光学蛋白芯片技术在噬菌体M13KO7检测中的应用

将亲和素共价固定在表面改性后的硅片上,通过亲和素与生物素相互作用将生物素标记的噬菌体抗体GP3固定在亲和素膜层表面,当含有M13KO7噬菌体的样品经过抗体表面时,通过噬菌体与抗体之间的相互作用噬菌体就会被抗体捕获,生物学信号可以通过芯片上的膜层厚度变化表现出来,这种膜层厚度变化可以被椭偏生物传感器技术识别。结果表明,GP3抗体在芯片表面形成了饱和的抗体膜层,厚度为6.9nm;M13KO7噬菌体与芯片上固定的抗体会发生特异性相互作用,噬菌体被抗体捕获后形成的复合物膜层厚度为17.5nm,并且随着噬菌体浓度升高膜层厚度增加,检测含有M13KO7噬菌体的样品灵敏度为109pfu/mL。与其它研究病毒与抗体相互作用方法相比光学蛋白芯片技术具有简便快捷、无需标记待检样品和结果直观等优点,为研究病毒与其抗体相互作用以及疾病早期临床诊断提供了一个新的方法。     

膜上相互作用对平板双分子层脂膜电性质的影响

以平板双分子层脂膜作为生物膜的简单模型,建立用平板双分子层脂膜电性质研究药物－生物膜相互作用的方法。研究以具有典型特征的物质－表面活性剂、自由基、金属手性配合物与平板膜的相互作用引起膜电性质的规律性改变;重组人Ｂ型血红细胞膜与溶液中抗Ｂ单克隆抗体发生特异相互作用时,膜电阻快速下降,下降的速率与加入的抗体量成正相关。在研究发生在平板膜上的典型反应的基础上,通过对膜电性质的监测和分析,从而确认平板双分     

基于生物膜干涉技术检测PDL1抗体与PDL1抗原的亲和力

生物膜干涉（biolayer interferometry,BLI）技术可对抗体与抗原的相互作用进行亲和力、动力学的全面分析。在抗体克隆筛选、动力学常数测定中对链霉亲和素（streptavidin,SA）生物传感器的需求量较大,但目前鲜有关于SA传感器重复利用的报道。基于BLI技术、再生SA生物传感器建立一种使用再生后的传感器检测PDL1抗体与PDL1抗原亲和力的方法。通过将生物素化的PDL1抗原偶联至SA生物传感器上,再与单链抗体、双价单链抗体、完整抗体和双特异性抗体这4类PDL1抗体结合,计算抗原抗体的亲和力常数,利用甘氨酸（10 mmol·L^-1,pH 1.7）再生SA传感器,再次进行分子间相互作用力分析。结果显示,重复性相对标准偏差（relative standard deviation,RSD）均值为6.87%,批间重复性RSD为0.82%,稳定性RSD均值为6.13%,说明运用甘氨酸再生后的SA生物传感器测分子间的亲和力数据可靠、重现性好、稳定性高,再生后的传感器可继续用于本样品的实时、无标记的抗原抗体相互作用力分析。BLI技术可节省检测成本,为SA传感器的重复利用提供理论依据。     

纳米多孔硅阻抗生物传感器的研究

构建了1种基于多孔硅材料,无需标记的纳米生物传感器,用于对牛血清白蛋白分子进行检测。通过对多孔硅进行表面处理,形成氧化膜,将抗体固定到多孔硅氧化层表面。在磷酸盐缓冲液中,通过电化学检测系统检测加入抗原后,传感器的阻抗值的变化。磷酸缓冲液（PBS）/抗体-氧化层/硅,构成电解液/绝缘层/半导体（electro-lyte-insulator-semiconductor,EIS）结构。传感器的线性检测范围为0.01～0.27mg/mL,检测限为0.01mg/mL。     

分子识别诱导的蛋白质和核酸多层膜的有序组装

通过生物大分子之间的特异性结合,采用表面等离激元共振技术监测,报导了支撑于固体表面脂单层膜上进行的亲和素、生物素标记的质粒ＤＮＡ、以及从系统性红斑狼疮患者血清中获得的抗ＤＮＡ抗体多层膜的有序组装。这种生物大分子的组装技术可以用于生物传感器以检测特定的抗原抗体。     

分子识别诱导的蛋白质和核酸多层膜的有序组装

通过生物大分子之间的特异性结合,采用表面等离激元共振技术监测,报导了支撑于固体表面脂单层膜上进行的亲和素、生物素标记的质粒ＤＮＡ,以及从系统性红斑狼疮患者血清中获得的抗ＤＮＡ抗体多层膜的有序组装。这种生物大分子的组装技术可以用于生物传感器以检测特定的抗原抗体。     

免疫球蛋白的基因和基因工程

免疫球蛋白具有抗体活性、能与相应的抗原专一地结合,为生物体内普遍存在的最主要的一类抗体蛋白质。免疫球旦白不仅存在于血液中与其它体液中,同时也分布在淋巴细胞膜表面上,所以称前者为分泌型抗体,而称后者为膜结合型抗体。     

一种酶免疫传感器的制备和性能测试

这种酶免疫传感器是采用丝素蛋白溶液将待测抗原(兔IgG)固定在基础电极表面,选用抗体(山羊抗兔IgG-HRP)与其识别结合。利用H2O2将抗原抗体结合的电位响应信号放大而检测抗原的浓度。该传感器测定抗原的最低检测浓度1.0×10-10 mol/L,线性范围1.0×10-8~1.0×10-10 mol/L,响应时间为10s。通过电泳的方法加速抗原抗体的识别结合,反应时间由原来的90min缩短到30min,这在国内外鲜有报道。这种以固定化抗原结合酶标抗体量的多少作为检测抗原标准的新型酶免疫传感器,在临床检测、生物医学研究等领域将会有广阔的应用前景。     

用重组痘苗病毒感染动物细胞表达的Epstein-Barr病毒膜抗原检查IgA/MA抗体

用EB病毒膜抗原基因重组的痘苗病毒感染动物细胞,其细胞表面可表达EB病毒膜抗原,以此膜抗原作为诊断抗原检测血清中IgA/MA抗体,明显优于常用的B95-8细胞表面膜抗原,从而为研究人群血清抗体反应与鼻咽癌的关系,为鼻咽癌的诊断和普查开辟了新的途径。     

检测梅毒螺旋体抗体的纤维膜条方法的建立及其在诊断中的应用

目的：建立以纤维膜为载体的检测梅毒螺旋体抗体的方法,检查病人血清中对梅毒螺旋体多种抗原的抗体,用于梅毒感染的诊断。方法：将基因工程表达及纯化的梅毒螺旋体蛋白tp15、tp17、tp42和tp47分别结合在纤维膜上,用载抗原的纤维膜条检查血清中的抗体,抗体阳性者在相应抗原位置显示出特异条带。结果：梅毒螺旋体感染者血清中存在特异性抗体,在检查的460份临床诊断的患者血清中,对tp15、tp17、tp42和tp47抗原的抗体检出率分别为41.3%、100%、98.7%和51.7%;134份献血员血清抗体阴性。结论：建立的检测梅毒螺旋体感染的方法可同时检查对多种抗原的抗体,以纤维膜条作为诊断条检测血清抗体方法简便,用于临床诊断更特异、更敏感。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.