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@#Objective To develop and verify a whole column imaging detection-capillary isoelectric focusing(WCID-CIEF)method for the determination of isoelectric point(pI)of pertactin(PRN).Methods The WCID-CIEF method for the determination of PRN antigen was developed by optimizing the parameters such as the focusing time and final concentration of samples in the WCID-CIEF process,and verified for the specificity,accuracy,repeatability,intermediate precision,durability and inter-batch consistency.Results The optimal focusing time of WCID-CIEF for the determination of PRN antigen pI was 1 min at 1 500 V and 3 min at 3 000 V. The optimal final concentration of PRN antigen was 300 μg/mL. The PRN antigen pI was about 6. 035,and the blank matrix showed no interference peak in the position of each peak of antigen. The method had good specificity,accuracy,repeatability,intermediate precision,durability and consistency among batches.Conclusion The developed WCID-CIEF method is suitable for the pI detection and charge heterogeneity analysis of PRN antigen,which can provide basis for the characterization of PRN antigen and reference for the quality control in the process of development and production of related vaccines.
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@#Objective To compare the concentration and protein relative yield of insect fusion antifreeze protein EGFP-OcAFP4 extracted by low temperature ethanol method,ammonium sulfate salting-out method and isoelectric point method. Methods By screening different concentrations of ethanol(5%-65%)and ammonium sulfate(0. 2-3. 0 mol/L)and different the pH values(5. 6,5. 4,5. 2,5. 0,4. 8,4. 7,4. 6,4. 5,4. 4),EGFP-OcAFP4 was extracted from the supernatant of the induced expression solution of recombinant plasmid pET28a-EGFP-OcAFP4,and detected for the purity and protein relative yield.Results When prepared by ethanol method,EGFP-OCAFP4 had the highest purity of 86. 21% at the ethanol final concentration of 30%,and the relative yield was 6. 89%;when it was prepared by ammonium sulfate salting-out,the purity was up to 42. 33% with the protein relative yield of 30. 83% at the ammonium sulfate final concentration of 2. 0 mol/L;the purity of EGFP-OcAFP4 extracted by isoelectric point method with pH of 5. 0 was the highest 15. 46%,and the relative yield was 11. 97%. Conclusion Low temperature ethanol method,ammonium sulfate salting-out and isoelectric point method can all be used for the extraction of EGFP-OcAFP4,but low temperature ethanol method and ammonium sulfate salting-out method have higher extraction purity and protein relative yield,which are more suitable for the extraction of EGFP-OcAFP4
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@#Objective To establish and verify a capillary isoelectric focusing-whole column imaging detection(CIEFWCID) method for the analysis of isoelectric point(pI) of recombinant human brain natriuretic peptide.Methods The ampholyte,space-occupying agent,protein concentration,focusing time were optimized by CIEF-WCID method,and the best condition for the detection of recombinant human brain natriuretic peptide was obtained.The repeatability,precision and durability of the developed method were verified,and three batches of recombinant human brain natriuretic peptide produced continuously were analyzed for pI.Results HR AESlyte 8-10.5 was selected as ampholyte,while 25 mmol/L sodium hydroxide as the space-occupying agent;The final concentration of the sample was 87.5 μg/mL and the focusing time was 8min.The relative standard deviation RSD of pI detection was 0.1% after six consecutive injections of the same sample;The RSD of pI detection of six samples was 0.1%;The pI RSD of the main peak was 0.1% at different final concentrations of the sample,and the pI RSD of the sample was 0.1% at different storage time,while the pI markers could not be changed arbitrarily.The pI was detected in three consecutive batches of recombinant human brain natriuretic peptide samples.Conclusion The developed CIEF-WCID method for pI analysis of recombinant human brain natriuretic peptide had good repeatability and precision and might be used for follow-up quality control of recombinant human brain natriuretic peptide.
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OBJECTIVE: To analyze the glycosylated chains of recombinant interleukin-15 fusion protein using capillary isoelectric focusing-whole column imaging detection (WCID-cIEF) spectrograms. METHODS: Using established corresponding mathematical models and the least square method, the WCID-cIEF spectrograms of whole protein, de-salicylic-acid protein and de-N-glycosylation-chain protein were analyzed. Among the mathematical models, the interval-1-peak model was selected. And according to the model, the relationship between isoform peak-areas and isoelectric points was listed. RESULTS: The rationality of the interval-1-peak model was confirmed and a series of basic data was obtained according to the model as follows:the apparent m value of the protein was 25.53 reference(R), the apparent n value of the protein was 28.83R, the apparent m value of sialic acid was 0.86 (0.855) R, the apparent n value was 0.12 (0.119) R, the apparent n value of N-acetylglucosamine (undifferentiated from N-acetylgalactosamine) was 0.06(0.061) R, and the apparent m value of formed carboxyl after N-chain removal was 0.19 (0.186) R. Some information of protein sugar composition was also obtained: the sialylation degree was about 1.83 mol•mol-1, the percentage of prototype protein was about 8.3%, the percentage of single N-glycosated modification protein was about 19.8%, the percentage of double N-glycosated modification protein was about 28.4%, the percentage of triple N-glycosated modification protein was about 23.7%, and the percentage of O-glycosated modification (with sialic acid) protein was about 19.8%. The main sugar types should be G0 (F), G1 (F), G2 (F), G1A1 (F), and G2A1 (F). CONCLUSION: The structure of sugar chain is complex, but it also has some repeatability and regularity. We hope that through this study, the glycoprotein sugar chain can be quickly outlined, the understanding of glycoprotein and the study of protein interaction can be improved.
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OBJECTIVE: To detect and analyze the degree of salivary acidification of rhEPO isoforms. METHODS: The isoelectric points of rhEPO isoforms were determined with full column imaging capillary isoelectric focusing electrophoresis. And the charge distribution among rhEPO isoforms was analyzed. The degrees of rhEPO's total saliva acidification were measured using the method of appendices of Chinese Pharmacopoeia. At last, the degrees of saliva acidification of rhEPO isoforms were obtained using multivariate linear fitting. RESULTS: Nine kinds of rhEPO isoforms were distinguished and defined as isoform 1 to 9 with isoelectric points in the range of 3.6 to 5.1. There was one sialic acid molecule between two contiguous rhEPO isoform. Furthermore, the degrees of salivary acidification of the main four kinds of isoforms, 4-7, were 13, 12, 11 and 10 mol/mol, respectively. CONCLUSION :This study lays foundation for rhEPO biosimilar evaluation and further analysis of each isoform of rhEPO.
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Se ha buscado y seleccionado sistemáticamente una proteasa que pudiese ser usada en la eliminación "limpia" de encolantes sobre soportes documentales con valor de patrimonio histórico de forma eficiente y económica, a partir de la colección de hongos filamentosos del Archivo de Bogotá. De 74 morfotipos viables evaluados sobre placas selectivas, 32 morfotipos presentaron formación de halos de hidrólisis evidentes sobre placas diferenciales. De ellos, se evaluó el perfil isoenzimático de 8 morfotipos provenientes de muestreos documentales directos y de 2 morfotipos proteolíticos promisorios provenientes de un trabajo previo. Los 10 morfotipos seleccionados fueron representativos de los géneros Penicillium, Stachybotrys, Chaetomium, y Eladia. Luego de inducir la producción de proteasas extracelulares en medios líquidos diferenciales bajo tres fases de fermentación, se realizaron isoelectroénfoques analíticos tendientes a la observación de isoformas en el gradiente de pH establecido (3.0-10.0). Solo los morfotipos 8D (Chaetomium sp.) y 21D (Eladia saccula) presentaron una isoforma alcalina extrema, de puntos isoeléctricos 8.5 y 8.8, respectivamente, susceptible de selección con miras a su purificación y caracterización parcial de forma económica y eficiente. Los demás morfotipos, representativos de los géneros Penicillium sp., y Stachybotrys sp., presentaron unicamente isoformas proteolíticas en el rango acido de pH con puntos isoeléctricos que oscilan entre 4.0 y 5.0.
Studies on a protease as an efficient, environmental friendly and relatively economical remover of residual proteins for historical valuable documents were performed and was selected for this work, from the filamentous fungi collection of the Bogota Archive. 32 morphotypes of 74 evaluated show hydrolytic activities over differential solid media. From them, 8 morphotypes obtained directly from documental samples and representative of the genera Penicillium and Stachybotrys were selected and their isoenzyme profile were tested. Also 2 previous morphotypes with promisorius proteolytic activities and representative of the genera Chaetomium and Eladia were analysed. Extracelullar proteases production was induced in differential liquid media on three fermentation steps and analitycal isoelectrofocusing were performed over pH 3.0-10.0 ranges. Only the morphotypes 8D (Chaetomium sp.), and 21D (Eladia sp.), showed an alkaline isoform with pIs 8.5 and 8.8, respectly, suceptible of selection for its purification and characterization through efficient and economical way. The others morphotypes only showed acid isoforms with pIs in the range of 4.0 and 5.0.
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Biodegradação Ambiental , Chaetomium , Ponto Isoelétrico , Papel , Penicillium , Stachybotrys , Fermentação , ArquivamentoRESUMO
Antifreeze proteins (AFPs) protect organisms from freezing and shows great diversity in structure, and they have been found in a variety of organisms. In this study, a total of 15 antifreeze proteins of fish were selected where they represent distinct physicochemical and structural features. The present paper uses bioinformatics approach to describe the physiochemical, functional and structural properties of Antifreeze proteins. Several Physico-chemical properties such as pI, EC, AI, GRAVY and instability index are computed and provide data about these proteins and their properties. The result of primary structure analysis infers that, fish antifreeze proteins are mostly hydrophobic. Disulfide bridges and secondary structures were analyzed using CYS_REC and SOPMA respectively. The three dimensional structure of Antifreeze proteins is predicted by using three homology modeling server Geno3D, Swiss-model and CPHmodels. The model was evaluated with PROCHECK, WHAT IF, and ProSA programs. Model visualization and analysis was done with Pymol. These structures will provide a good foundation for functional analysis of experimentally derived crystal structures.
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Antifreeze proteins (AFPs) protect organisms from freezing and shows great diversity in structure, and they have been found in a variety of organisms. In this study, a total of 15 antifreeze proteins of fish were selected where they represent distinct physicochemical and structural features. The present paper uses bioinformatics approach to describe the physiochemical, functional and structural properties of Antifreeze proteins. Several Physico-chemical properties such as pI, EC, AI, GRAVY and instability index are computed and provide data about these proteins and their properties. The result of primary structure analysis infers that, fish antifreeze proteins are mostly hydrophobic. Disulfide bridges and secondary structures were analyzed using CYS_REC and SOPMA respectively. The three dimensional structure of Antifreeze proteins is predicted by using three homology modeling server Geno3D, Swiss-model and CPHmodels. The model was evaluated with PROCHECK, WHAT IF, and ProSA programs. Model visualization and analysis was done with Pymol. These structures will provide a good foundation for functional analysis of experimentally derived crystal structures.
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Extended spectrum β-lactamases (ESBLs) have been observed in virtually all the species of family Enterobacteriaceae. Threat posed by antibiotic resistance because of ESBLs is more serious as a number of technical problems are associated with the detection of these enzymes. Although a number of detection methods have been designed for ESBLs, every method has its own benefits and shortcomings as well. In earlier days, isoelectric focusing (IEF) was used as the gold standard for ESBL detection. This study was undertaken to compare IEF with polymerase chain reaction, a method which has been extensively used for ESBL detection these days.
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The existence of microheterogeneity of glucose-6-phosphate dehydrogenase(G6PD)in the human erythrocyt has already been reported(Der Kaloustian 1974).The results has been confirmed recently by isoelectric focusing in polyacrylamide gel.In this paper,we used the method which has been modified in some aspects to identify various G6PD variants,and came to interesting conclusions.We provide here our experimental data of two different G6PD types,GdB and Gd(-)Zhuang-Funing,Focusing of the enzyme gives additional in- formation concerning an accurate distinction among the genetic variants.