条斑紫菜R-藻红蛋白提纯工艺研究

对条斑紫菜叶状体R-藻红蛋白提纯方法进行了研究和分析。首先分别采用冻融法、化学试剂法、溶胀法等单一及组合细胞破碎方法对条斑紫菜细胞进行破碎,结果表明溶胀 组织捣碎法效果最佳。其次用25%～60%饱和度范围内的硫酸铵沉淀法粗提藻红蛋白,发现25%～45%硫酸铵分步沉淀法效果最好,再经结晶法盐析纯度(D565nm/D280nm)达到2.088。盐析液用SephadexG-25层析柱脱盐,再经羟基磷灰石(HA)柱层析,纯度可达到4.98。R-藻红蛋白的最大吸收峰在565nm,其室温荧光发射峰为578nm。SDS-PAGE结果显示,R-藻红蛋白可分为α、β两个亚基,Mr分别为17.0×103和19.0×103。     

紫球藻藻红蛋白的分离纯化及光谱学特性

采用4℃反复浸提、离心、硫酸铵沉淀、DEAE—Sepharose Fast Flow离子交换柱层析,从紫球藻（Porphyridium cruentum Naegeli）冻干粉中分离纯化藻红蛋白,分离纯度达到4．85,总收率51．9％;经羟基磷灰石柱层析纯化,藻红蛋白纯度达到5．10,总收率34．0％,聚丙烯酰胺凝胶电泳显示1条带。所分离纯化的藻红蛋白含有3个亚基（α、β、γ）,在可见光区545nm和560nm处有2个吸收峰,在498nm处有1个吸收肩峰。实验结果说明所分离纯化的藻红蛋白纯度符合要求。     

用膨化柱填料的方法从红藻中规模分离纯化R-藻红蛋白

以Phenyl-sepharose作为柱填料,用streamline柱层析技术从红藻(Palmaria palmata (Lannaeus) Kuntze)中规模分离捕光色素蛋白--R-藻红蛋白.由于不是传统的从层析柱上方进样,而是用泵将样品从streamline层析柱的下方加样(从下至上),因而解决了用一般层析柱分离R-藻红蛋白时海藻抽提液中大量的粘性多糖堵塞层析柱的难题.用P.palmata粗提液上样后,分别用0.2 mol/L、 0.1 mol/L和0.05 mol/L的(NH4)2SO4溶液从相反的方向(即从上到下)洗脱层析柱,发现这些洗脱液中的藻红蛋白纯度已经较高.然后将洗脱液透析去盐,用阴离子交换柱层析(Q-sepharose)进一步纯化.经过这两次柱层析后,R-藻红蛋白的纯度(OD565/OD280)超过3.5,高于一般认可的R-藻红蛋白的纯度标准3.2;产率为每克冷冻P.palmata可纯化0.122 mg高纯度的R-藻红蛋白,比使用一般分离方法的产率要高10倍.这些结果表明,使用本文报道的方法纯化藻红蛋白,将会使作为生化检测试剂的藻红蛋白市场价格大幅度下降.     

用膨化柱填料的方法从红藻中规模分离纯化R—藻红蛋白

以Phenyl-sepharose作为柱填料,用streamline柱层析技术从红藻（Palmaria palmata(Lannaeus)Kuntze）中规模分离捕光色素蛋白-R-藻红蛋白。由于不是传统的从层析柱上方进样,而是用泵将样品从streamline层析柱的下方加样（从下至上）,因而解决了用一般层析柱分离R-藻红蛋白时海藻抽提液中大量的粘性多糖堵塞层析柱的难题。用P.palmata粗提液上样后,分别用0.2mol/L、0.1mol/L和0.05mol/L的（NH4）2SO4溶液从相反的方向（即从上到下）洗脱层析柱,发现这些洗脱液中的藻红蛋白纯度已经较高。然后将洗脱液透析去盐,用阴离子交换柱层析（Q-sepharose）进一步纯化。经过这两次柱层析后,R-藻红蛋白的纯度（OD565/OD280）超过3.5,高于一般认可的R-藻红蛋白的纯度标准3.2;产率为每克冷冻P.palmata可纯化0.122mg高纯度的R-藻红蛋白,比使用一般分离方法的产率要高10倍,这些结果表明,使用本报道的方法纯化藻红蛋白,将会使作为生化检测试剂的藻红蛋白市场价格大幅度下降。     

条斑紫菜藻胆蛋白提纯方法优化探索

采用溶胀法与组织捣碎法相结合的紫菜叶状体细胞破碎方法.研究了不同物液比、缓冲液浸泡时间和硫酸氨盐析次数对藻胆蛋白纯度和产率的影响,对比了各种羟基磷灰石的层析效果,并对所得藻红蛋白和藻蓝蛋白做了吸收光谱、荧光发射光谱和SDS-PAGE鉴定.结果表明,在物液比为1:5,浸泡时间为36h时,紫菜综合破碎效果最佳;经过4次硫酸氨盐析后,藻红蛋白和藻蓝蛋白的纯度最高,分别达到1.71和0.98,采用Siegelman的方法制备的羟基磷灰石一次层析所得藻红蛋白和藻蓝蛋白的纯度最高,分别达到4.73和4.42,产率分别为0.144%和0.042%,且光谱和电泳鉴定结果均达到商品化要求.     

藻胆蛋白质的提取纯化与生物活性研究进展

藻胆蛋白的提取原料主要来自于红藻和蓝藻;细胞破碎的方法主要有反复冻融法、化学试剂处理法等5种方法;提取的方法主要有盐析法等3种;分离纯化的方法主要有层析法等3种;藻胆蛋白其生物活性主要表现在:抗肿瘤活性、抗病毒活性、抗氧化和消炎活性,提高免疫活性。     

硫酸铵三步盐析对藻胆蛋白纯化的影响

主要研究了多次硫酸铵盐析对条斑紫菜藻胆蛋白提取纯化效果。对分离提取的对条斑紫菜藻胆蛋白溶液进行了3次硫酸氨溶液盐析,实验结果表明:55%饱和度可以将绝大部分藻胆蛋白盐析;采用不同组合(15%、20%、25%、30%、35%、40%、45%7个饱和度分别与50%、55%、60%3个饱和度两两组合)二步硫酸铵盐析沉淀藻胆蛋白,使R-藻红蛋白和C-藻蓝蛋白的盐析后纯度(A564/A280)分别达到了1.0和0.45以上,得率分别为1.4%和0.95%;第3次硫酸铵盐析使R-藻红蛋白、C-藻蓝蛋白的纯度分别达到了1.4和0.4以上,最终产率分别为1.3%和0.8%,而变藻蓝蛋白产率有所下降(从0.65%到0.49%),但纯度变化不大。实验证明了采用多次盐析方法可以很大程度提高藻胆蛋白纯度。     

藻红蛋白的高效异源生物合成及其生物活性

[目的]实现藻红蛋白在大肠杆菌中的高效生物合成。[方法]将藻红蛋白生物合成的多个基因构建到单一表达质粒上,质粒转化大肠杆菌后获得表达菌株,优化诱导物、诱导温度和诱导时长等发酵条件,利用亲和层析法分离纯化重组藻红蛋白,分析重组蛋白的光谱学性质与抗氧化活性。[结果]获得了高效生物合成藻红蛋白的大肠杆菌菌株,以乳糖为诱导物时最佳诱导条件为:2.0 g/L的乳糖、25℃下诱导28 h,藻红蛋白表达量达211.6 mg/L;以IPTG为诱导物时最佳诱导条件为:0.4 mmol/L的IPTG,在25℃条件下诱导28 h,藻红蛋白表达量达188.7 mg/L。藻红蛋白色基结合率达92.0%,OD555/OD280为8.0。[结论]成功实现了藻红蛋白在大肠杆菌中的高效生物合成,重组藻红蛋白具有羟基自由基的清除活性。     

坛紫菜藻红蛋白的规模化制备

为了优化坛紫菜粗提工艺以减轻纯化的压力,研究了我国主要经济红藻之一坛紫菜藻红蛋白大规模制备方法。实验采用“溶胀+组织捣碎”法破碎坛紫菜叶状体细胞,对比了多次硫酸铵梯度盐析对破碎液中藻红蛋白的影响,并进一步用羟基磷灰石层析制备藻红蛋白,最后对所得蛋白做了光谱和电泳鉴定。结果表明,经过4次盐析,藻红蛋白吸收光谱纯度达到0.9 (A564/A280),每次的最佳盐析浓度分别为15％、50％、10％和40％;7 kg阴干紫菜经过4次盐析和1次羟基磷灰石层析后可获得507.82 mg藻红蛋白 (A564/A280＞     

用膨化柱填料的方法从红藻中规模分离纯化R-藻红蛋白(英)

以Phenyl_sepharose作为柱填料 ,用streamline柱层析技术从红藻 (Palmariapalmata (Lannaeus)Kuntze)中规模分离捕光色素蛋白———R_藻红蛋白。由于不是传统的从层析柱上方进样 ,而是用泵将样品从streamline层析柱的下方加样 (从下至上 ) ,因而解决了用一般层析柱分离R_藻红蛋白时海藻抽提液中大量的粘性多糖堵塞层析柱的难题。用P .palmata粗提液上样后 ,分别用 0 .2mol/L、0 .1mol/L和 0 .0 5mol/L的 (NH4) 2 SO4溶液从相反的方向 (即从上到下 )洗脱层析柱 ,发现这些洗脱液中的藻红蛋白纯度已经较高。然后将洗脱液透析去盐 ,用阴离子交换柱层析 (Q_sepharose)进一步纯化。经过这两次柱层析后 ,R_藻红蛋白的纯度 (OD565/OD2 80 )超过 3.5 ,高于一般认可的R_藻红蛋白的纯度标准 3.2 ;产率为每克冷冻P .palmata可纯化 0 .12 2mg高纯度的R_藻红蛋白 ,比使用一般分离方法的产率要高 10倍。这些结果表明 ,使用本文报道的方法纯化藻红蛋白 ,将会使作为生化检测试剂的藻红蛋白市场价格大幅度下降。     

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.     

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     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

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.     

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).     

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.