日本血吸虫26ku谷胱甘肽S－转移酶Sj26抗原肽研究

多肽疫苗;日本血吸虫26ku谷胱甘肽S－转移酶Sj26抗原肽研究     

曼氏血吸虫谷胱甘肽S-转移酶Sm26/2的抗原肽研究

在计算机辅助下,应用Goldkey和PC-Gene程序,根据新报道的曼氏血吸虫谷胱甘肽S-转移酶Sm26/2的氨基酸序列,进行亲水性、柔韧性、可接近性、电荷分布和二级结构分析,预测出6个抗原肽,并用固相法进行了合成.经Dot-ELISA法测定,其中的2个对抗日本血吸虫免疫球蛋白多克隆抗体(抗-Sj-IgG-PcAb)显示出较好的抗原性,1个对抗血吸虫表膜单克隆抗体(A6McAb)显示出较好的抗原性,可作为抗血吸虫病合成多肽疫苗的候选肽段.     

Studies on the Peptides and Polysaccharides in Pollen

The peptides RP3I and PSPP1-4 were purified from the rape and the Papaver Somniferunpollens, respectively. Their sequences and physiological activities were determined and synthesized ex-cept PSPP1. The polysaccharides TAA-C and CPA-E were obtained from Typha Angustifilia andCodonopsis Pilosula pollens, respectively. Their partial characterization and structures were studied.     

Conformational Studies on Potential β-Turn-Forming Model Peptides

The conformational behavior of POE-bound model peptides Boc-(L -Ala)₂-X-Y-(L -Ala)₂-NHPOE (X – Y = L -Pro-Gly ( I ), Gly-L -Ile ( II ); NHPOE = aminopoly(oxyethylene)) as well as of the repetitive hexapeptide of elastin, Boc-L -Val-L -Ala-L -Pro-Gly-L -Val-Gly-A-NHPOE-M ( III ) (A = photosensitive 3-nitro-4-(bromomethyl)benzoyl group; NHPOE-M = aminopoly(oxyethylane) monomethyl ether) has been studied by means of ¹H-NMR and CD spectroscopy. Compounds I and III form a β-turn with Pro and Gly in positions i + 1 and i + 2, respectively, while an aggregated state for II , has been identified. The results are in good agreement with published prediction codes giving experimental evidence for the dominance of short-range interactions to establish secondary structure in solution.     

蛋白质、多肽类药物控制释放体系的研究

近年来,蛋白质、多肽类药物广泛应用于各类疾病的治疗。本文对聚乙二醇修饰的蛋白质及蛋白质类药物控制释放这两大体系的研究进展做了较系统的总结和评述,并就更高级的靶向、易吸收的蛋白质药物体系的发展进行了展望。     

Approaches to Synthetic Vaccines Design of Epitope-Containing Amphiphilic Peptides Matching the Antigenic Structure in the Native Protein

A general procedure for the design of synthetic vaccines with the retained conformational features of protein antigenic determinants is described. This new concept emerges from detailed studies on the relationship between primary sequence and secondary structure formation of synthetic peptides and takes advantage of the amphiphilic nature of epitope-containing peptide segments in the native protein to accomplish structural modifications. These segments, for example amphiphilic helices or β-sheets, are stabilized by the insertion of secondary structure-inducing amino-acid residues on the hydrophobic part of the peptide without affecting the spatial arrangement of functional residues on the hydrophilic side. The availability of amphiphilic peptides with tailor-made conformational properties, e.g. helices, β-sheets, and, moreover, assemblies of these blocks to structures of higher order (‘folding units’), allows the presentation and stabilization of continuous as well as discontinuous epitopes by this approach. This strategy is exemplified for the case of two discontinuous epitopes taken from lysozyme, which are matched to host molecules with adequate conformational features by the help of computer-assisted molecular modelling. The implications of this new concept for the design of synthetic vaccines are discussed with special emphasis to the important role of peptide synthesis and chemical structure modification.     

Functional Molecular Thin Films: Topological Templates for the Chemoselective Ligation of Antigenic Peptides to Self-Assembled Monolayers

The combination of self-assembly and regioselective surface chemistry has made it possible to immobilize peptide recognition sites 1 on a template attached to a gold surface. Each of the seven individual reaction steps, including the final functional biomolecular recognition, was controlled in situ with surface-sensitive detection techniques. The presented strategy is of general importance for the formation of complex supramolecular structures with biologically interesting functionalities at the interfaces.     

刺激响应型肽自组装及其应用

肽自组装体由于具有结构稳定、易调控、生物相容性好、可生物降解等优点,在构筑新型材料及生物医药领域表现出了巨大潜力。本文介绍了肽自组装的概念、机理和应用,详细归纳了刺激响应型肽自组装的研究进展;按照刺激源的不同将刺激响应型肽自组装分为pH响应型肽自组装、温度响应型肽自组装、溶剂响应型肽自组装、光响应型肽自组装、超声波响应型肽自组装以及离子响应型肽自组装;列举了肽自组装在药物控释、脊髓损伤修复、仿酶催化、生物模板等领域的应用。最后,基于目前肽自组装存在的一些问题(如影响肽自组装结构的外界因素不易精准把控、自组装的研究与生命科学领域的交叉程度低等)对肽自组装的发展做了展望。     

人参中氨基酸及多肽的研究

氨基酸及多肽是人参中重要成分之一。田中治,Gstirner等对人参根中氨基酸分析表明,主要有Arg、Lys、Ala、Ser、Tyr、Pro、Gly、Glu、Thr、Leu、Ile、Val、AspPhe、His等,也曾确定含半胱氨酸。我们分析了吉林省集安边条参各部位的氨基酸(见表1)表明,芦头和花蕾各检出16种;根检出15种;侧根、须根和叶各检出14种。     

Comparative Liquid Chromatographic Studies for the Determination of Bioactive Peptides

Reliable and sensitive chromatographic methods have been developed and applied to determine derivatized di- and tripeptides: aspartame, carnosine, glutathione, alanyl-glutamine, and γ-glutamyl-cysteine. Photodiode-array detection was used for dansyl-chloride derivatives, while fluorescent detection was carried out for orthophthaldialdehyde derivatized peptides to obtain higher sensitivity. The sensitivity and detection limits were determined and compared in order to select the most efficient analytical method. Transition metal complexes [zinc(II), cadmium(II), silver(I), and copper(II)] with cysteine containing peptides were also determined with ultraviolet-visible detection. The structural identification was carried out by the analysis of the mass-spectra recorded with an atmospheric pressure chemical ionization method in separate chromatographic experiments.     

功能多肽在肿瘤治疗中的应用及研究进展

多肽具有生物相容性好,功能多样化,生物体内响应性高及合成修饰方法简单易行等优点,已被广泛用于构建靶向药物传递系统。以具有靶向功能和刺激响应性的多肽为基础构建的药物传递系统,能够将药物定向地运送到肿瘤区域。药物传递系统到达肿瘤组织后,在肿瘤组织特殊微环境或外源刺激下,实现药物的精准释放。这种具有特异性肿瘤靶向和刺激响应型的多肽载体可以最大程度地提高药物的抗肿瘤效果,降低药物的毒副作用。本文简要介绍了常用的靶向多肽和刺激响应型多肽,并讨论了基于功能型多肽的药物载体在肿瘤治疗方面的应用。     

Prediction, Synthesis and Antigenicity of the Antigenic Peptides of 26kDa Glutathione S-Transferasc of Schistosoma Japonicum (Sj26)

Schistosomiasisisaworldwideparasiticdiseasethataffectsmorethan200millionpersonsin70countriesallovertheworld.Itisveryimportanttodevelopaneffectivevaccineincludingsignificantlevelsofprotectionagainsttheinvasivestageoftheparasiteforthepreventionofrapidr...     

金属-有机框架材料在活性肽富集中的应用

生物活性肽在整个生理系统当中发挥着重要作用,对于生物活性肽的精确分析将有助于进一步开发其功效,然而当前对复杂生物系统中肽的分析依然存在相当大的难度,这是由于肽通常与高浓度蛋白质共存这一特质所造成的,严重降低了色谱中肽的分离效率,并在质谱中抑制肽的峰信号。鉴于此,人们引入金属-有机框架材料对活性肽进行富集分析。金属-有机框架(MOFs),是由金属离子或团簇和有机配体,通过配位键自行组装形成的具有多孔结构的有机-无机杂化材料。由于它们具有框架结构可调、高孔隙率、化学稳定性良好、可再生性、合成过程简单等优点而广泛应用于活性肽富集、气体吸附与分离、传感器、药物缓释与催化反应等领域。本文系统梳理了近年来MOFs材料用于磷酸肽、糖肽和内源肽等活性肽富集的研究进展,在此基础上总结了当前MOFs材料在该领域中存在的局限,并对研究新趋向提出了展望。     

温控分子动力学研究微管蛋白活性肽链的折叠机制

运用温控和常温分子动力学方法, 研究了微管蛋白活性部位Pep1-28肽链的折叠机制, 总模拟时间为380.0 ns. 对于温控分子动力学, 逐渐降温可以清晰显示Pep1-28肽链的折叠途径, 发生明显折叠的温度约为550 K, 其折叠和去折叠可逆机制为U(>1200 K)←→I1(1200-1000 K)←→I2(800 K)←→I3(600 K)←→I4(450 K)←→F1(400 K)←→F2(300 K), 其中U为去折叠态构象, I1、I2、I3和I4是折叠过程中的四个重要的中间态构象, F1和F2是两个结构相近的折叠态构象. 对于常温(300 K)分子动力学, 其构象转变和折叠过程相当迅速, 很难观察到有效、稳定的中间态构象. 尤其引人注意的是, 其折叠态结构陷入了能量局域极小点, 与温控(300 K)的有较大差异, 两者能量差高达297.53 kJ·mol-1. 可见, 温控分子动力学方法不仅清晰地显示多肽和蛋白质折叠过程的重要中间态构象, 为折叠和去折叠机制提供直接、可靠的依据, 而且还有助于跨越较高的构象能垒, 促使多肽和蛋白质折叠以形成全局能量最低的稳定结构.     

Application of Reductive Samariation to the Synthesis of Small Unnatural Peptides

Considering that the amide NH groups are neither protected nor deprotonated, reductive samariation in the presence of a carbonyl substrate is a remarkably efficient method for the formation of a C-C bond. This was shown for a series of dipeptides and a tripeptide [Eq. (a)]. For the latter the product was obtained in a good yield of 50 %, despite the presence of three amide protons.     

神经网络在ACE抑制肽QSAR中的应用研

通过对天然氨基酸的457种物化性质参数进行主成分分析后得到SVHEHS描述符,用该描述符分别对血管紧张素转化酶(ACE)抑制二肽、三肽、四肽进行表征,并建立了肽结构与活性的神经网络模型。ACE抑制二肽神经网络模型的相关系数、交叉验证相关系数、均方根误差和外部验证相关系数分别为0.946、0.951、0.249、0.852,三肽模型分别为0.973、0.945、0.135、0.813,四肽模型分别为0.915、0.879、0.250、0.814。由此表明SVHEHS描述符结合神经网络对ACE抑制肽的建模效果及模型预测能力均较理想,在此基础上进一步通过平均影响值(Mean impact value,MIV)法确定了显著影响各类肽活性的结构因素,从而为新的强活性ACE抑制肽的分子设计提供了理论基础。     

五氯化磷辅助下氨基酸的自组装成肽反应研究

L-α-氨基酸和D-α-氨基酸可与五氯化磷直接发生磷酰化反应，随后自组装成多肽，但β-氨基酸不能成肽，DL-α-氨基酸成肽困难；在SOCl2存在下，α-氨基酸也不能成肽，用电喷雾质谱研究了氨基酸的自组装反应，反应过程中有五元环状的氨基酸五配位磷中间体生成，使用硅烷基保护的氨基酸，在^31PNMR中可观察到五配位磷中间体。     

The Astexin-1 Lasso Peptides: Biosynthesis,Stability, and Structural Studies

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分子轨道法在四肽电离碎裂过程中的某些应用

本文利用自编LCBO—MO(成键轨道线性组合分子轨道)法计算程序,对二个多肽分子Prop—Phe—Val—Leu—Ala—OMe和Ac—Gly—Gly—Ile—Gly一OMe的主要骨架键断裂几率进行理论计算。并与Kiryushkin等所提供的质谱数据估算的主要肽键骨架键实验断裂几率进行比较,得到较为一致结果。