protein

摘要： Inhibition of protein misfolding and aggregation is a great challenge in the field of biochemical and biopharmaceutical engineering.Alzheimer’s disease(AD)is a protein-misfolding disease,and the interactions between 40-amino-acid-residueβ-amyloid peptide(Aβ_(40)) and its N-terminal truncated peptide Aβ_(11-40) demonstrate that Aβ_(11-40) may play an important role in the pathological process of AD.However,the effect of inhibitors on Aβ_(11-40) aggregation and on the cross-amyloid aggregation(coassembly)between Aβ_(40) and Aβ_(11-40) has never been studied.Herein,coaggregation and seeding interactions between Aβ_(40) and Aβ_(11-40) as well as the effect of epigallocatechin gallate(EGCG),a small molecule inhibitor,on the cross-amyloid aggregation have been investigated by extensive analyses.It is found that Aβ_(11-40) participates in the aggregation of Aβ_(40) and leads to the formation of coaggregates that contain lessβ-sheet structures than pure Aβ_(40) aggregates.The aggregation kinetics along with morphologies and secondary structures of the coaggregates are also significantly affected by the Aβ_(40)/Aβ_(11-40) ratio.EGCG accelerates the nucleation of Aβ_(40) but retards that of Aβ_(11-40) by affecting their elongation and secondary nucleation processes in solution and on solid surfaces.Meanwhile,EGCG makes the conformations of the seeding-induced Aβaggregates more compact,especially for the homologous seedings.Isothermal titration calorimetry measurement indicates that hydrophobic interactions mainly contribute to the inhibition of the two Aβisoforms by EGCG.The findings of this research have provided new insights into Aβaggregation and the effect of an important inhibitor and the results would benefit in the development of potent inhibitors against co-assembly of different amyloid proteins.

摘要： Enzymatic hydrolysis has been widely used to produce bioactive hydrolysates from sea cucumber body wall.Here,inspired by the clarification of Apostichopus japonicus genome,we investigated the enzymatic hydrolysis of sea cucumber body wall by using the omics strategy.Shared proteins,including major yolk proteins,collagens,extracellular matrix glycoproteins and muscle proteins,were released from the body wall by different hydrolysis condition.A portfolio of 216 shared peptides were detected in the peptidome by papain with different hydrolysis time,while 32 shared peptides were detected in the peptidome by differing proteases.Unshared peptides and the relative abundance distribution profiles of shared peptides changed depending on hydrolysis approaches,indicating dynamic changes of peptidome during hydrolysis.Moreover,release of sulfated fucan and fucosylated chondroitin sulfate changed with the hydrolysis condition.The monitoring of dynamic enzymatic hydrolysis process at a molecular scale would contribute to production and quality control of sea cucumber hydrolysates.

摘要： Background: Japanese women’s body mass index (BMI) was known to be the lowest among people in OECD countries. We wanted to compare foods intakes and relationships between intakes of particular food species and BMI. Methods: We asked young and middle-aged women to participate and used a brief-type self-administered diet history questionnaire (BDHQ) to know the amounts of various food species they took. Results: Weights and BMI of young and middle-aged women were not different. Middle-aged women took almost all species of foods and energy more than young women. Except for cholesterol of soluble dietary fibers, there was no correlation between foods intakes and BMI. Conclusion: Both young and middle-aged Japanese women are lean (BMI;around 22). Middle-aged women took more energy, and proteins, carbohydrates, and lipids compared with young women. Middle-aged women spend more energy on house workings than young women in Japan.

摘要： Objective:To explore the anticoagulant,antiplatelet and antioxidant activities of protein extract of kenaf seed(PEKS).Methods:Sodium dodecyl sulphate polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography techniques were employed for protein characterization.Antioxidant activity of PEKS was assessed using 1,1-diphenyl-2-picrylhydrazyl(DPPH)assay.The protective effect of PEKS on sodium nitrite(NaNO2)induced oxidative stress was evaluated using the in vitro red blood cell model,while the effect of PEKS on diclofenacinduced oxidative stress was examined in vivo in rats.Platelet-rich plasma and platelet-poor plasma were used for anticoagulant and antiplatelet activities of PEKS.Results:PEKS revealed similar protein bands on SDS-PAGE under reduced and non-reduced conditions.Several acidic proteins were present in native PAGE.PEKS showed antioxidant properties by scavenging DPPH with an IC50 of 24.58μg.PEKS exhibited a protective effect on NaNO2 induced oxidative stress in red blood cells by restoring the activity of stress markers.In addition,PEKS alleviated diclofenac-induced tissue damage of the liver,kidney,and small intestine.PEKS showed an anticoagulant effect in both in vivo and in vitro experiments by enhancing normal clotting time.PEKS did not affect prothrombin time but increase activated partial thromboplastin time.Furthermore,PEKS inhibited adenosine diphosphate and epinephrine-induced platelet aggregation.Conclusions:PEKS protects tissues from oxidative stress and exhibits antithrombotic activity.

摘要： Background:The majority of attenuated total reflection Fourier transform infrared(ATR FT-IR)investigations of cotton are focused on the fiber tissue for biological mechanisms and understanding of fiber development and maturity,but rarely on other cotton biomass comp on ents.This work examined in detail the ATR FT-IR spectral features of various cott on tissues/organs at reproductive and maturation stages,an a lyzed and discussed their biological implications.Results:The ATR FT-IR spectra of these tissues/organs were an a lyzed and compared with the focus on the lower wavenumber fingerprinting range.Six outstanding FT-IR bands at 1730,1620,1525,1235,1050 and 895 cm^(-1) represented the major C=O stretching,protein Amide I,Amide II,the O-H/N-H deformation,the total C-O-C stretching and the β-glycosidic linkage in celluloses,respectively,and impacted differently between these organs with the two growth stages.Furthermore,the band intensity at 1620,1525,1235,and 1050 cm^(-1) were exclusively and significantly correlated to the levels of protein(Amide I bond),protein(Amide II bond),cellulose,and hemicellulose,respectively,whereas the band at 1730 cm^(-1) was negatively correlated with ash content.Conclusions:The resulting observations indicated the capability of ATR FT-IR spectroscopy for monitoring changes,transportation,and accumulation of the major chemical components in these tissues over the cotton growth period.In other words,this spectral technology could be an effective tool for physiological,biochemical,and morphological research related to cotton biology and development.

摘要： Despite numerous reported lithium metal batteries(LMBs) with excellent cycling performance achieved in labs, transferring the high performing LMBs from lab-scale to industrial-production remains challenging. Therefore, via imitating the stand-still process in battery production, a conventional but important procedure, to investigate the formation and evolution of a solid electrolyte interface(SEI) is particularly important for LMBs. Our previous studies indicate that zein(corn protein)-modified carbonate-ester electrolyte(the most commercialized) effectively improves the performance of LMBs through guiding Li-ions and repairing cracked SEI. Herein, we investigate the formation and evolution of the protein-modified SEIs on Li anodes by imitating the stand-still temperature and duration. A simulation study on the protein denaturation in the electrolyte under different temperatures demonstrates a highly unfolded configuration at elevated temperatures. The experiments show that this heat-treated-zein(H-zein) modified SEI forms quickly and becomes stable after a stand-still process of less than 100 min. Moreover, the Hzein SEI exhibits excellent wetting behavior with the electrolyte due to the highly unfolded protein structures with more functional groups exposed. The Li|Li cell with the H-zein SEI achieves prolonged cycling performance(>360 h vs. ~260 h of the cell with the untreated-zein(U-zein) modified SEI). The Li Fe PO_(4)|Li cell with the H-zein SEI shows much stable long-term cycling performance of capacity retention(70% vs.42% of the cell with U-zein SEI) after 200 cycles. This study confirms that the appropriately treated protein is able to effectively improve the performance of LMBs, and will inspire future studies for the production process of LMBs toward their commercialization.

摘要： Due to the boost of CO_(2)/NO_(x)emissions which cause environmental pollution,processes that remove such pollutants from flue gas have attracted increasing attention in recent years.Among these technologies,biological CO_(2)/NO_(x)emission reduction has received more interest.Microalgae,a kind of photosynthetic microorganism,offer great promise to convert CO_(2)/NO_(x)to biomass with high content of lipid and protein,which can be used as feedstock for various products such as biodiesel,health products,feedstuff and biomaterials.In this paper,biological CO_(2)/NO_(x)removing technologies by microalgae,together with the products(such as biofuel and protein)and their economic viability are discussed.Although commercial applications of microalgae for biodiesel and protein products are hampered by the high production cost of biomass,the use of CO_(2)/NO_(x)from flue gas as carbon and nitrogen sources can reduce the cost of biomass production,which makes these technologies more competent for real-life applications.Moreover,it is projected that the increasing in CO_(2)allowances will lead to further reduction in the cost of biomass production,which especially favors related products with lower values such as biodiesel.Furthermore,by combining various process optimization and integration,biorefinery is proposed and considered as the crucial component for the sustainable and economically feasible bulk applications of microalgae biomass.

摘要： Comparison between different biological sequences is a key step in bioinformatics when analyzing similarities of sequences and phylogenetic relationships. A method of graphically representing biological sequences known as Chaos Game Representation (CGR) has achieved many applications in the studies of bioinformatics. The key issue in the application of CGR is to extract as many useful features as possible from CGR. Initially, CGR was applied to DNA sequences, but in this paper, a CGR-based approach is used to extract suitable features for comparing protein sequences of SARS-CoV-2 and other viruses. For this aim, several viral protein sequences from 12 groups are considered and CGR centroid, amino acid frequency, compounded frequency, Shannon entropy, and Kullback-Lieber Discrimination Information are applied to find the inter-relationship among the sequences. The experimental results demonstrate the potential strengths of CGR-based method for examining the evolutionary relationship of protein sequences. Our method is powerful for extracting effective features from protein sequences, and therefore important in classifying proteins and inferring the phylogeny of viruses.

摘要： A well understanding about protein adsorption into charged polymer brushes is of importance in the elucidation of mechanism and important phenomena(such as “chain delivery”effect) in protein adsorption on polymer-grafted ion exchange adsorbents. In this work, quartz crystal microbalance with dissipation(QCM-D) was introduced to in situ investigate lysozyme adsorption on QCM sensors grafted with poly(3-sulfopropyl methacrylate)(pSPM) via atom transfer radical polymerization. It was achieved by analyzing frequency(f) and energy dissipation(D) shift simultaneously on pSPM-grafted sensors. The result showed that an initial decrease in ΔD was typical of lysozyme adsorption on pSPM-grafted sensor and more significant with an increase of chain length and grafting density. It was attributed to significant water release in the hydration layer of protein and polymer chains in lysozyme adsorption into pSPM brushes.On pSPM-grafted sensors with long and dense chains, furthermore, lysozyme transitioned from monolayer to multilayer adsorption and the maximum adsorbed amount was obtained to be 374.0 ng·cmamong all pSPM-grafted sensors in this work. The results in D-f plot further revealed that lysozyme adsorption into pSPM brushes increased the rigidity of adsorbed layer and little structure adjustment of adsorbed lysozyme. It was unfavorable for “chain delivery” effect for facilitated transport of adsorbed protein. This work provided valuable insight into protein adsorption in pSPM brushes and outlined a feasible approach to increasing mass transport in polymer-grafted ion exchange adsorbents.

摘要： [Objectives]To explore the differences in nitrogen accumulation and transport characteristics and grain protein content of wheat varieties with different nitrogen efficiencies and their responses to irrigation.[Methods]Under field conditions,using nitrogen-inefficient varieties Luohan 17 and Xinhua 818 and nitrogen-efficient varieties Bainong 418 and Bainong 419 as materials,this paper studied the nitrogen accumulation and transport characteristics,grain protein content and protein yield of wheat with different nitrogen efficiencies under rainfed and irrigated conditions.[Results]Compared with the nitrogen-inefficient wheat varieties,the pre-flowering nitrogen transport and the shoot nitrogen accumulation at the mature stage of nitrogen-efficient wheat varieties decreased by 15.08%and 28.25%,respectively,and the grain protein content decreased by 11.66%,under rainfed conditions.Compared with rainfed conditions,nitrogen accumulation in shoots of nitrogen-inefficient wheat varieties and nitrogen-efficient wheat varieties at the mature stage increased by 6.59%and 67.05%,respectively,and grain protein content decreased by 13.50%and 3.47%,respectively,under irrigated conditions.The two nitrogen efficiency types of wheat had different responses to irrigation after flowering.After irrigation,the nitrogen accumulation of nitrogen-efficient varieties increased by 274.80%,while that of nitrogen-inefficient varieties decreased by 51.15%.Finally,the grain protein yield of nitrogen-inefficient wheat varieties remained stable,while the grain protein yield of nitrogen-efficient wheat varieties increased by 40.37%.[Conclusions]The nitrogen accumulation and transport characteristics and grain protein content of wheat varieties with different nitrogen efficiencies are different under different irrigation conditions.In production,it is necessary to take different irrigation measures in accordance with the difference in nitrogen efficiency of wheat varieties,so as to increase the protein content of wheat grains.

摘要： 本发明公开了一种重组ProteinA蛋白及亲和层析介质的制备方法，所述的蛋白为SEQ ID No 1、SEQ ID No 2所定义的亲本免疫球蛋白‑结合蛋白的突变体；所述亲和层析介质的制备方法包括以下步骤：S1、合成重组ProteinA蛋白的基因，S2、利用所述S1中合成的基因分别构建表达载体，S3、培养并表达纯化得到序列对应的SEQ ID的重组Protein A溶液，S4、利用所述重组Protein A制备得到亲和层析介质。有益效果：本发明通过对氨基酸序列重新设计，大大提高Protein A在碱液中的化学稳定性，从而提供一种对抗体具有特异性结合作用的Protein A，其在碱性条件下具有良好的化学稳定性，重组Protein A亲和层析介质结合载量显著提高，可耐受0.5‑1.0M NaOH在位清洗，IgG结合载量60‑90mg/ml。

摘要： 本发明涉及一种PMMA基质的Protein A亲和层析介质及其制备方法和应用。包括如下步骤：对聚甲基丙烯酸甲酯微球进行亲水化处理，制备亲水性聚甲基丙烯酸甲酯微球；将该亲水性聚甲基丙烯酸甲酯微球、碱和环氧化合物混合，反应，制备环氧化聚甲基丙烯酸甲酯微球；将环氧化聚甲基丙烯酸甲酯微球、Protein A、乙二胺四乙酸、巯基甘油、助剂混合，反应，制备PMMA基质的Protein A亲和层析介质，其具有亲水性好，耐碱性强，耐酸性强，粒径较小，粒径均一，机械强度高的优点，分离效果好，可在高流速下使用，可提高生产效率，成本低廉，适合用于生物大分子的快速分离纯化、连续流层析，具有广阔的应用前景。

摘要： 本发明提供一种可用于Protein A亲和层析连续流工艺开发的研究方法，属于生物制药技术领域，包括以下步骤：批次亲和层析工艺参数开发阶段、单柱亲和层析工艺穿透曲线确认阶段、双柱亲和层析工艺上样载量确认阶段、3柱位或者4柱位连续流层析确认阶段I和3柱位或者4柱位连续流层析确认阶段II；本发明通过较为简洁快速的试验流程，为亲和层析等其他层析连续流工艺开发提供一定的指导作用，缩短该部分工艺开发的时间，加速连续流层析在蛋白纯化技术方面的应用范围。

摘要： 本发明公开了一种重组Protein A蛋白，该重组Protein A蛋白是由Protein A蛋白的E结构域、D结构域、A结构域及B结构域或Z结构域的一个或多个突变体构成，此外该重组Protein A蛋白也可以由4‑8个重复的突变体组合的重复单元构成，本发明另一方面公开了一种包含重组Protein A蛋白突变体或突变体组合的重复单元的亲和层析介质及其制备方法和应用。基于本发明提供的重组ProteinA蛋白，具有较好的化学稳定性、耐碱性以及更为优异的IgG结合能力，因此本发明提供的重组Protein A蛋白作为亲和配基制备亲和层析填料，应用于抗体的分离纯化。

摘要： 本发明属于生物工程领域，公开了一种Protein L‑HRP及其制备方法和应用。采用基因工程方法制备的Protein L‑HRP具有高纯度和良好的生物活性，可用于检测Fab、diabody或者scFv。

摘要： 本发明公开了一种Protein G磁珠快速检测新冠病毒IgG抗体的方法和检测装置，基于Protein G磁珠ELISA的对血清样本中Anti‑RBD IgG的显色检测，包括：S1.新冠病毒重组蛋白RBD‑MSH与生物素化多肽GK‑Biotin偶联，得到生物素化新冠病毒重组蛋白RBD‑MS‑Bio，新冠病毒重组蛋白RBD‑MSH的氨基酸序列如SEQ ID No.2所示；S2.血清液样本与Protein G磁珠孵育，得到磁珠吸附样本，加入生物素化新冠病毒重组蛋白RBD‑MS‑Bio进行孵育，再加入酶标链霉亲和素HRP‑Strep孵育，得待检体系，待检体系中加入TMB显色液，得到显色结果。本发明大大缩短了检测时间，避免检测人群因采样大规模聚集而造成感染的问题，保证对新冠病毒抗体检测的准确性和稳定性。

摘要： 本发明公开了灰飞虱致死基因片段Ribosomal protein L19及其应用。本发明筛选出经干扰后能够导致灰飞虱死亡的序列如SEQ ID NO.1所示的灰飞虱致死基因片段Ribosomal protein L19，利用该基因片段的dsRNA饲喂灰飞虱、褐飞虱，可有效地致死灰飞虱、褐飞虱，本发明对环境生态和食品都安全，为建立利用RNA干扰技术控制害虫提供了新途径。

摘要： 本发明提供了一种新型复合多糖protein A磁珠及其制备方法，同时采用琼脂糖及一种或多种其他具有亲水性可交联的间隔臂(纤维素、葡聚糖)进行成球，可以将纤维素或者葡聚糖覆盖在以琼脂糖微球的表面，琼脂糖在微球中充当骨架作用，纤维素或葡聚糖可以一端固定在琼脂糖骨架上，游离的另一端与蛋白A进行结合，从而达到增加微球的比表面积，增加微球载量，进而降低纯化成本的目的。

摘要： 本发明公开了一种提升谷氨酰胺转氨酶产量的方法，通过增强VOC family protein基因SMDS_2194的转录水平，进而提高谷氨酰胺转氨酶产量的方法。通过在茂原链霉菌C2中，利用人工强启动子kasOp*过量表达内源VOC family protein基因SMDS_2194，得到高产谷氨酰胺转氨酶的突变株TGS102。增强VOC family protein基因SMDS_2194的转录水平可明显提高谷氨酰胺转氨酶产量。本发明所得的工程菌株TGS102的谷氨酰胺转氨酶发酵终产量在实验室摇瓶水平下较对照菌株提高105.48％。

摘要： 本发明涉及免疫检测技术领域，公开了一种检测非洲猪瘟病毒抗体的ELISA检测试剂盒。本发明应用protein L酶结合物和包被有非洲猪瘟病毒衣壳蛋白P72三聚体的酶标板，两者联合制备检测非洲猪瘟病毒抗体的ELISA检测试剂盒，所述试剂盒能够快速而特异地检测血清中非洲猪瘟病毒抗体，且反应灵敏性极高，其操作简便、成本低廉、反应结果稳定，适于在大规模养殖中对猪群进行非洲猪瘟的监测、排查工作，易于大范围推广应用。