In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoan...In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoantibodies to hnRNPs have been reported in patients suffering from different rheumatic dieseases since 1980s. Experimental evidence indicates that hnRNP complexes undergo substantial structural changes during mRNA formation and export. However, how this contributes to disease development still has to be elucidated. Here some preliminary physicochemical features of RNA-protein folding and stability patterns of newly characterized hnRNP A3 with further functional implications in development of systemic human autoimmune states are reported.展开更多
Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by t...Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.展开更多
Understanding aquatic pathogen in sediments or aquacultural water is crucial to protect public health from soilborne and waterborne diseases.Quorum sensing(QS)was increasingly reported in biological wastewater treatme...Understanding aquatic pathogen in sediments or aquacultural water is crucial to protect public health from soilborne and waterborne diseases.Quorum sensing(QS)was increasingly reported in biological wastewater treatment processes because of their inherent roles in biofilm development,bacterial aggregation and so on.The widely QS signals was Antoinducer-2(AI-2),primarily involved to allow the possibility of interspecies communication.However,the cellular components that mediate the response of Streptococcus agalactiae to AI-2 have not been fully characterized.Analysis of the complete genome sequence of S.agalactiae indi-cated that its RbsB protein has similarity to Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2.We hypothesized that RbsB protein mediates quorum sensing signal uptake via interaction with AI-2.To evaluate the regulatory effect of RbsB on QS system,the recombinant plasmid pGEX-6p-1-RbsB was constructed and RbsB protein was purified with GST-tag.To further elucidate the role of RbsB protein binding to DPD(AI-2 precursor dihydroxypentanedione),the systemati-cally throughput circular dichroism(CD)spectroscopy,isothermal titration calorimetry200(ITC200)and molecular docking methods were employed.The high expression of soluble RbsB protein with molecular weight of 33 kDa was obtained.The thermodynamics results(ΔH<0,ΔS<0,ΔG<0)with ITC determination indicated that the binding process between DPD and RbsB was exothermic and spontaneous,with hydrogen bonds and van der Waals forces as the main binding forces.Obviously,DPD can be more easily combined with RbsB in a dose-dependent manner,suggesting that RbsB was changed in the microenvironment of DPD when the DPD concentration was between 0.8-1.0mmolL−1 and reaching the maximum binding amount.According to molecular docking,3 hydrophobic residues involved in DPD and RbsB protein stable binding were be found,and also hydrogen bonding plays a key role in the formation of the new complex.RbsB efficiently inhibited V.harveyi bioluminescence induced by both S.agalactiae AI-2 and V.harveyi AI-2 in a dose-dependent manner.However,our results suggest that RbsB may play a role in the response of S.agalactiace to AI-2.展开更多
The chaperone-like huntingtin-interacting protein, HYPK, has unusual biophysical behavior like an intrinsically unstructured protein (IUP). The protein exists as a (pre-) molten globule with ~37% residual structure an...The chaperone-like huntingtin-interacting protein, HYPK, has unusual biophysical behavior like an intrinsically unstructured protein (IUP). The protein exists as a (pre-) molten globule with ~37% residual structure and shows com- paction in presence of Ca++. HYPK contains no intrinsic fluorophore other than a single tyrosine and displays an anomalous fluorescence peak at around 340 nm. The anomalous peak is re- duced to 303 nm by the addition of guanidine hydrochloride and at low pH, concomitant with the emission spectrum of L-tyrosine. At high pH the peak is shifted to ~350 nm with a reduction in intensity. In presence of sodium perchlorate there is no shift in HYPK fluorescence emission peak from ~340 nm suggesting localization of the lone tyrosine residue in helical regions. In CD experiments, however, a shift in local secondary structure is noticed upon perchlorate treatment. Acrylamide quenching experiments at different Ca++ concentrations demonstrate that Ca++ does not alter the accessibility of the tyro- sine to acrylamide. In the absence of any tryp- tophan contamination, these observations vali- date that, in vitro, HYPK possesses a loosely associated (pre-) molten globule like conforma- tion with the lone tyrosine being situated within an α-helix.展开更多
采用Lowery法、ANS荧光探针法、圆二色光谱、荧光光谱等方法分别对不同辐照处理的红豆分离蛋白溶解度、表面疏水性、蛋白质二级、三级结构、流体动力学半径进行分析。结果表明:随着辐照剂量的增加,红豆分离蛋白的二级结构中α-螺旋结构...采用Lowery法、ANS荧光探针法、圆二色光谱、荧光光谱等方法分别对不同辐照处理的红豆分离蛋白溶解度、表面疏水性、蛋白质二级、三级结构、流体动力学半径进行分析。结果表明:随着辐照剂量的增加,红豆分离蛋白的二级结构中α-螺旋结构向无规则卷曲结构的转变,Trp残基所处微环境极性先增强后减弱,这与其表面疏水性呈现正相关,蛋白颗粒大小随着辐照剂量的增加先减小后增大,在5 k Gy辐照剂量处理时达到最小,这与其溶解性呈现负相关。展开更多
文摘In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoantibodies to hnRNPs have been reported in patients suffering from different rheumatic dieseases since 1980s. Experimental evidence indicates that hnRNP complexes undergo substantial structural changes during mRNA formation and export. However, how this contributes to disease development still has to be elucidated. Here some preliminary physicochemical features of RNA-protein folding and stability patterns of newly characterized hnRNP A3 with further functional implications in development of systemic human autoimmune states are reported.
文摘Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.
基金This study was supported by the National Natural Sci-ence Foundation of China(Nos.31702386,31660251,31860245 and 31960203)the International Cooperation Science&Technology Planning Project of Guangdong Province of China(No.2017A050501037)+2 种基金the Natural Science Foundation of Guangxi Province(Nos.2018 GXNSFAA281019,2017GXNSFAA198010)the Central Government Directs Special Funds for Local Science and Technology Development Projects(No.ZY1949015)E.Wangkahart was supported financially by the Ministry of Science and Technology of Thailand and Mahasarakham University.
文摘Understanding aquatic pathogen in sediments or aquacultural water is crucial to protect public health from soilborne and waterborne diseases.Quorum sensing(QS)was increasingly reported in biological wastewater treatment processes because of their inherent roles in biofilm development,bacterial aggregation and so on.The widely QS signals was Antoinducer-2(AI-2),primarily involved to allow the possibility of interspecies communication.However,the cellular components that mediate the response of Streptococcus agalactiae to AI-2 have not been fully characterized.Analysis of the complete genome sequence of S.agalactiae indi-cated that its RbsB protein has similarity to Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2.We hypothesized that RbsB protein mediates quorum sensing signal uptake via interaction with AI-2.To evaluate the regulatory effect of RbsB on QS system,the recombinant plasmid pGEX-6p-1-RbsB was constructed and RbsB protein was purified with GST-tag.To further elucidate the role of RbsB protein binding to DPD(AI-2 precursor dihydroxypentanedione),the systemati-cally throughput circular dichroism(CD)spectroscopy,isothermal titration calorimetry200(ITC200)and molecular docking methods were employed.The high expression of soluble RbsB protein with molecular weight of 33 kDa was obtained.The thermodynamics results(ΔH<0,ΔS<0,ΔG<0)with ITC determination indicated that the binding process between DPD and RbsB was exothermic and spontaneous,with hydrogen bonds and van der Waals forces as the main binding forces.Obviously,DPD can be more easily combined with RbsB in a dose-dependent manner,suggesting that RbsB was changed in the microenvironment of DPD when the DPD concentration was between 0.8-1.0mmolL−1 and reaching the maximum binding amount.According to molecular docking,3 hydrophobic residues involved in DPD and RbsB protein stable binding were be found,and also hydrogen bonding plays a key role in the formation of the new complex.RbsB efficiently inhibited V.harveyi bioluminescence induced by both S.agalactiae AI-2 and V.harveyi AI-2 in a dose-dependent manner.However,our results suggest that RbsB may play a role in the response of S.agalactiace to AI-2.
文摘The chaperone-like huntingtin-interacting protein, HYPK, has unusual biophysical behavior like an intrinsically unstructured protein (IUP). The protein exists as a (pre-) molten globule with ~37% residual structure and shows com- paction in presence of Ca++. HYPK contains no intrinsic fluorophore other than a single tyrosine and displays an anomalous fluorescence peak at around 340 nm. The anomalous peak is re- duced to 303 nm by the addition of guanidine hydrochloride and at low pH, concomitant with the emission spectrum of L-tyrosine. At high pH the peak is shifted to ~350 nm with a reduction in intensity. In presence of sodium perchlorate there is no shift in HYPK fluorescence emission peak from ~340 nm suggesting localization of the lone tyrosine residue in helical regions. In CD experiments, however, a shift in local secondary structure is noticed upon perchlorate treatment. Acrylamide quenching experiments at different Ca++ concentrations demonstrate that Ca++ does not alter the accessibility of the tyro- sine to acrylamide. In the absence of any tryp- tophan contamination, these observations vali- date that, in vitro, HYPK possesses a loosely associated (pre-) molten globule like conforma- tion with the lone tyrosine being situated within an α-helix.
文摘采用Lowery法、ANS荧光探针法、圆二色光谱、荧光光谱等方法分别对不同辐照处理的红豆分离蛋白溶解度、表面疏水性、蛋白质二级、三级结构、流体动力学半径进行分析。结果表明:随着辐照剂量的增加,红豆分离蛋白的二级结构中α-螺旋结构向无规则卷曲结构的转变,Trp残基所处微环境极性先增强后减弱,这与其表面疏水性呈现正相关,蛋白颗粒大小随着辐照剂量的增加先减小后增大,在5 k Gy辐照剂量处理时达到最小,这与其溶解性呈现负相关。
