地衣芽孢杆菌β—甘露聚糖酶的纯化及其性质的研究

地衣芽孢杆菌１Ｂａｃｉｕｕｓ Ｌｉｃｈｅｎｉｆｏｒｍｉｓ）ＢＬ－３０６产生的胞外β－甘露聚糖酶经硫酸铵分级盐析,ＤＥＡＥ－纤维素柱层析。Ｓｅｐｈａｄｅｘ－Ｇ１００柱凝胶过滤和ＤＥＡＥ－纤维素柱再层析分离纯化,得到ＳＤＳ－聚丙烯酰胺凝胶电泳（ＳＤＳ－ＰＡＧＥ）均一样品。用ＳＤＳ－ＰＡＧＥ测得纯化后β－甘露聚糖酶分子量为２６０００道尔顿。用凝胶等电聚焦电泳（ＰＡＧＥＩＥＦ）测得等电点ＰＩ为５．０。该酶     

地衣芽孢杆菌β—甘露聚糖酶的纯化及酶学性质

地衣芽孢杆菌（Ｂａｃｉｌｌｕｓ ｌｉｃｈｅｎｉｆｏｒｍｉｓ）ＮＫ－２７菌株发酵产生的β－甘露聚糖酶（β－ｍａｎｎａｎａｓｅ）经硫酸铵盐析沉淀,两次ＤＥＡＥ纤维素和Ｓｅｐｈａｄｅｘ Ｇ－１００离子交换柱层析以及制备ＰＡＧＥ等步骤,获得了凝胶电泳均一的样品。用ＳＤＳ－凝胶电泳测得纯化后的β－甘露聚糖酶分子量为２６ｋＤ,用凝胶聚焦电泳测得等电点Ｐ１为５．０。酶反应的最适ｐＨ为９．０,最适温度为６０℃,稳     

人胃腺苷脱氨酶的分离纯化及性质研究

用硫酸铵分级沉淀、ＤＥＡＥ－纤维素离子交换层析、免疫亲和层析、ＳｅｐｈａｄｅｘＧ－１００凝胶柱层析从人胃组织中提取出腺苷脱氨酶。酶纯化１９３２４倍,比活力为５７９７Ｕ／ｍｇ蛋白。提取酶液经ＰＡＧＥ、ＳＤＳ－ＰＡＧＥ和等电聚焦只呈现一条区带。测得该酶的分子量为４１．２ｋＤ,等电点为ｐＨ４．８,氨基酸组成分析表明该酶由３８８个氨基酸残基组成,Ｎ端氨基酸为精氨酸。酶的最适ｐＨ为６．５,ｐＨ小于５．０或大     

南方鲇碱性磷酸酶的分离纯化及部分性质的研究

用正丁醇抽提,硫酸铵分级沉淀,ＤＥＡＥ－纤维素和Ｓｅｐｈａｃｒｙｌ Ｓ－２００柱层析,从南方鲇（Ｓｉｌｕｒｕｓ ｍｅｒｉｄｉｏｎａｌｉｓ Ｃｈｅｎ）肠粘膜中提取出碱性磷酸酶（ＡＫＰ）。提纯倍数为３９．５０倍,比活为６８．３５μ／ｍｇ蛋白,提取酶液经ＰＡＧＥ和ＳＤＳ－ＰＡＧＥ只呈现一条区带。该酶的分子量为１３２ １４０,Ｎ末端氨基酸为门冬氨酸,最适ｐＨ为１０．１０,７．５＞ｐＨ＞１１．５时不稳定,最     

菜豆幼苗EPSP合成酶的分离纯化和它的部分性质

利用硫酸铵分级沉淀,Ｓｅｐｈｅｄｅｘ Ｇ－５０凝胶柱层析,ＦＰＬＣ Ｍｏｎｏ－Ｑ和磷酸纤维素离子层析法从菜豆幼苗中分离提纯了ＥＰＳＰ合成酶。该酶被纯化２９６１．６倍,比活性达到６２１９．４ｎｍｏｌｍｇ＾－１蛋白ｍｉｎ＾－１。该酶分子量经ＳＤＳ－ＰＡＧＥ检测为５１ｋＤ,等电点为ｐＨ５．７,酶促反应最适ｐＨ７．５,最适温度４５℃。６．２μｍｏｌ／Ｌ的除草剂草甘膦能抑制ＥＰＳＰ合成酶活性的５０％。     

人血红细胞酷氨酸蛋白磷酸酶（PTPP）的研究：Ⅱ.胞浆PTPP的分离纯…

人血红细胞胞浆部分经（ＮＨ４）２ＳＯ４沉淀,ＤＥＡＥ－纤维素（ＤＥ２）柱层析,磷酸纤维素柱层析（Ｐ１１）得到部分纯化的ＰＴＰＰ,产率;５．７％,提纯１０７５倍。以＾３２Ｐ－Ｔｙｒ－Ｐｏｌｙ（Ｇ４：Ｔ）作底物,测得其表征Ｋｍ约为０．５－０．８μｍｏｌ／Ｌ。该酶的最适ｐＨ和最适温度分别为７．０－７．８及３７－４０℃。Ｚｎ＾２＋等二价金属离子及Ｎａ３ＶＯ４等酸根基团对其活性有明显的抑制作用;ＥＤＴＡ、甘     

诺卡氏菌形放线菌β-甘露聚糖酶的纯化和性质

产β－１,４－Ｄ甘露聚糖酶的诺卡氏菌形放线菌（Ｎｏｃａｒｄｉｏｆｏｒｍ ａｃｔｉｎｏｍｙｃｅｔｅｓ）菌株ＮＡ３－５４０,发酵培养７２ｈ,发酵液离心去菌体,上清经硫酸铵沉淀,９５％乙醇沉淀,ＣＭ－Ｓｅｐｈａｄｅｘ Ａ５０柱层析、羟基磷灰石柱层析、ＤＥＡＥ－纤维素离子交换及Ｓｅｐｈａｄｅｘ Ｇ－１００分子凝胶过滤柱等步骤,β－甘露聚糖酶的比活提高了１３７倍,获得凝胶电泳均一的蛋白样品。经ＳＤＳ－ＰＡＧ     

人胃腺苷脱氨酶的分离纯化及性质研究

用硫酸铵分级沉淀、ＤＥＡＥ－纤维素离子交换层析、免疫亲和层析、ＳｅｐｈａｄｅｘＧ１００凝胶柱层析从人胃组织中提取出腺苷脱氨酶,酶纯化１９３２４倍,比活力为５７９７Ｕ／ｍｇ蛋白．提取酶液经ＰＡＧＥ、ＳＤＳ－ＰＡＧＥ和等电聚焦只呈现一条区带。测得该酶的分子量为４１．２ｋＤ,等电点为ｐＨ４．８．氨基酸组成分析表明该酶由３８８个氨基酸残基组成,Ｎ端氨基酸为精氨酸。酶的最适ｐＨ为６．５,ｐＨ小于５．０或大于９．０时不稳定;最适温度为３７℃,对热不太稳定,以腺苷及２－脱氧腺苷作为底物,其Ｋｍ分别为８７μｍｏｌ／Ｌ和４１μｍｏｌ／Ｌ。     

夏威环毛蚓纤溶酶的分离纯化及部分性质研究

以夏威环毛蚓（Ｐｈｅｒｅｔｉｍａ ｈａｗａｙａｎａ）为材料,采用磷酸盐缓冲液抽提、（ＮＨ４）２ＳＯ４分段盐析,离子交换树脂 Ｄ２９０、 Ｓｅｐｈａｄｅｘ Ｇ－１００和 ＤＥＡＥ－ｓｅｐｈａｄｅｘ Ａ－５０三种连续柱层析方法得到一种在 ＰＡＧＥ上显示单一区带的纤溶酶组份。采用凝胶柱层析和 ＳＤＳ－ＰＡＧＥ测其分子量为 １２ ０００和 １２３００,由一条肽链组成。该酶具有强烈的纤溶活力和水解ＢＡＥＥ的活力,能直接作用纤维蛋白和间接激活纤溶酶原。其最适反应温度为４５℃,最适反应ｐＨ为８．０。该酶水解ＢＡＥＥ的活力可被Ｎａ＋、Ｋ＋、Ｍｇ２＋、Ｈｇ２＋、金属离子和ＥＤＴＡ、巯基乙醇抑制,Ｃａ＋则有激活作用。该酶中性糖含量为５％,氨基酸组成中Ａｒｇ、Ｌｅｎ含量较多．     

蛇毒蛋白C激活物的初步研究

目的：研究蝮蛇毒蛋白Ｃ激活物的分离纯化与理化性质。方法：经ＤＥ５２－纤维素、ＣＭ－Ｓｐｈａｄｅｘ Ｃ－５０、Ｇ－７５柱层析,从安徽芜湖产蝮蛇（Ａｇｋｉｓｔｒｏｄｏｎ ｈａｌｙｓ）蛇毒中纯化一种均一的蛋白Ｃ激活物（ＰＣＡ）。结果：ＳＤＳ－ＰＡＧＥ测定分子量约为１５５０００Ｄａ,ＩＥＦ－ＰＡＧＥ测定等电点为４．８。它能使人血浆的ＫＰＴＴ明显延长,显示出强烈的抗凝活性。通过中和试验与显色肽定量实验表明,     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Similar aerosol emission rates and viral loads in upper respiratory tracts for COVID-19 patients with Delta and Omicron variant infection

Highlights
1 Aerosol emission rates of Delta or Omicron patients were similar.
2 Viral loads in upper respiratory tract of Alpha, Delta and Omicron patients were similar.
3 Viral loads in upper respiratory tract of vaccinated or unvaccinated Delta patients had no difference.     

Recombinant human interferon-α1b inhibits SARS-CoV-2 better than interferon-α2b in vitro

Highlights
1) A comprehensive evaluation method for anti-SARS-CoV-2 drugs was established based on RT-qPCR, TCID₅₀ method, and immunofluorescence.
2) A significant antiviral effect of rHuIFN-α1b was shown with EC₅₀=0.12 IU/mL in Vero cells and EC₅₀=0.52 IU/mL in Calu-3 cells, which was better than rHuIFN-α2b (EC₅₀=0.25 IU/mL in Vero cells and EC₅₀=2.48 IU/mL in Calu-3 cells).
3) rHuIFN-α1b has a good potential in the application of anti-COVID-19 therapy.     

Continued antigenic variation of highly pathogenic avian influenza A (H7N9) virus in laying hens in China, 2020–2021

Highlights
1. 13 strains of H7N9 viruses from laying hens in 2020 and 2021 were identified.
2. H7N9 viruses in China comprised at least 11 genotypes.
3. H7N9 viruses are high pathogenic in chickens, not in ducks.
4. The most H7N9 viruses cross-reacted poorly with H7-Re3 antiserum.
5. The H7-Re3 vaccine was unable to prevent H7N9 infection.