水稻金属硫蛋白ricMT的一级结构特征分析

为了获得水稻金属硫蛋白 ric MT的一级结构特征 ,通过等电点和蛋白稳定性预测 ,初步判断 ric MT蛋白是一个不稳定的酸性蛋白 ;并用 ric MT氨基酸序列对 EMBL 蛋白数据库进行检索 ,得到 5 0余个同源性较高的来自动植物的 MT蛋白 ,用二重序列对排分析和氨基酸组成模式分析与已知的蛋白进行比较 ,将 ric MT归属于植物类金属硫蛋白类型。采用多重序列比较法总结出植物类金属硫蛋白的一级结构的三点特征 :相对分子量比动物 MT大 ,平均为 71个氨基酸残基 ;与哺乳动物 MT不同的独特氨基酸组成模式 ;一级结构典型的三段式分布 ,间隔区多数达 3 0～ 40个氨基酸残基     

利用菲律宾花蛤的金属硫蛋白作为镉污染的检测指标

以菲律宾花蛤Ruditapes philippin Adams et Reave为实验动物,分别提取其外套膜和内脏团等组织的金属硫蛋白,经Sephadex G-75葡聚糖柱层析纯化后,用DV-600紫外可见分光光度计测定每个样品金属硫蛋白的吸收值,以研究菲律宾花蛤体内的金属硫蛋白浓度与镉污染之间的关系.结果表明:诱导实验能使检测菲律宾花蛤的内脏团和外套膜的金属硫蛋白含量均明显增加;金属硫蛋白的吸收值与菲律宾花蛤重量、壳长、壳宽均有较大的相关性.从这些关系中,认为利用金属硫蛋白作为菲律宾花蛤镉污染的检测指标是可行的.     

花生 2S 蛋白的提取分离及部分性质研究

用低盐缓冲液提取加热处理的方法分离了花生种子的２Ｓ蛋白组分,用激光质谱法测定了２Ｓ蛋白各组分的分子量;用高效液相色谱法测定了２Ｓ蛋白的氨基酸组成;用差示扫描量热法测定了２Ｓ蛋白的加工工艺性质．研究结果表明花生２Ｓ蛋白主要由１７种多肽组成,富含Ｃｙｓ及Ｍｅｔ等含硫氨基酸,且具有很强的耐热性与亲水性．     

人胎肝金属硫蛋白的分离纯化及酶联免疫吸附检测

人胎肝经匀浆、离心、乙醇沉淀后,通过Sephadex G-75、DEAE-Sepharose Fast Flow柱层析分离,获得金属硫蛋白的两种亚型(MT-1和MT-2)。经氨基酸组成分析证明是均一的。MT-1为抗原免疫青紫兰兔制备了抗血清,以纯化的IgG建立了人MT的酶联免疫吸附检测(ELISA)方法,并给出了标准工作曲线。     

钝顶螺旋藻中藻蓝蛋白的分离纯化及特性研究

为发展新型海洋药物,采用ＳｅｐｈａｃｒｙｌＳ－２００凝胶层析和羟基磷灰石柱层析对人工养殖钝顶螺旋藻中的藻蓝蛋白进行了分离和纯化,得到了藻蓝蛋白纯品。测定了藻蓝蛋白的氨基酸组成和含量。藻蓝蛋白的紫外、可见吸收光谱表明其最大特征吸收波长为２７８,３６０,６２０ｎｍ。得到的藻蓝蛋白经等电聚焦显示为一条带,其等电点为ｐＨ＝４．３。还测量了藻蓝蛋白红外吸收光谱。研究所获得的藻蓝蛋白为后续开展临床应用提供了可靠的样品。     

金属硫蛋白的研究进展

 金属硫蛋白是一类广泛存在于生物体内的多功能诱导性蛋白.作者对近年来在金属硫蛋白的结构、分类、功能及测定方法等方面研究取得的进展做了简要的介绍,同时提出了一些金属硫蛋白研究中存在的问题,并对金属硫蛋白将来可能的应用前景进行了展望.     

鸭肝金属硫蛋白的分离纯化及鉴定

以信阳华英鸭为材料,用ZnSO4诱导其肝脏合成金属硫蛋白(MT),将鸭肝材料经Sephadex G-50柱层析和DEAE-Sepharose CL-6B阴离子交换柱层析2次分离纯化,得到Zn-MT,该MT由61个氨基酸组成,其中半胱氨酸含量约为28%,分子量6.5 KD.鸭肝Zn-MT产率为0.57 mg/kg鲜肝重,在220 nm有吸收峰.     

抗铜酿酒酵母铜结合蛋白的纯化及性质研究

酿酒酵母Ｃｕ＾２＋抗株ＹＮＤ２１经含一定浓度的氯化铜培养基诱导培养后,收集菌体,破碎细胞,离心后ＳｅｐｈａｄｅｘＧ－５０和ＤＥＡＥ－ｃｅｌｌｕｌｏｓｅ柱层析分离可获得三种铜结合蛋白ＤＥ－１,ＤＥ－２,ＤＥ－３。ＤＥ－１脱盐后（Ｇ－１）经鉴定具有金属硫蛋白的特性：表观分子量约为１８ｋＤ;每分子蛋白含２０个巯基,结合１１个铜原子;氨基酸组成中富含半胱氨酸（１８％）、碱性和酸性氨基酸,而酪氨酸和蛋氨酸含     

金属硫蛋白研究进展

介绍了金属硫蛋白的结构、理化性质和主要功能，金属硫蛋白转录与表达，并对国内外金属硫蛋白与锌、铅、镉、钙的代谢研究，金属硫蛋白与辐射关系，肿瘤的发生、治疗及预后的一些进展进行了介绍，说明了金属硫蛋白有着广阔的应用前景。     

花生2S蛋白提取分离及部分性质研究

用低盐缓冲液提取加热处理的方法分离了花生种子２Ｓ蛋白组分，用激光质谱法测定了２Ｓ蛋白各组分的分子量；用高效液相色谱法测定了２Ｓ蛋白的氨基酸组成；用差示扫描量热法测定了２Ｓ蛋白的加工工艺性质。     

Metallothionein gene cluster is split by chromosome 16 rearrangements in myelomonocytic leukaemia

The metallothioneins (MTs) are a family of proteins of low relative molecular mass which bind heavy-metal ions. MTs exist in several molecular forms (MT-I, MT-II) and are encoded by a multi-gene family containing at least 14 closely related genes and pseudogenes. These proteins function in the regulation of trace-metal metabolism, the storage of these ions in the liver, and as a protective mechanism against heavy-metal toxicity. Somatic cell hybridization has shown that most MT genes, including the functional MT genes (MT1A, MT1B, MT2A), lie on human chromosome 16. Using in situ hybridization, we have now localized the MT genes to band q22 of chromosome 16. This chromosomal band is also a breakpoint in two specific rearrangements, the inv(16)(p13q22) and t(16; 16)(p13;q22) rearrangements, found in a subgroup of patients with acute myelomonocytic leukaemia (AMML). Hybridization of a MT probe to malignant cells from two patients with an inv(16) showed labelled sites on both arms of the inverted chromosome, indicating that the breakpoint at 16q22 splits the MT gene cluster. Similar results were obtained when this probe was hybridized to metaphase cells from two patients with a t(16; 16). These results suggest that the MT genes or their regulatory regions may function as an 'activating' sequence for an as yet unidentified cellular gene located at 16p13.     

高纯度黄芩素的制备及表征

提出了由黄芩制备高纯度黄芩素的方法。采用酸沉碱溶法从黄芩中提取黄芩苷,通过水解黄芩苷制取黄芩素粗品,再经硅胶和聚酰胺柱层析纯化,得高纯黄芩素,用高效液相色谱法（HPLC）测得其纯度为99.35%。采用正交试验法优化了实验条件,并对最佳条件下制备的黄芩素纯品进行了红外吸收光谱（FTIR）、紫外吸收光谱（UV）和核磁共振氢谱（¹H-NMR）表征,结果表明其为目标产物。      

Force production by disassembling microtubules

Microtubules (MTs) are important components of the eukaryotic cytoskeleton: they contribute to cell shape and movement, as well as to the motions of organelles including mitotic chromosomes. MTs bind motor enzymes that drive many such movements, but MT dynamics can also contribute to organelle motility. Each MT polymer is a store of chemical energy that can be used to do mechanical work, but how this energy is converted to motility remains unknown. Here we show, by conjugating glass microbeads to tubulin polymers through strong inert linkages, such as biotin-avidin, that depolymerizing MTs exert a brief tug on the beads, as measured with laser tweezers. Analysis of these interactions with a molecular-mechanical model of MT structure and force production shows that a single depolymerizing MT can generate about ten times the force that is developed by a motor enzyme; thus, this mechanism might be the primary driving force for chromosome motion. Because even the simple coupler used here slows MT disassembly, physiological couplers may modulate MT dynamics in vivo.     

基于混合能量收集的移动边缘计算系统资源分配策略

针对移动终端(mobile terminal,MT)从环境射频源收集能量较少的问题,研究基于混合能量收集的移动边缘计算系统资源分配策略.通过在基站覆盖区域内部署多个磁感应能量快速充电站,当MT从环境射频源收集的能量即将耗尽时,在附近的磁感应能量快速充电站补充能量.MT通过移动边缘计算将计算任务分流到边缘服务器.将资源分...     

从东北红豆杉树叶中提取紫杉醇的过程分析

通过实验,分析和讨论了东北红豆杉树叶中紫杉醇的提取过程,采用无毒、无污染的乙醇作为提取溶剂,在高分子树脂柱和Ｚｏｒｂａｘ－ＳＷ柱上进行了逐级提纯,得到了较高纯度的产品,测定了洗脱过程中紫杉烷类化合物的浓度分布情况,为进行规模化生产提供了合理的工艺路线     

Cdc42 and mDia3 regulate microtubule attachment to kinetochores

During mitosis, the mitotic spindle, a bipolar structure composed of microtubules (MTs) and associated motor proteins, segregates sister chromatids to daughter cells. Initially some MTs emanating from one centrosome attach to the kinetochore at the centromere of one of the duplicated chromosomes. This attachment allows rapid poleward movement of the bound chromosome. Subsequent attachment of the sister kinetochore to MTs growing from the other centrosome results in the bi-orientation of the chromosome, in which interactions between kinetochores and the plus ends of MTs are formed and stabilized. These processes ensure alignment of chromosomes during metaphase and their correct segregation during anaphase. Although many proteins constituting the kinetochore have been identified and extensively studied, the signalling responsible for MT capture and stabilization is unclear. Small GTPases of the Rho family regulate cell morphogenesis by organizing the actin cytoskeleton and regulating MT alignment and stabilization. We now show that one member of this family, Cdc42, and its effector, mDia3, regulate MT attachment to kinetochores.     

LEO卫星通信系统位置管理的多星选择策略

针对低轨卫星移动通信系统用户在多星覆盖的情况下的位置注册问题，提出了仰角和覆盖时间加权策略。这种策略既可保证注册卫星覆盖移动终端的时间长，又可保证移动终端处于低仰角的概率低，保证较好的寻呼信道条件，减少了位置更新和寻呼移动终端的信令开销。     

兔抗小鼠IgG-HRP酶标抗体的制备及应用

制备并纯化小鼠腹水IgG,鉴定IgG纯度;免疫新西兰大白兔制备兔抗小鼠IgG的抗血清并纯化血清IgG;用改良过碘酸钠法制备兔抗小鼠IgG酶标抗体,对其进行鉴定,并与市场上的同类产品对比。结果,纯化的小鼠腹水IgG,其纯度约为80%—90%;免疫新西兰大白兔所制备的抗血清免疫双扩散效价在1：32以上;用改良过碘酸钠法制备酶标兔抗小鼠IgG酶标结合物与市场同类产品相比质量优良,特异性较强,亲和力较好,并在较长时间内效价稳定。结果表明,制备的小鼠IgG抗血清和酶标抗体,适合于小鼠的血清学检测体系的建立。