr, alanine, 3-phenyl-N-(trifluoroacetyl)-, butyl este and L-tyrosine, N(trifluoroacetyl)-, butyl ester, trifl were analyzed by GC-CI-MS-SIM. The contents of the two amino acids in blood samples were determined by calculating the areas of their final derivations with exterior standard. Finally, the molar ratios of Phe to Tyr in blood sample were calculated as the basis of PKU diagnosis. Because chemical ionization and selective ion measurement were used in this method, the limits of detection for Phe and Tyr were low and the sensitivity was excellent. About 30 blood samples were analyzed by this method, and the results prove that this method could successfully discriminate between normal infants and PKU positive ones. The price of instrument GC-MS is cheaper than that of MS-MS. Therefore it was capable for large-scale screening in developing countries.
基金supported by the National Nature Science Foundation of China to Y.Liu(Grant No.31371436 and No.8157051134)Y.Huang(Grant No.81500678)the laboratory start-up grant from Nanjing Medical University to Y.Liu
文摘The membrane trafficking of cation-independent mannose 6-phosphate receptor（CI-M6PR） between the transGolgi network（TGN） and endosomal compartments is not only critical for maintaining lysosomal function but also a well-known event for understanding molecular and cellular mechanisms in retrograde endosome-to-TGN trafficking.Although it has been well established in literature that the C-terminus of bovine CI-M6PR determines its retrograde trafficking,it remains unclear whether the luminal domain of the protein plays a role on these sorting events.In this study,we found that partial deletion of luminal domain of human CI-M6PR mistargeted the mutant protein to nonTGN compartments.Moreover,replacing the luminal domain of both bovine and human CI-M6PR with that from irrelevant membrane proteins such as CD8 or Tac also altered the TGN targeting of the chimeric proteins.On the other hand,only short sequence from HA fused with the transmembrane domain and C-terminus of the receptor,HA-hCIM6PR-tail,resulted in its preferential targeting to TGN as for the full length receptor,strongly suggesting that sorting of the receptor may be influenced by luminal sequence.Furthermore,using this luminal truncated form of HA-hCIM6 PR as a model cargo,we found that the trafficking of the chimeric protein was regulated by the retromer complex through interacting with SNX5.In conclusion,our study strongly suggested that the disrupted luminal domain from hCI-M6PR or other irrelevant membrane proteins interfere with the process of membrane trafficking and TGN targeting of CI-M6PR.
文摘采用柱色谱和阴离子交换树脂法分离渣油馏分中的羧酸,通过红外光谱仪检验分离出的羧酸类型。将石油酸和异丁烷反应气引入到离子源进行化学电离(CI)—质谱(MS)法分析,这些离子可以用来计算石油酸的相对分子质量。以纯脂肪酸、环烷酸以及分离出的石油酸的 CI 质谱数据为基础,并结合环烷酸 z 系列通式 C_nH_(2n+z)O_2分别得到了不同碳数的脂肪酸、一环、二环……六环环烷酸的分析结果。结果表明,渣油中的羧酸主要是环烷酸,相对分子质量分布在198～540,碳数分布在 C_(12)～C_(37),其中三环、四环环烷酸含量较高。
文摘Naphthenic acids in petroleum are considered a class of biological markers. Their potential use in source correlation and as an indicator of biodegradation was reported in the past (Dzidic et al., 1988; Behar and Albrecht, 1984). Due to their highly complicated properties, detailed characterization of the acids is difficult. A method based on positive ion CI (chemical ionization) mass spectrometry using isobutane reagent gas to produce (M+15)++ ions was applied to the analysis of naphthenic acid esters. Since the complex mixture of naphthenic acids cannot be separated into individual components, only the determination of relative distribution of acids classified in terms of hydrogen deficiency was possible. The identities and relative distribution of fatty and mono-, di-, tri-, and higher polycyclic acids were obtained from the intensities of the (M+15)++ ions according to z-series formula C-nH-{2n+z}O-2 of naphthenic acids. The components are characterized on the basis of group type and carbon number distributions. A comparison of the FAB and CI results showed that the group type distributions obtained by both methods agree surprisingly well. The results indicated this method is simple, rapid and easy to operate. The geochemical implication of naphthenic acids was investigated by using a set of well-characterized crude oil samples. It is found that the naphthenic acid distribution can be used as a fingerprint for oil-oil and oil-source correlations.
文摘The petroleum acids in crude oil were separated by extraction with column chromatogram and anion exchange resin. The separation effect and the related composition and structure of petroleum acids were obtained by using IR (Infra-Red) spectra techniques. The separated petroleum acids can under special conditions react with methanol to form corresponding esters, which can be analyzed by CI (chemical ionization)-MS (mass spectrometry). The characteristic ion peaks m/z (M+15)+ of naphthenic acid esters combined with z-series formula CnH2n+zO2 of naphthenic acids can be used to classify naphthenic acids into fatty acids, mono-cyclic, bi-cyclic, tri-cyclic, and higher polycyclic acids. The analytical results can give the molecular weight and the carbon number distribution of petroleum acids contained in crude oil. The results of study indicate that this method is simple, rapid and easy in operation.
