Permeation through Phospholipid Bilayers,Skin‐Cell Penetration,Plasma Stability,and CD Spectra of α‐ and β‐Oligoproline Derivatives

After a survey of the special role, which the amino acid proline plays in the chemistry of life, the cell‐penetrating properties of polycationic proline‐containing peptides are discussed, and the widely unknown discovery by the Giralt group (J. Am. Chem. Soc. 2002 , 124, 8876) is acknowledged, according to which fluorescein‐labeled tetradecaproline is slowly taken up by rat kidney cells (NRK‐49F). Here, we describe details of our previously mentioned (Chem. Biodiversity 2004 , 1, 1111) observation that a hexa‐β³‐Pro derivative penetrates fibroblast cells, and we present the results of an extensive investigation of oligo‐L ‐ and oligo‐D ‐α‐prolines, as well as of oligo‐β²h‐ and oligo‐β³h‐prolines without and with fluorescence labels ( 1 – 8 ; Fig. 1). Permeation through protein‐free phospholipid bilayers is detected with the nanoFAST biochip technology (Figs. 2–4). This methodology is applied for the first time for quantitative determination of translocation rates of cell‐penetrating peptides (CPPs) across lipid bilayers. Cell penetration is observed with mouse (3T3) and human foreskin fibroblasts (HFF; Figs. 5 and 6–8, resp.). The stabilities of oligoprolines in heparin‐stabilized human plasma increase with decreasing chain lengths (Figs. 9–11). Time‐ and solvent‐dependent CD spectra of most of the oligoprolines (Figs. 13 and 14) show changes that may be interpreted as arising from aggregation, and broadening of the NMR signals with time confirms this assumption.     

.液相芯片技术在检验医学和生物医学中的应用

 液相芯片技术是以100种不同荧光编码的微球作为探针的载体,生物分子间的反应在悬浮液态体系中进行的一类新的生物芯片技术.在这个灵活和开放的平台中可进行蛋白质、核酸等生物大分子的检测.液相芯片较传统的固相芯片的优势在于检测准确、信息质量稳定、可重复性好.液相芯片以其易于操作、高通量、高灵敏度、高准确度、高精密度以及宽的线性测定范围的特点,逐渐进入了临床诊断领域.     

miRNAs芯片数据的聚类分析与羽扇豆醇抗癌途径预测

羽扇豆醇是一种植物天然提取物,具有高效低毒的抗癌活性,对于药物开发领域有很高价值。目前对其抗癌机制还不是十分明确。使用TaqMan MicroRNA Assay芯片技术,从羽扇豆醇处理的hela细胞中miRNA的差异表达入手,探索扇豆醇抗癌分子途径。运用聚类分析等统计学方法和targetscan,RNAfold等序列分析工具进行信号组分的预测筛选,再结合对NC-BI,Gene Ontology等大型生物信息数据库的检索,最终在生物信息学层面上,分析得到hela细胞中羽扇豆醇抗癌的分子调控途径,即以受体酪氨酸激酶ERBB4介导的,hsa-miR-23b,hsa-miR-200b等几种miRNA参与的分子通路。     

Mechanistic study of membrane concentration and recovery of Listeria monocytogenes

Detection of the foodborne pathogen Listeria monocytogenes requires that food samples be processed to remove proteins and lipids, concentrate microorganisms to a detectable concentration, and recover the concentrated cells in a small volume compatible with micron-scale biochips. Mechanistic considerations addressed in this research include the roles of membrane structure, pore size, and detergents in maximizing recovery of cells from a complex biological fluid. The fluid in this case was a food sample (hotdog extract) inoculated with L. monocytogenes. This study showed how membrane filtration using a syringe filter is able to concentrate L. monocytogenes by 95x with up to 95% recovery of living microorganisms by concentrating 50 mL of food sample into a volume of 500 microL. Tween 20 was added to the sample to prevent irreversible adsorption of the microorganism to the membrane and thereby help to ensure high recovery. Comparison of polycarbonate, mixed cellulose, nylon, and PVDF membranes with 0.2 to 0.45 microm pores showed the 0.2 microm polycarbonate membrane with straight through, mono-radial pores gives the highest recovery of living microorganisms. The mixed cellulose, nylon, and PVDF membranes have a fibrous structure whose characteristic openings are much larger than their effective pore size cut-offs of 0.22 or 0.45 microm. We define conditions for rapid membrane-based cell concentration and recovery that has the potential to supplant enrichment steps that require a day or more. This approach has the added benefit of facilitating examination of a large amount of fluid volume by reducing its volume to a range that is compatible with the microliter scales of biochip or other biosensor detection systems.     

质粒DNA抗原芯片检测抗双链DNA抗体的初步研究

目的:建立以质粒DNA作为抗原的检测血清中抗双链DNA(dsDNA)抗体的芯片方法,并与酶联免疫吸附实验比较,初步探讨用芯片法检测抗dsDNA抗体的临床价值。方法:将原核表达载体质粒pcDNAⅡ用质粒DNA快速抽提试剂盒提取纯化DNA后按1∶2稀释,用点样仪点在经3-氨丙基三乙氧基硅烷(APES)修饰的玻片上,温孵后用含有1%小牛血清白蛋白和2.5%蔗糖的PBST封闭,以Cy3标记的人IgG为二抗,建立检测dsDNA抗体的芯片方法,并与德国欧蒙公司生产的抗双链DNA检测ELISA试剂盒做比较,对包括58例系统性红斑狼疮(SLE)、25例干燥综合征(SS)、10例皮肌炎(DM)和7例类风湿关节炎(RA)在内的病人和60例健康人对照进行了抗dsDNA的对比检测。结果:对阳性标本的检测,与现用常规检测方法ELISA相比,芯片检测抗dsDNA的灵敏度为91.3%,特异度为90.7%,阳性预测值为89.3%,阴性预测值为92.5%;对健康对照的检测,2种方法均为阴性,符合率为100%。结论:与ELISA相比,用质粒DNA作为抗原建立的芯片方法的灵敏度和特异度较高,为今后建立同时检测多个自身抗体的芯片奠定了基础。     

肿瘤表观基因组学、生物芯片和生物信息学

肿瘤的分子生物学研究一直是生命科学和医学研究的热点,随着科学技术的发展,高通量的分析方法在分子生物学研究中的广泛应用,使其成为肿瘤研究的一种高效手段,同时表观基因组学和生物信息学也促进了肿瘤学的发展,本文就表观基因组学、生物芯片和生物信息学方法在肿瘤研究中的应用进行综述,并对未来的发展和展望进行了讨论。     

生物芯片技术研究进展

生物芯片主要包括基因芯片、蛋白质芯片、组织芯片等。利用生物芯片技术可以从整个基因组的水平上对基因进行快速分析、筛选。本文主要概述了生物芯片技术的最新研究进展及在各个领域内的应用 ,并对生物芯片技术面临的挑战以及未来的发展方向作了讨论。     

植物功能基因组研究进展

随着植物基因组计划的深入,植物基因组学研究的重点已经转变为基因组功能的研究,即利用基因组序列的信息和高通量的系统分析技术,在基因组水平研究植物结构和组织与植物功能在细胞、有机体和进化上的关系.对功能基因组学研究的内容、方法以及最新研究进展进行了综述.