细菌生产人铁蛋白的新功能及应用

铁蛋白(Ferritin)是一种广泛存在于生物体中的笼状蛋白,由24个亚基自组装形成的蛋白质外壳和铁内核两部分组成,是维持机体铁代谢平衡的重要蛋白。最新发现,人血清铁蛋白含量的变化与某些疾病相关,特别是发现利用大肠杆菌重组表达、仿生合成的磁性人铁蛋白具有双功能特性,即识别肿瘤并使其可视化。此外,铁蛋白独特的结构及理化性质使其成为理想的纳米载体,用于构筑多功能肿瘤成像和药物输送的平台。本文重点介绍人铁蛋白的新功能及其在疾病诊断和肿瘤靶向治疗中的应用前景。     

植物铁蛋白转基因的应用

植物铁蛋白是一种铁存放蛋白,既可以储存大量的可被植物利用的铁,又能抵抗环境胁迫。利用铁蛋白的转基因研究不仅可以缓解由于铁缺乏而引起的一系列疾病,而且能提高植物对环境的耐受性,在生物治疗中具有重要意义。文章就铁蛋白的结构以及铁蛋白转基因植物在上述几个领域中的研究进展作简单的介绍。     

抗人铁蛋白单克隆抗体的制备及其在肝癌病人血清铁蛋白测定中的应用

铁蛋白是一种肿瘤相关蛋白质。我们从人肝癌组织中分离纯化了铁蛋白,并筛选到一株抗该铁蛋白的单克隆抗体杂交瘤细胞株（６Ｄ６）,它针对铁蛋白上的构象决定簇,并对人源铁蛋白高度专一。然后我们用此单抗建立了测定铁蛋白浓度的夹心ＥＬＩＳＡ法,并对方法的灵敏度,就确度及特异性作了研究。本法用于测定不同血清标本的结果表明：肝癌病人血清中的铁蛋白浓度明显高于正常人,这可能对临床诊断会有使用价值。     

人心肌酸性铁蛋白的分离纯化及临床应用

人心肌匀浆经热变性,酸化,硫酸铵盐析,超离心、Ｓｅｐｈａｒｏｓｅ ＣＬ－４Ｂ柱层析和制备等电聚焦分离,得到酸性铁蛋白,经鉴定,所得酸性铁蛋白ｐＩ为５．０,Ｈ亚基分子量为２１ｋＤ,Ｌ亚基为１９ＫＤ,ＰＡＧＥ分析呈单一区带,制备了兔抗人酸性铁蛋白抗血清,用该抗血清建立的人酸性铁蛋白放射免疫分析可检测出８０％甲胎蛋白阴性肝癌病人。     

融合铁蛋白表达、纯化及肿瘤摄取分析

铁蛋白由于其靶向性、可逆性自组装、高生物相容性及易被修饰等优点,被认为是一种理想的递送系统。本研究旨在表达纯化3种融合铁蛋白,对其进行鉴定,并探究其肿瘤靶向性。合成3种融合铁蛋白基因并克隆至原核表达载体,使用镍柱进行亲和层析纯化重组蛋白,通过非变性聚丙烯酰胺凝胶电泳(native-PAGE)、Westernblotting、圆二色谱对融合铁蛋白进行鉴定。使用异硫氰酸荧光素酯(fluorescein5-isothiocyanate,FITC)与融合铁蛋白进行反应,利用激光共聚焦扫描显微镜进行体外肿瘤细胞靶向。同时将荧光染料胺活性琥珀酰亚胺酯(sulfo-cyanine7,Cy7-SE)与融合铁蛋白进行反应尾静脉注射入黑色素瘤小鼠进行体内肿瘤成像,探究融合铁蛋白的肿瘤靶向性。结果显示,本研究构建的融合铁蛋白使用异丙基-β-D-硫代半乳糖苷(isopropylthio-β-D-galactoside,IPTG)进行诱导表达可获得约21 kDa的可溶性融合铁蛋白,通过镍柱进行亲和层析纯化获得纯度较高的融合铁蛋白。Westernblotting检测重组蛋白能被相应抗体识别。Native-PAGE、圆二色谱鉴定目的蛋白为具有α螺旋的多聚体。通过体内外肿瘤摄取实验,证明了融合铁蛋白能够被肿瘤细胞和肿瘤组织摄取。本研究成功表达纯化融合铁蛋白并进行鉴定,验证了其在体内外的肿瘤摄取情况,为铁蛋白在生物医药领域的应用奠定了基础。     

铁蛋白分析技术的研究进展

铁蛋白是含铁蛋白质,1943年Cranick用硫酸铵沉淀、超滤、硫酸镉重结晶、凝胶层析等技术,获得铁蛋白,经免疫电泳、等电聚焦电泳和离子交换层析鉴定,血清铁蛋白由含铁单体,     

动物储铁蛋白研究进展

铁元素是生物体中必不可少的微量元素,在生物的生长发育中发挥着重要作用。铁蛋白是一种分布广泛的球形蛋白,能够以稳定的形式储存大量铁。铁蛋白通过储存和释放铁来维持机体内铁平衡。铁蛋白不仅是机体中重要的铁储存蛋白,同时也能有效保护生物体免受来自氧自由基的损伤。与此同时,铁蛋白含量可以作为一些疾病预防检测的明确指标。对铁的代谢吸收及铁对基因调控的研究,进一步说明了维持铁平衡对生物体有重要意义。     

PEG和盐对棕色固氮菌细菌铁蛋白和钼铁蛋白晶体生长的影响

棕色固氮菌（ＯＰ）体内的固氮酶钼铁（ＭｏＦｅ）蛋白和细菌铁蛋白均为重要的生物功能蛋白。前者为生物固氮的关键酶［１］,后者则可为生物代谢贮存丰富而又可溶的铁原子［２］。因而都得到了广泛而深入的研究。Ｋｉｍ［３］报道了ＭｏＦｅ蛋白衍射结果。赵宝光等［２］...     

人心肌酸性铁蛋白的分离纯化及临床应用

人心肌匀浆经热变性、酸化、硫酸铵盐析、超离心、ＳｅｐｈａｒｏｓｅＣＬ－４Ｂ柱层析和制备等电聚焦分离,得到酸性铁蛋白。经鉴定,所得酸性铁蛋白ｐＩ为５．０,Ｈ亚基分子量为２１ｋＤ,Ｌ亚基为１９ｋＤ,ＰＡＧＥ分析呈单一区带。制备了兔抗人酸性铁蛋白抗血清,用该抗血清建立的人酸性铁蛋白放射免疫分析可检测出８０％甲胎蛋白阴性肝癌病人。     

柱孢鱼腥藻的铁蛋白与棕色固氮菌的钼铁蛋白的交叉互补作用

纯化的柱孢鱼腥藻铁蛋白能够与棕色固氮菌的钼铁蛋白有效地交叉反应,展现较高的活性。此异源交叉反应的乙炔还原比活及放氢比活,分别是蓝藻同源互补比活的83.8及66．7％。比较藻铁蛋白与菌钼铁蛋白异源交叉反应及藻固氮酶组分之间的同源反应的动力学特点时发现,铁蛋白对钼铁蛋白的最佳克分子比数前者(异源交叉反应)较后者(藻同源反应)为高,前者为5,后者为1;但反应的时间进程两者差别不大。     

乳腺癌磁共振成像影像表现与糖类抗原153、癌胚抗原、铁蛋白的相关性研究

摘要 目的：探讨乳腺癌患者磁共振成像（MRI）影像表现与糖类抗原153（CA153）、癌胚抗原（CEA）、铁蛋白的相关性。方法：收集2018年1月-2022年3月于中国人民解放军联勤保障部队第九〇一医院经手术病理证实为乳腺癌的患者48例作为研究组,其中临床分期I期15例,II期19例,III期6例,IV期8例。另选取同时期经手术确诊为乳腺良性病变的患者36例作为对照组。分析比较研究组和对照组血清CA153、CEA、铁蛋白含量及不同临床分期乳腺癌患者血清CA153、CEA、铁蛋白含量的差异。采用Pearson分析乳腺癌患者MRI影像学表现与血清CA153、CEA、铁蛋白含量的相关性。结果：研究组血清CA153、CEA、铁蛋白含量均显著高于对照组,差异有统计学意义（P＜0.001）;III-IV期乳腺癌患者血清CA153、CEA、铁蛋白含量均显著高于I-II期,差异有统计学意义（P＜0.001）。经Pearson相关性分析显示,肿瘤直径越大和有淋巴结转移时,血清CA153、CEA、铁蛋白含量越高,即乳腺癌患者肿瘤直径和淋巴结转移与血清CA153、CEA、铁蛋白含量呈正相关性（P＜0.05）;而乳腺癌患者病灶类型、肿瘤形态、肿瘤边缘、强化特征和时间-信号强度曲线与血清CA153、CEA、铁蛋白含量无相关性（P＞0.05）。结论：乳腺癌患者血清CA153、CEA、铁蛋白的含量与临床分期相关,同时与MRI影像检查发现的肿瘤直径和淋巴结转移具有一定相关性。     

磁性氧化铁纳米颗粒及其磁共振成像应用

磁性氧化铁纳米颗粒在磁共振成像方面的应用,已经在全世界范围内得到了广泛的关注,相关研究也被各国科学家高度重视.目前,磁性氧化铁纳米颗粒正在从早期的基于被动识别的肝部磁共振造影,快速转向基于主动识别的磁共振分子影像应用.本文将围绕磁性氧化铁纳米颗粒的生物体内应用,着重介绍磁性纳米颗粒的制备及其在疾病诊断,尤其是在肿瘤早期...     

The trajectories of particles suspended in electrolytes under the influence of crossed electric and magnetic fields

We observed that particles, suspended in an electrolyte and brought into crossed magnetic and electric fields of low intensities, will deviate in the central part of the electrophoresis chamber of a standard Zeiss Cytopherometer with a component vertical to both fields. The direction and magnitude, however, were sharply at variance with what would be expected by the action of the Lorentz force (EMF) on the surface of the particles. The magnitude of the deviation depends upon the magnetic and electric field strength, the ion concentration of the suspension medium and the geometry of the chamber. The movement of the particles is due to streaming of the electrolyte which is mainly caused by inhomogeneities of the electric field in the electrophoresis chamber. The magnitude of the effect is high enough to occur under physiological conditions. Magneto-electrophoretic streaming might eventually act as a transducer mechanism which could explain the ability of some animals to orientate themselves in the geomagnetic field.     

Construction and Characterization of a Goat Mammary Gland cDNA Library

A lactating goat mammary gland cDNA library was constructed by using a modified commercially available cDNA library construction kit protocol. The resulting clones were sequenced and functionally analyzed through cross-species genomic comparison to assess (1) the capacity and functional quality of the constructed library for subsequent research and (2) the efficiency of the procedural modifications. The study resulted in the construction of a high-quality mammary gland cDNA library, which was characterized by (1) the total recombinants number of 1.4 × 10⁷ colony-forming units (cfus) that was at least 10 times greater than the number expected from the application of the standard kit protocol, (2) the recombinants rate of 96%, and (3) the average insert size of 1,082 bp. BLAST analysis of sequenced clones against GenBank databases determined 55.7% of clone redundancy, 22 known function gene clusters, and 29 novel gene clusters. The analysis of the primary gene expression profile showed that 59% of the tested clones were genes that coded for milk proteins while 16% of the clones coded for ribosomal, metabolism, immune response, and translation proteins. The remaining 25% of the tested clones were described as novel genes. Cross-species comparison showed that 77% of characterized gene clusters were successfully identified by using resources from other ruminants and unrelated species. This outcome is in consonance with the common belief that the genomic resources that have been generated across species are potentially powerful tools that could be used for enhancing the molecular understanding of less genomically studied species, such as goat.     

基于磁性纳米微球的Gamma干扰素酶联免疫检测方法建立

目的：建立及评价使用磁性纳米微球作为固相载体的人酌干扰素（Interferon-gamma,IFN-gamma）双抗体夹心酶联免疫吸附实验（Enzyme-linked immunosorbent assay,ELISA）检测方法。方法：以杂化细乳液合成法制备磁性纳米微球,将其作为免疫检测的固相载体。将磁性微球与IFN-酌抗体进行偶联,建立基于磁性微球的ELISA 检测方法,检测人IFN-gamma,绘制IFN-gamma标准曲线并进行方法学评价。结果：获得包被有人IFN-gamma抗体的免疫微球, 抗体偶联率为54.5 %。用它建立IFN-gamma的双抗体夹心的ELISA 检测方法,检测范围为0-1000 pg/mL,相关系数为0.9996,灵敏度23.2 pg/mL,功能灵敏度0 pg/mL,批内和批间变异系数（Coefficients ofVariance,CVs）＜8 %,检测总共需要2 小时。结论：成功制备了IFN-酌免疫微球并建立了定量检测人IFN-gamma的双抗体夹心磁珠酶联免疫方法。     

Serum ferritin: Past,present and future

Background

Serum ferritin was discovered in the 1930s, and was developed as a clinical test in the 1970s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in diagnosing and monitoring these diseases.

Scope of review

In this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool.

Major conclusions

Although many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer.

General significance

Serum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights.