Development and verification of kinetic chromogenic quantitative detection method for endotoxin content in intermediate of component pertussis antigen / 中国生物制品学杂志

@#Objective To develop a kinetic chromogenic quantitative method for the determination of endotoxin content in intermediate of pertussis antigen,and to verify the method so as to better control the quality of diphtheria,tetanus,and pertussis vaccine(DTP vaccine).Methods A kinetic chromogenic assay[Limulus Amebocyte Lysate(LAL)]was developed to detect the endotoxin content in the intermediate products of pertussis antigens after detoxification,and verified for the linearity,specificity,accuracy,reproducibility and intermediate precision. The quantitative detection results of kinetic chromogenic assay were compared with those of gel method.Results The absolute value of the linear correlation coefficient（|r|）of the kinetic chromogenic assay was more than 0. 99;under the maximum effective multiple dilution,the interference test recovery of the intermediate was within 50% — 200%,and pertussis toxin(PT)diluted to 10,100 and 1 000 times,filamentous hemagglutinin(FHA)diluted to 3 000,5 000 and 10 000 times,and pertussis adhesin(PRN)diluted to 50,75 and 100 times had no interference effect on the experiment after detoxification;the accuracy verification recovery rates of PT,FHA and PRN were 125%,110% and 99% respectively;and the CVs of reproducibility verification were 7. 21%,8. 31% and 5. 84%,and the CVs of intermediate precision verification were 6. 04%,16. 29% and 12. 23%,respectively.The bacterial endotoxin content of the three batches of pertussis antigen intermediates detected by kinetic chromogenic assay was consistent with that verified by gel method,both of which were less than the limit of bacterial endotoxin in the intermediates of pertussis antigen after detoxification.Conclusion The developed kinetic chromogenic assay has good linearity,specificity,accuracy and precision with accurate detection results,which can be used to detect the endotoxin content in intermediate products of component pertussis antigen after detoxification.

The Influence of Morphological Characteristics on the Ball Throwing Velocity in the Professional Handball Players / Influencia de las Características Morfológicas en la Velocidad de Lanzamiento del Balón en los Jugadores Profesionales de Balonmano

SUMMARY: The aim of this study was to determine influence of upper limbs on the ball throwing velocity. A total of 10 professional handball players (25.74±4.84 years) participated in this study. All of them were playing in the top Montenegrin professional handball league. The results obtained in this study shows that upper limbs have high influence on ball throwing velocity. This study provides normative data and performance standards for professional handball. Coaches can use this information to determine the type of anthropometric characteristics that are needed for handball. Anthropometric parameters such as arm length, wrist diameter, hand length and arm span are the most relevant aspects related to ball throwing speed, given that these parameters cannot be changed through training, they should be taken into account when discovering talents.

El objetivo de este estudio fue determinar la influencia de los miembros superiores sobre la velocidad de lanzamiento de la pelota. En el estudio participaron un total de 10 jugadores profesionales de balonmano (25,74±4,84 años). Todos ellos jugaban en la principal liga profesional de balonmano de Montenegro. Los resultados obtenidos mostraron que los miembros superiores tienen una alta influencia en la velocidad de lanzamiento de la pelota. Este estudio proporciona datos normativos y estándares de rendimiento para el balonmano profesional. Los entrenadores pueden utilizar esta información para determinar el tipo de características antropométricas necesarias para el balonmano. Los parámetros antropométricos como la longitud del brazo, el diámetro de la muñeca, la longitud de la mano y la envergadura del brazo son los aspectos más relevantes relacionados con la velocidad de lanzamiento de la pelota, dado que estos parámetros no se pueden cambiar mediante el entrenamiento, deben tenerse en consideración a la hora de descubrir talentos.

Desenvolvimento de compostos de coordenação para aplicação foliar e elucidação do mecanismo de absorção / Development of coordination compounds for foliar application and elucidation of the absorption mechanism

O objetivo geral desse trabalho foi desenvolver compostos de coordenação com os metais cobre, manganês, zinco, cobalto, níquel e magnésio com os aminoácidos L- ácido aspártico e glutâmico para aplicação como fertilizantes foliares e elucidação de seus prováveis mecanismos de absorção pela planta. Como plano de trabalho, pretendeu-se produzir alguns complexos metálicos com agentes complexantes que confiram características específicas: alta estabilidade termodinâmica e cinética quando comparado a quelatos usados comercialmente dos mesmos metais; alta solubilidade; compatibilidade com herbicidas e fungicidas e alta estabilidade frente a variações de pH. Os compostos foram caracterizados no estado sólido e/ou em solução aquosa, através de técnicas disponíveis em nosso laboratório, na Central Analítica do IQ-USP e/ou nos laboratórios da ICL América do Sul Ind. e Com. SA. Com o desenvolvimento dos compostos de coordenação, foram avaliados alguns parâmetros considerados imprescindíveis para garantia da qualidade do produto gerado, que foram então comparados aos de quelatos de EDTA (ácido etilenodiaminotetraacético) comercializados atualmente e que demonstraram vantagens. Para avaliar a eficiência dos produtos gerados foi realizada aplicação foliar em ao menos uma cultura e verificado o teor de cada nutriente após período de absorção e resposta produtiva, evidenciando e determinando o mecanismo de absorção realizado pela planta. Como resultado, desenvolveu-se uma série de produtos com alta tecnologia agregada que trouxeram benefícios nutricionais, sustentando uma nutrição de qualidade além de serem ecologicamente favoráveis (eco-friendly portfolio)

This project aims the development of copper, manganese, zinc, cobalt, nickel and iron metal complexes with L-amino acids aspartic and glutamic acids for application as foliar fertilizers and elucidation of the probable incorporation/absorption mechanism by plants. As a work plan, it was intended to produce these metal complexes with complexing agents that provide specific characteristics: high thermodynamic and kinetic stabilities when compared to the corresponding EDTA chelates; high solubility; compatibility with herbicides and fungicides and high stability against pH variations. With the development of such coordination compounds, some parameters considered indispensable to quality assurance were then evaluated, in comparison to that of currently available commercial EDTA chelates. To evaluate the performance of the obtained compounds, two foliar applications in the same crop were carried out. Further, the content of each nutrient after the production period and the productive capacity were evaluated, aiming to elucidate the absorption mechanism of the plant. As a result, elaborated products with high added technology were obtained, capable of ameliorating the nutritional benefits, that can support an eco-friendly portfolio

Solid-state properties of pink clay from Jequitinhonha Valley in Brazil for pre-formulation study

Abstract Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) hematite, Fe2+, and Fe3+ with large Δ/2ξq of about 2.80 and 2.69 mm.s-1 respectively, related to iron silicates, most likely pyroxene, and a superparamagnetic Fe3+. Pink clay exhibits poor flow properties. The thermal behavior indicates a phase-transition between 400 - 600 ºC associated with the dehydroxylation of the pink clay system requiring ~300 kJ mol-1, being constant until the process reaches a conversion of ~50% when the energy is enhanced to ~530 kJ mol-1, concluding the whole dehydroxylation process (α=80%). Solid-state properties and characteristics found for the pink clay must be considered for the proper design of formulations. This type of clay shows unique pharmaceutical properties that can be favorably exploited by the cosmetic industry

The advance of ω-transaminase in chiral amine biosynthesis in China from the perspective of patents / 生物工程学报

ω-transaminases are able to catalyze the reversible transfer of amino groups between diverse amino compounds (such as amino acids, alkyl amines, aromatic amines) and carbonyl compounds (such as aldehydes, ketones, ketoacids). ω-transaminases exhibit great application prospects in the field of chiral amine biosynthesis because of their desirable properties, such as wide range of substrates, high stereoselectivity, and mild catalytic conditions. It is therefore important for China to develop efficient, specific, and environment-friendly chiral amine production technologies with independent intellectual property rights, which is of great significance for the development of pharmaceutical, pesticide, and material industries. This review systematically summarizes the Chinese patents regarding ω-transaminase filed by Chinese institutions in the recent decade. The development of ω-transaminase resource, enzymatic property improvement by protein engineering, application in chiral amine synthesis, and development of production technologies are elaborated. This review will shed light on further basic and application studies of ω-transaminase.

Influence of selection of domain shape on parameters of microdosimetric kinetic model / 中华放射医学与防护杂志

Objective:To calculate the single-event dose-averaged specific energy of particles delivered in spherical domains based on the track structure model and using triple integration, and to investigate the influence of the domain shape on the key model parameters of microdosimetric kinetic model (MKM) and its corresponding physical significance.Methods:The domains are assumed to be cylinders and spheres, respectively. With α 0, domain radius, rd, and nucleus radius, Rn, as undetermined coefficients, the nuclear charge numbers, kinetic energies and their corresponding LETs of three kinds of charged particles ( 3He, 12C, 20Ne) as independent variables, D10 as dependent variable, the mean value of squared residuals, J2, between the D10 calculated values and D10 experimental values as the optimization objective, the final fitting values of the above undetermined coefficients of human salivary gland (HSG) cells and Chinese hamster lung (V79) cells obtained after iteration by the robust least square method are the optimal model parameter values of MKM. Results:For HSG cells, cylindrical domain: α 0=0.073/Gy, rd=0.29 μm, Rn=4.1 μm, J2=0.039 7 Gy 2; spherical domain: α 0=0.023/Gy, rd=0.29 μm, Rn=4.4 μm, J2=0.039 3 Gy 2; For V79 cells, cylindrical domain: α 0=0.114/Gy, rd=0.25 μm, Rn=3.8 μm, J2=0.097 4 Gy 2; spherical domain: α 0=0.095/Gy, rd=0.26 μm, Rn=4.1 μm, J2=0.096 9 Gy 2. Conclusions:For the same type of cells, cylindrical and spherical domains were selected respectively, and there are significant differences in MKM parameters obtained by fitting. The fitting values of the domain radius, rd of the two shapes of domains show no significant difference, while the fitting values of α0 of spherical domains are smaller than those of cylindrical domains, the fitting values of nucleus radius, Rn, of spherical domain are larger than those of cylindrical domains, closer to the nucleus radius observed by fluorescence microscopy. In the low LET (<20 keV/μm) region, D10 calculated according to the parameters of the two different shapes of domains are different, so the selection of the domain shape will cause differences in the relative biological effectiveness(RBE) calculation of proton in the region near Bragg peak.

The Regulation of Expression and Activity of Glucose Transporter 1 / 中国生物化学与分子生物学报

Glucose transporters (GLUTs) encoded by the solute carrier family 2 (SLC2) gene belong to the major facilitator superfamily (MFS) and are responsible for the transmembrane transport of glucose in the body. As the earliest discovered member of the GLUTs, glucose transporter 1 (GLUT1) is mainly found in the blood-brain barrier and erythrocyte membrane, and plays an important role in maintaining stable blood glucose concentration and energy supply to the brain. The transmembrane transport capacity of GLUT1 is not only related to the gene expression of SLC2 A1 on the cellular membrane, but also to the transport kinetic regulation of GLUT1. Generally, SLC2 A1 expression is regulated at the transcriptional, post-transcriptional, translational and post-translational levels, and the transport kinetics regulation includes a series of GLUT1 inhibitors, such as intramembrane glycan-binding site inhibitor, extramembrane glycan-binding site inhibitor, adenosine-binding effect inhibitors and the highly selective inhibitor BAY-876. SLC2 A1 gene deletions and mutations can cause embryonic mortality and GLUT1 deficiency syndrome. In contrast, abnormally high SLC2 A1 expression is associated with various diabetic complications (e. g. diabetic retinopathy and diabetic nephropathy), neurocognitive impairment and tumorigenesis. In this paper, the structure, function, expression and activity regulation of GLUT1 and its relationship with diseases were reviewed to provide a reference for the GLUT1-related clinical research and drug development.

Studies on Impact of Processing on Physiochemical and Biochemical Properties of Osmodehydrated Pineapple (Ananas comosus (L) Merr.) Cuboid and Its Storage Stability

Osmotic dehydration of pineapple cuboids were conducted to study the effect of sugar concentration of osmotic solution on mass transfer, weight reduction, vitamin-C, total phenol content and antioxidant property of samples pretreated with steam blanching and microwave heating. As treatment time went on, there was an increase in water loss, weight loss, and solids accumulation. The sample treated with 60°B experienced the highest mass transfer during the osmotic dehydration of pineapple cuboids, whereas the sample treated with 30°B experienced the lowest mass transfer. The pineapple cuboids immersed in 60˚B sugar syrup and dried in a tray drier resulted maximum weight loss. Microwave heated samples dipped in 60˚B sugar syrup showed better retention of nutritive value(total phenol content, vitamin C and antioxidant activity) as well as better color, texture, taste and mouth feel .According to the sensory analysis, the samples treated with 60°B solution received the highest acceptability for color, flavour, texture, mouth feel, and taste. Osmodried samples were stored for 3 months at ambient condition without any adverse effect on sensory and nutritional parameters.

Decolorization of the benzidine-based azo dye Congo red by the new strain Shewanella xiamenensis G5-03 / Descoloração do corante azo derivado da benzidina vermelho Congo por uma nova linhagem de Shewanella xiamenensis G5-03

Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the Michaelis­Menten model (Vmax = 111.11 mg L-1 h-1 and Km = 448.3 mg L-1). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.

Shewanella xiamenensis G5-03 foi capaz de descolorir o corante azo vermelho Congo em água residuária sintética. A influência de alguns fatores na eficiência da descoloração do corante foi avaliada. As condições ótimas de descoloração foram temperatura de 30-35 °C, pH 10,0 e condições estáticas. A cinética de descoloração do vermelho Congo se ajustou ao modelo de Michaelis­Menten (Vmax = 111,11 mg L-1 h-1 and Km = 448,3 mg L-1). A bactéria também foi capaz de degradar a benzidina, um produto da quebra da ligação azo do vermelho Congo, o que contribuiu para a redução da fitotoxicidade. A habilidade da S. xiamenensis G5-03 em simultaneamente descolorir e degradar o vermelho Congo demostra seu potencial de aplicação no tratamento de águas residuárias contendo corantes azo.

Study on equivalence between micro kinetic chromogenic assay and kinetic chromogenic assay / 中国药理学通报

Aim To evaluate the equivalence between micro kinetic chromogenic assay anrl kinetic chromogenic assay in order to provide data support for the use of alternative methods.Methods Detection conditions; micro kinetic chromogenic assay and kinetic chromogenic assay limulus reagent were used, sample amount of each well and limulus reagent was 25 jxL ( kinetic chromogenic assay was 100 jxL) , detection wavelength was 405 nm, ONSET OD value was 0.03, and half- well elisa plate was used for detection ( kinetic chromogenic assay was ordinary ELISA plate).The equivalence of the two methods was evaluated by various statistical methods, such as equivalence test, in collaboration with four laboratories in China.Results The results of one-way an OVA, paired T test and equivalence test were consistent, indicating that there were some differences between the existing kinetic chromogenic assay of different manufacturers, while there was no significant difference between the trace or conventional amount of reagent used by each manufacturer.Conclusions Micro kinetic chromogenic assay is e- quivalent to existing reagents in terms of accuracy and recoverv.J.

Study on bacterial endotoxin detection of egg yolk lecithin of Chinese Pharmacopoeia 2020 Edition / 中国药理学通报

Abstract; Aim To solve the problems in the appliea- tion of egg yolk leeithin endotoxin test method, and and to establish the baeterial endotoxin examination method for egg yolk lecithin (for injeetion). Methods The ethanol solution of Tween 80 ( the volume ratio of tween 80 to anhydrous ethanol was 2. 5 • 2. 7, mixed for 4 min) was used to prepare lecithin solution of egg yolk at 0. 1 kg • L 1 , and 10 test water was added to 1 mL lecithin solution of egg yolk (500 EU • mL 1 standard solution of endotoxin IOjxL was added for pos¬itive control). After diluted 20 times with endotoxin test water, the standard curve range was 10 ~0. 01 EU • mL 1 by kinetic-turbidimetrie assay. Methodology of endotoxin test was studied using limulus lysate from two manufacturers and eight hatches of samples. Results The recoveries of eight hatches of samples all met the requirement of interference test between 50% and 200% stipulated in the pharmacopoeia, which solved the problems of the current endotoxin test method in practical application. Conclusions The bacterial en¬dotoxin test method of egg yolk lecithin with good dura-bility is established to provide the basis for the revision of pharmacopoeia.

Decolorization of the benzidine-based azo dye Congo red by the new strain Shewanella xiamenensis G5-03 / Descoloração do corante azo derivado da benzidina vermelho Congo por uma nova linhagem de Shewanella xiamenensis G5-03

Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the Michaelis–Menten model (Vmax = 111.11 mg L-¹ h-¹ and Km = 448.3 mg L-¹). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.

Shewanella xiamenensis G5-03 foi capaz de descolorir o corante azo vermelho Congo em água residuária sintética. A influência de alguns fatores na eficiência da descoloração do corante foi avaliada. As condições ótimas de descoloração foram temperatura de 30-35 °C, pH 10,0 e condições estáticas. A cinética de descoloração do vermelho Congo se ajustou ao modelo de Michaelis–Menten (Vmax = 111,11 mg L-¹ h-¹ and Km = 448,3 mg L-¹). A bactéria também foi capaz de degradar a benzidina, um produto da quebra da ligação azo do vermelho Congo, o que contribuiu para a redução da fitotoxicidade. A habilidade da S. xiamenensis G5-03 em simultaneamente descolorir e degradar o vermelho Congo demostra seu potencial de aplicação no tratamento de águas residuárias contendo corantes azo.

Decolorization of the benzidine-based azo dye Congo red by the new strain Shewanella xiamenensis G5-03

Abstract Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the MichaelisMenten model (Vmax = 111.11 mg L-1 h-1 and Km = 448.3 mg L-1). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.

Resumo Shewanella xiamenensis G5-03 foi capaz de descolorir o corante azo vermelho Congo em água residuária sintética. A influência de alguns fatores na eficiência da descoloração do corante foi avaliada. As condições ótimas de descoloração foram temperatura de 30-35 °C, pH 10,0 e condições estáticas. A cinética de descoloração do vermelho Congo se ajustou ao modelo de MichaelisMenten (Vmax = 111,11 mg L-1 h-1 and Km = 448,3 mg L-1). A bactéria também foi capaz de degradar a benzidina, um produto da quebra da ligação azo do vermelho Congo, o que contribuiu para a redução da fitotoxicidade. A habilidade da S. xiamenensis G5-03 em simultaneamente descolorir e degradar o vermelho Congo demostra seu potencial de aplicação no tratamento de águas residuárias contendo corantes azo.

Momento aductor de la cadera durante la marcha en adultos mayores asintomáticos / Hip adductor moment during gait in asymptomatic older adults

Resumen Introducción: El momento articular durante la marcha se ha relacionado con diferentes procesos clínicos en la población adulto mayor, en Colombia no se cuentan con reportes propios. Objetivo: Analizar el momento aductor de la cadera durante la marcha de adultos mayores asintomáticos. Materiales y métodos: Se evaluó a 110 participantes siguiendo las referencias del software VICON NEXUS 2.8.1 modelo Full Body, se utilizó 2 plataformas de fuerza y el volumen de captura estuvo delimitado por 8 cámaras opto eléctricas Bonita 10. Se incluyó variables antropométricas, sociodemográficas, espaciotemporales y cinéticas durante la fase de apoyo, resaltando los dos picos máximos del momento aductor. Resultados: Las cifras del Pico Momento Aductor 1 y 2 (PMA1 y PMA2) fueron de 0,76 y 0,70 Nm/Kg respectivamente, estos picos se relacionaron con masa, talla e índice de masa corporal. Se construyó así una referencia para el análisis de adultos mayores asintomáticos. Conclusiones: La gráfica del momento aductor de la cadera es similar a la descrita por otros investigadores, pero en menor magnitud que en la población sintomática de coxartrosis.

Abstract Introduction: Although joint moment during waking has been associated with different clinical processes in the elderly population, there is a lack of reports in Colombia. Objective: To analyze the hip adductor moment during gait in asymptomatic older adults. Materials and methods: 110 participants were assessed using the VICON NEXUS 2.8.1. Full Body model software. 2 force platforms were used and the capture volume was delimited through 8 Bonita-10 optoelectronic cameras. Anthropometric, sociodemographic, spatiotemporal, and kinetic variables were included during the support phase, highlighting the two maximum peaks of the adductor moment. Results: The figures for Adductor Moment Peaks 1 and 2 (AMP1 and AMP2) were 0.76 and 0.70 Nm/Kg, respectively, which were related to mass, height and body mass index. Thus, a reference for the analysis of asymptomatic older adults was developed. Conclusion: The hip adductor moment graph is similar to that described by other researchers, but to a lesser extent than the values seen in coxarthrosis symptomatic population.

Production, characterization and kinetic model of biosurfactant produced by lactic acid bacteria

BACKGROUND Biosurfactants are surface active molecules produced by microorganisms which have the ability to disrupt the plasma membrane. Biosurfactant properties are important in the food, pharmaceu tical and oil industries. Lactic acid bacteria can produce cell-bound and excreted biosurfactants. RESULTS The biosurfactant-producing ability of three Lactobacillus strains was analyzed, and the effects of carbon and nitrogen sources and aeration conditions were studied. The three species of lactobacillus eval uated were able to produce biosurfactants in anaerobic conditions, which was measured as the capacity of one extract to reduce the surface tension compared to a control. The decreasing order of biosurfactant production was L. plantarum>Lactobacillus sp.>L. acidophilus. Lactose was a better carbon source than glu cose, achieving a 23.8% reduction in surface tension versus 12.9% for glucose. Two complex nitrogen sources are required for growth and biosurfactant production. The maximum production was reached at 48 h under stationary conditions. However, the highest level of production occurred in the exponential phase. Biosurfactant exhibits a critical micelle concentration of 0.359 ± 0.001 g/L and a low toxicity against E. coli. Fourier transform infrared spectroscopy indicated a glycoprotein structure. Additionally, the kinetics of fermentation were modeled using a logistic model for the biomass and the product, achieving a good fit (R2 > 0.9). CONCLUSIONS L. plantarum derived biosurfactant production was enhanced using adequate carbon and nitrogen sources, the biosurfactant is complex in structure and because of its low toxicity could be applied to enhance cell permeability in E. coli

Potential application of a knowledgebase of iron metabolism of Acidithiobacillus ferrooxidans as an alternative platform

BACKGROUND: Acidithiobacillus ferrooxidans is a facultative anaerobe that depends on ferrous ion oxidation as well as reduced sulfur oxidation to obtain energy and is widely applied in metallurgy, environmental protection, and soil remediation. With the accumulation of experimental data, metabolic mechanisms, kinetic models, and several databases have been established. However, scattered data are not conducive to understanding A. ferrooxidans that necessitates updated information informed by systems biology. RESULTS: Here, we constructed a knowledgebase of iron metabolism of A. ferrooxidans (KIMAf) system by integrating public databases and reviewing the literature, including the database of bioleaching substrates (DBS), the database of bioleaching metallic ion-related proteins (MIRP), the A. ferrooxidans bioinformation database (Af-info), and the database for dynamics model of bioleaching (DDMB). The DBS and MIRP incorporate common bioleaching substrates and metal ion-related proteins. Af-info and DDMB integrate nucleotide, gene, protein, and kinetic model information. Statistical analysis was performed to elucidate the distribution of isolated A. ferrooxidans strains, evolutionary and metabolic advances, and the development of bioleaching models. CONCLUSIONS: This comprehensive system provides researchers with a platform of available iron metabolism-related resources of A. ferrooxidans and facilitates its application.

Study on extraction kinetics of Salviae Miltiorrhizae Radix et Rhizoma: model establishment and investigation of critical process parameters / 中国中药杂志

In this study, Fick's first law and partition equilibrium were used to represent the internal and external mass transfer processes of Salviae Miltiorrhizae Radix et Rhizoma at the macroscopic level, and a mass transfer model was established. The specific surface area was integrated into the mass transfer resistance, which effectively avoided the irregular shape of medicinal materials and expanded the application scope of the model. Meanwhile, the mass transfer model was further combined with the kinetic model of salvia-nolic acid degradation to establish the extraction kinetic models of salvianolic acid B, lithospermic acid and Danshensu. The model was applied to study the extraction process of Salviae Miltiorrhizae Radix et Rhizoma. According to the sensitivity analysis results, the relative error of the model prediction was within 5% near the maximum extraction rate(320 min), and the prediction performance of the model was good. According to the investigation results of different process parameters, stirring could significantly accelerate the mass transfer rate of salvianolic acid B, while the mass transfer resistance and degradation rate constant were not affected by solvent-to-solid ratio. The linear relationship between the reciprocal of temperature and the logarithm of mass transfer resistance was good(R~2=0.996), indicating that the temperature and mass transfer resistance conformed to Arrhenius formula. In addition, we also found that the concentration changes of lithospermic acid and Danshensu were weakly affected by mass transferwhen the extraction temperature was higher than 358 K. This study has provided the basis for the process optimization and quality control of traditional Chinese medicine extraction.

Production of lactate from carbon fixation by cyanobacteria: development and prospect / 生物工程学报

Lactate is an important industrial chemical and widely used in various industries. In recent years, with the increasing demand for polylactic acid (PLA), the demand for lactate raw materials is also increasing. The contradiction between the high cost and the market demand caused by the heterotrophic production of lactate attracts researchers to seek other favorable solutions. The production of lactate from photosynthetic carbon fixation by cyanobacteria is a potential new raw material supply strategy. Based on the photosynthetic autotrophic cell factory, it can directly produce high optical purity lactate from carbon dioxide on a single platform driven by solar energy. The raw materials are cheap and easy to obtain, the process is simple and controllable, the products are clear and easy to separate, and the double effects of energy saving and emission reduction and production of high value-added products are achieved at the same time, which has important research and application value. This paper reviews the development history of cyanobacteria carbon sequestration to produce lactate, summarizes its research progress and encounters technical difficulties from the aspects of metabolic basis, metabolic engineering strategy, metabolic kinetics analysis and technical application, and prospects the future of this technology.

Glycosylation of ß1 subunit plays a pivotal role in the toxin sensitivity and activation of BK channels

The accessory ß1 subunits, regulating the pharmacological and biophysical properties of BK channels, always undergo post-translational modifications, especially glycosylation. To date, it remains elusive whether the glycosylation contributes to the regulation of BK channels by ß1 subunits. Methods: Herein, we combined the electrophysiological approach with molecular mutations and biochemical manipulation to investigate the function roles of N-glycosylation in ß1 subunits. Results: The results show that deglycosylation of ß1 subunits through double-site mutations (ß1 N80A/N142A or ß1 N80Q/N142Q) could significantly increase the inhibitory potency of iberiotoxin, a specific BK channel blocker. The deglycosylated channels also have a different sensitivity to martentoxin, another BK channel modulator with some remarkable effects as reported before. On the contrary to enhancing effects of martentoxin on glycosylated BK channels under the presence of cytoplasmic Ca2+, deglycosylated channels were not affected by the toxin. However, the deglycosylated channels were surprisingly inhibited by martentoxin under the absence of cytoplasmic Ca2+, while the glycosylated channels were not inhibited under this same condition. In addition, wild type BK (α+ß1) channels treated with PNGase F also showed the same trend of pharmacological results to the mutants. Similar to this modulation of glycosylation on BK channel pharmacology, the deglycosylated forms of the channels were activated at a faster speed than the glycosylated ones. However, the V1/2 and slope were not changed by the glycosylation. Conclusion: The present study reveals that glycosylation is an indispensable determinant of the modulation of ß1-subunit on BK channel pharmacology and its activation. The loss of glycosylation of ß1 subunits could lead to the dysfunction of BK channel, resulting in a pathological state.(AU)

Inhibitory mechanism of angiotensin-converting enzyme inhibitory peptides from black tea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The aim of this work is to discover the inhibitory mechanism of tea peptides and to analyse the affinities between the peptides and the angiotensin-converting enzyme (ACE) as well as the stability of the complexes using in vitro and in silico methods. Four peptide sequences identified from tea, namely peptides I, II, III, and IV, were used to examine ACE inhibition and kinetics. The half maximal inhibitory concentration (IC