AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.ME...AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.METHODS： Rats were given 1 mL of 75% ethanol, 25%NaCl, 0.6 mol/L HCI, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically （i.g.） and sacrificed 1, 3, 6 or 12 min later. Total （reduced and oxidized） glutathione （GSH ＋ GSSG）, glutathione disulfide （GSSG）, protein free sulfhydryls （PSH）, protein-glutathione mixed disulfides （PSSG） and protein cystine disulfides （PSSP） were measured in gastric mucosa and liver.RESULTS： Reduced glutathione （GSH） was depleted in the gastric mucosa after ethanol, HCI or NaCl exposure,while oxidized glutathione （GSSG） concentrations increased, except by HCI and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed,NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all chemicals.No changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.CONCLUSION： Our modified methods are now suitable for direct measurements of major protein and nonprotein thiols/disulfides in the gastric mucosa or liver.A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.展开更多
A method for the synthesis of diaryl sulfides from aryl halides in polyethylene glycol was reported.Inodorous Na2S2O3·5H2O,which is readily available as a stable salt,is an effective source of sulfur in the prese...A method for the synthesis of diaryl sulfides from aryl halides in polyethylene glycol was reported.Inodorous Na2S2O3·5H2O,which is readily available as a stable salt,is an effective source of sulfur in the presence of Cu I as catalyst.展开更多
Fe（NO3）3-9H2O/Fe（HSO4）3 was used as an efficient reagent system for the oxidation of alcohols to their corresponding carbonyl compounds. All reactions were performed in the absence of solvent in good to high yield...Fe（NO3）3-9H2O/Fe（HSO4）3 was used as an efficient reagent system for the oxidation of alcohols to their corresponding carbonyl compounds. All reactions were performed in the absence of solvent in good to high yields. Under the same reaction conditions, thiols and sulfides were also converted to their corresponding disulfides and sulfoxides, respectively. 2007 Farhad Shirini. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid....The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid. The dispersions can be transformed into corresponding redispersible powder via a spray dryingcooling process. On-line FT-IR monitoring shows that grafting polymer of PVA-g-PMMA was formed mainly at the stage-1 of the emulsion polymerization. TEM images show, the PVA-SH shell was fragmentary when adding SDS at initial stage and integrated when adding at particle growing or final stage. The particle size turns to be smaller when delayed adding SDS surfactant. Triethanolamine, a co-regulator of PVA-SH, controlled the M to 50 000-70 000 and reduced the PDI to 1.5-1.7. The acrylic dispersions with 0.8wt%-1.5wt% PVA-SH1 can be spray-dried into super dispersible polymer powder （SDPP）, which can easily disperse in water and form recon- stituted dispersions with an average particle size smaller than 1 micron.展开更多
The thiol components of the nonhistone proteins prepared from isolated nuclei from rat liver, regenerating liver and hepatoma 223 cells have been investigated after reaction with radio labelled N-ethylmaleimide and 5-...The thiol components of the nonhistone proteins prepared from isolated nuclei from rat liver, regenerating liver and hepatoma 223 cells have been investigated after reaction with radio labelled N-ethylmaleimide and 5-5’-dithiobis-(2-nitrobenzoic acid) (DTNB). The labelled adducts formed were examined by isoelectric focusing analysis in polyacrylamide gel and the distribution of the radiolabels within sliced portions of the gels determined. In the case of the 14C labelled NEM adduct the label was found to be spread amongst numerous protein components within the gel however, in the case of the 35S labelled DTNB adducts, only a small proportion of the label was found in the protein material which was retained in the acidic isoelectric point (pI) region of the gel. The bulk of the 35S labelled adduct (56% - 60%) was found to have migrated into the anode solution (10 mM phosphoric acid). This could be adsorbed onto a hydrophobic resin (XAD2) resin and eluted with methanol. Gel filtration chromatographic analysis of this adduct material on BioGel P2, (exclusion limit 1500 daltons) showed low molecular weight components to be present. Slightly different patterns were obtained for these nuclei, each containing several 35S components with molecular weights greater than the Ellman reagent itself. These 35S labelled thiol components did not contain any protein, peptide or amino acid components indicating strongly that a novel species of thiols could be present in these nuclei bound within the non-histone protein matrices.展开更多
A Michael addition is usually taken as a base-catalysed reaction. However, our synthesized 2-（quinolin-2-ylmethylene） malonic acid （QMA） as a Michael-type thiol fluorescent probe is acid-active in its sensing reac...A Michael addition is usually taken as a base-catalysed reaction. However, our synthesized 2-（quinolin-2-ylmethylene） malonic acid （QMA） as a Michael-type thiol fluorescent probe is acid-active in its sensing reaction. In this work, based on theoretic calculation and experimental study on 7-hydroxy-2-（quinolin-2-ylmethylene） malonic acid, we demonstrated that QMA as a Michael acceptor is acid-activatable, i.e., it works only in solutions at pH〈7, and the lower the pH of solutions is, the higher reactivity QMA has. In alkaline solution, the malonate QMA[-2H＋]2- cannot react with both RSand RSH. In contrast, 2-（quinolin-2- ylmethylene） malonic ester （QME）, the ester of QMA, reveal a contrary pH effect on its sensing reaction, that is, it can sense thiols in alkaline solutions but not in acidic solutions, like a normal base-catalysed Michael addition. The values of activation enthalpies from theoretic calculation support the above sensing behavior of two probes under different pH conditions. In acidic solutions, the protonated QMA is more highly reactive towards electrophilic attack over its other ionized states in neutral and alkaline solutions, and so can react with lowly reactive RSH. In contrast, there is a big energy barrier in the interaction of QME with RSH （acidic solutions）, and the reaction of QME with the highly reactive nucleophile RS- is a low activation energy process （in alkaline solutions）. Theoretic calculation reveals that the sensing reaction of QMA undergoes a 1,4-addition process with neutral thiols （RSH）, and a 1,2-addition pathway for the sensing reaction of QME with RS-. Therefore, the sensing reaction of QMA is an acid-catalysed Michael addition via a 1,4-addition, and a normal base-catalysed Michael addition via a 1,2-addition.展开更多
In this paper, a thiol-functionalized nanophotocatalyst MPTES/TiO2 was first synthesized by one-pot method using P123 as a template. X-ray diffraction confirms the complete anatase crystalline of thiol-functionalized ...In this paper, a thiol-functionalized nanophotocatalyst MPTES/TiO2 was first synthesized by one-pot method using P123 as a template. X-ray diffraction confirms the complete anatase crystalline of thiol-functionalized TiO2, N2 adsorption-desorption isotherm demonstrated that these materials possess high surface area and mesoporous structure. The results of XPS show that MPTES has been successfully polymerized in mesoporous structured TiO2. The photodegradation of phenanthrene （PHE） was investigated under visible light irradiation （λ 〉 420 nm） to evaluate the photocatalytic activity of these materials. Based the experiment results of GC-Mass analysis, a possible mechanism was proposed.展开更多
Standard reference material and different geological samples were dissolved by system A (the mixture of nitric and perchloric acids) and system B (mixture of nitric, perchloric and hydrofluoric acids), and total Se in...Standard reference material and different geological samples were dissolved by system A (the mixture of nitric and perchloric acids) and system B (mixture of nitric, perchloric and hydrofluoric acids), and total Se in all samples was measured by hydride-generation atomic fluorescence spectrometry (HG-AFS) after concentration with thiol cotton fiber (TCF). The analytical results obtained by the two digestion method are in good agreement (within the limit of errors) for most of the samples, particularly for those having recommended values. The Se concentrations determined by the two methods are of no difference, and the correlation coefficient is 0.9986; the relative standard deviation (RSD) for the determination of 0.04 μg/g Se is 10.2%. The recovery rates of systems A and B by the stan- dard-addition method were 96%–106% and 99%–104%, respectively.展开更多
The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our c...The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our calculations show that oligosilanes doped by the phenyl and -C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage （I-V） curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra.展开更多
Introduction Polymers containing thiol and sulphoxide which have active—SH and—SO groups respectively, have wide application to biological, pharmaceutical, industrial and other chemical field and—SH and—SO groups ...Introduction Polymers containing thiol and sulphoxide which have active—SH and—SO groups respectively, have wide application to biological, pharmaceutical, industrial and other chemical field and—SH and—SO groups are easy to form complexes with metals, so they have aroused an increasing interest of many authors. A large number of functional resins and corresponding metal complexes have been synthesized.展开更多
A 2a-phenylthio ether analog 1c of docetaxel was synthesized for the first time from 10-deacetylbaccatin III 3 via double inversion of C-2 configuration. This compound showed very weak cytotoxicity toward several tumo...A 2a-phenylthio ether analog 1c of docetaxel was synthesized for the first time from 10-deacetylbaccatin III 3 via double inversion of C-2 configuration. This compound showed very weak cytotoxicity toward several tumor cell lines.展开更多
The low molecular weight thiols present in the deproteinized extract of a prostate cancer cell line (LNCaP-FGC) were analysed after derivatization with the Ellman reagent (ESSE). The mixed disulphides formed (RSSE) we...The low molecular weight thiols present in the deproteinized extract of a prostate cancer cell line (LNCaP-FGC) were analysed after derivatization with the Ellman reagent (ESSE). The mixed disulphides formed (RSSE) were fractionated, characterized and quantified by liquid chromatography on a C-18 column using UV detection. This revealed the presence, in femtomoles per cell, of glutathione (8.30 ± 0.73), cysteine (2.71 ± 0.04) and cysteinylglycine (0.83 ± 0.10), accounting for the bulk of the thiol present. Further analysis of the cell extracts using a novel and sensitive mass spectrometry technique allowed the detection of low level of an additional derivative which was identified as cysteinylglycerate using NMRspectroscopy.展开更多
Self-assembled monolayers of octadecanethiol (ODT) on gold have been studied by electrochemical impedance spectroscopy (EIS). The fractional coverage has been examined as a function of immersion time of Au in ODT depo...Self-assembled monolayers of octadecanethiol (ODT) on gold have been studied by electrochemical impedance spectroscopy (EIS). The fractional coverage has been examined as a function of immersion time of Au in ODT deposition solution. The fractional coverage exhibits two distinct adsorption steps: an initial rapid step followed by a slow one. The fractional coverage of ODT monolayer increases sharply from zero to more than 99% of its maximum within the first minute. However. it takes a day for the fractional coverage to approach its final value.展开更多
A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotid...A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.展开更多
In this paper, we used resonance light\|scatter i ng (RLS) spectroscopy to study the interaction between thiol\|containing pharmac eutical and gold colloid. And for the first time, we proposed that this highly s ensit...In this paper, we used resonance light\|scatter i ng (RLS) spectroscopy to study the interaction between thiol\|containing pharmac eutical and gold colloid. And for the first time, we proposed that this highly s ensitive, gold colloid\|based assay using RLS technique may have potential appli cation in detecting thiol\|containing substances.展开更多
文摘AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.METHODS： Rats were given 1 mL of 75% ethanol, 25%NaCl, 0.6 mol/L HCI, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically （i.g.） and sacrificed 1, 3, 6 or 12 min later. Total （reduced and oxidized） glutathione （GSH ＋ GSSG）, glutathione disulfide （GSSG）, protein free sulfhydryls （PSH）, protein-glutathione mixed disulfides （PSSG） and protein cystine disulfides （PSSP） were measured in gastric mucosa and liver.RESULTS： Reduced glutathione （GSH） was depleted in the gastric mucosa after ethanol, HCI or NaCl exposure,while oxidized glutathione （GSSG） concentrations increased, except by HCI and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed,NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all chemicals.No changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.CONCLUSION： Our modified methods are now suitable for direct measurements of major protein and nonprotein thiols/disulfides in the gastric mucosa or liver.A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.
基金the Persian Gulf University Research Council for generous partial financial support of this study
文摘A method for the synthesis of diaryl sulfides from aryl halides in polyethylene glycol was reported.Inodorous Na2S2O3·5H2O,which is readily available as a stable salt,is an effective source of sulfur in the presence of Cu I as catalyst.
文摘Fe（NO3）3-9H2O/Fe（HSO4）3 was used as an efficient reagent system for the oxidation of alcohols to their corresponding carbonyl compounds. All reactions were performed in the absence of solvent in good to high yields. Under the same reaction conditions, thiols and sulfides were also converted to their corresponding disulfides and sulfoxides, respectively. 2007 Farhad Shirini. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid. The dispersions can be transformed into corresponding redispersible powder via a spray dryingcooling process. On-line FT-IR monitoring shows that grafting polymer of PVA-g-PMMA was formed mainly at the stage-1 of the emulsion polymerization. TEM images show, the PVA-SH shell was fragmentary when adding SDS at initial stage and integrated when adding at particle growing or final stage. The particle size turns to be smaller when delayed adding SDS surfactant. Triethanolamine, a co-regulator of PVA-SH, controlled the M to 50 000-70 000 and reduced the PDI to 1.5-1.7. The acrylic dispersions with 0.8wt%-1.5wt% PVA-SH1 can be spray-dried into super dispersible polymer powder （SDPP）, which can easily disperse in water and form recon- stituted dispersions with an average particle size smaller than 1 micron.
文摘The thiol components of the nonhistone proteins prepared from isolated nuclei from rat liver, regenerating liver and hepatoma 223 cells have been investigated after reaction with radio labelled N-ethylmaleimide and 5-5’-dithiobis-(2-nitrobenzoic acid) (DTNB). The labelled adducts formed were examined by isoelectric focusing analysis in polyacrylamide gel and the distribution of the radiolabels within sliced portions of the gels determined. In the case of the 14C labelled NEM adduct the label was found to be spread amongst numerous protein components within the gel however, in the case of the 35S labelled DTNB adducts, only a small proportion of the label was found in the protein material which was retained in the acidic isoelectric point (pI) region of the gel. The bulk of the 35S labelled adduct (56% - 60%) was found to have migrated into the anode solution (10 mM phosphoric acid). This could be adsorbed onto a hydrophobic resin (XAD2) resin and eluted with methanol. Gel filtration chromatographic analysis of this adduct material on BioGel P2, (exclusion limit 1500 daltons) showed low molecular weight components to be present. Slightly different patterns were obtained for these nuclei, each containing several 35S components with molecular weights greater than the Ellman reagent itself. These 35S labelled thiol components did not contain any protein, peptide or amino acid components indicating strongly that a novel species of thiols could be present in these nuclei bound within the non-histone protein matrices.
基金This work is supported by the National Natural Science Foundation of China （No.21272224）, the Open Research Fund of State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University （No.201410）, and the Open Research Fund of Key Laboratory of Advanced Scientific Computation, Xihua University （No.szjj2013-024）.
文摘A Michael addition is usually taken as a base-catalysed reaction. However, our synthesized 2-（quinolin-2-ylmethylene） malonic acid （QMA） as a Michael-type thiol fluorescent probe is acid-active in its sensing reaction. In this work, based on theoretic calculation and experimental study on 7-hydroxy-2-（quinolin-2-ylmethylene） malonic acid, we demonstrated that QMA as a Michael acceptor is acid-activatable, i.e., it works only in solutions at pH〈7, and the lower the pH of solutions is, the higher reactivity QMA has. In alkaline solution, the malonate QMA[-2H＋]2- cannot react with both RSand RSH. In contrast, 2-（quinolin-2- ylmethylene） malonic ester （QME）, the ester of QMA, reveal a contrary pH effect on its sensing reaction, that is, it can sense thiols in alkaline solutions but not in acidic solutions, like a normal base-catalysed Michael addition. The values of activation enthalpies from theoretic calculation support the above sensing behavior of two probes under different pH conditions. In acidic solutions, the protonated QMA is more highly reactive towards electrophilic attack over its other ionized states in neutral and alkaline solutions, and so can react with lowly reactive RSH. In contrast, there is a big energy barrier in the interaction of QME with RSH （acidic solutions）, and the reaction of QME with the highly reactive nucleophile RS- is a low activation energy process （in alkaline solutions）. Theoretic calculation reveals that the sensing reaction of QMA undergoes a 1,4-addition process with neutral thiols （RSH）, and a 1,2-addition pathway for the sensing reaction of QME with RS-. Therefore, the sensing reaction of QMA is an acid-catalysed Michael addition via a 1,4-addition, and a normal base-catalysed Michael addition via a 1,2-addition.
基金support from NBRP of China(No.973:2007CB613301)along with No. 2008AA06Z327 from the 863 Program of the MSTC,NNSF of China(No.20773601,20873059,50732004 and 20871067)JSPNSF(No.BE2008126)+1 种基金JSPEPBP(No.2008005)the SRFGS of Nanjing University(No.CX08B- 009)from JSPI for PhD candidate and Analysis Center of Nanjing University
文摘In this paper, a thiol-functionalized nanophotocatalyst MPTES/TiO2 was first synthesized by one-pot method using P123 as a template. X-ray diffraction confirms the complete anatase crystalline of thiol-functionalized TiO2, N2 adsorption-desorption isotherm demonstrated that these materials possess high surface area and mesoporous structure. The results of XPS show that MPTES has been successfully polymerized in mesoporous structured TiO2. The photodegradation of phenanthrene （PHE） was investigated under visible light irradiation （λ 〉 420 nm） to evaluate the photocatalytic activity of these materials. Based the experiment results of GC-Mass analysis, a possible mechanism was proposed.
基金the Knowledge-Innovation Program of the Chinese Academy of Sciences（KZCX3-SW-125）；the National Natural Science Foundation of China（Grant Nos.60633110,40003008）.
文摘Standard reference material and different geological samples were dissolved by system A (the mixture of nitric and perchloric acids) and system B (mixture of nitric, perchloric and hydrofluoric acids), and total Se in all samples was measured by hydride-generation atomic fluorescence spectrometry (HG-AFS) after concentration with thiol cotton fiber (TCF). The analytical results obtained by the two digestion method are in good agreement (within the limit of errors) for most of the samples, particularly for those having recommended values. The Se concentrations determined by the two methods are of no difference, and the correlation coefficient is 0.9986; the relative standard deviation (RSD) for the determination of 0.04 μg/g Se is 10.2%. The recovery rates of systems A and B by the stan- dard-addition method were 96%–106% and 99%–104%, respectively.
基金supported by National Natural Science Foundation of China(21401023 and 21203027)Cultivating Fund for Excellent Young Scholar of Fujian Normal University(FJSDJK2012063)Program for Innovative Research Team in Science and Technology in Fujian Province University(IRTSTFJ)
文摘The electron transport properties of various molecular junctions based on the thiol-ended oligosilane are investigated through density functional theory combined with non-equilibrium Green＇s function formalism. Our calculations show that oligosilanes doped by the phenyl and -C10H6 groups demonstrate better rectifying effect and their rectification ratios are up to 15.41 and 65.13 for their molecular junctions. The current-voltage （I-V） curves of all the Au/ modified oligosilane/Au systems in this work are illustrated by frontier molecular orbitals, transmission spectra and density of states under zero bias. And their rectifying behaviors are analyzed through transmission spectra.
基金Supported by the National Natural Science Foundation of China
文摘Introduction Polymers containing thiol and sulphoxide which have active—SH and—SO groups respectively, have wide application to biological, pharmaceutical, industrial and other chemical field and—SH and—SO groups are easy to form complexes with metals, so they have aroused an increasing interest of many authors. A large number of functional resins and corresponding metal complexes have been synthesized.
基金Financial support from Funding to Outstanding Doctor Thesis Authors of Chinese Universities (Grant No. 199949) is gratefully acknowledged by W. S. Fang.
文摘A 2a-phenylthio ether analog 1c of docetaxel was synthesized for the first time from 10-deacetylbaccatin III 3 via double inversion of C-2 configuration. This compound showed very weak cytotoxicity toward several tumor cell lines.
文摘The low molecular weight thiols present in the deproteinized extract of a prostate cancer cell line (LNCaP-FGC) were analysed after derivatization with the Ellman reagent (ESSE). The mixed disulphides formed (RSSE) were fractionated, characterized and quantified by liquid chromatography on a C-18 column using UV detection. This revealed the presence, in femtomoles per cell, of glutathione (8.30 ± 0.73), cysteine (2.71 ± 0.04) and cysteinylglycine (0.83 ± 0.10), accounting for the bulk of the thiol present. Further analysis of the cell extracts using a novel and sensitive mass spectrometry technique allowed the detection of low level of an additional derivative which was identified as cysteinylglycerate using NMRspectroscopy.
基金the Natural Science Foundation of Hebei Province.
文摘Self-assembled monolayers of octadecanethiol (ODT) on gold have been studied by electrochemical impedance spectroscopy (EIS). The fractional coverage has been examined as a function of immersion time of Au in ODT deposition solution. The fractional coverage exhibits two distinct adsorption steps: an initial rapid step followed by a slow one. The fractional coverage of ODT monolayer increases sharply from zero to more than 99% of its maximum within the first minute. However. it takes a day for the fractional coverage to approach its final value.
基金Supported by Prime Minister FouNdationthe High Techriology Research and Development Programme of ChinaRockefeller Foun-dation.
文摘A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.
文摘In this paper, we used resonance light\|scatter i ng (RLS) spectroscopy to study the interaction between thiol\|containing pharmac eutical and gold colloid. And for the first time, we proposed that this highly s ensitive, gold colloid\|based assay using RLS technique may have potential appli cation in detecting thiol\|containing substances.
