荧光光谱法研究桑色素与人血清白蛋白的相互作用

采用荧光猝灭光谱、紫外-可见吸收光谱研究了桑色素与人血清白蛋白(HSA)的结合作用。实验表明桑色素对HSA的荧光猝灭属于单一静态猝灭反应,在溶液中以摩尔比1:1牢固结合,各结合反应的平衡常数Kp>105,结合常数Kb>104;根据F rster非辐射能量转移机理,求算HSA与桑色素间距离r为3.81~3.58nm,能量转移效率E为0.18~0.13。并根据结合反应的热力学常数推测了药物与HSA之间的主要作用力类型为疏水作用力和偶极-偶极作用力。     

人血清蛋白- 葡聚糖偶合抗原的制备与表征

将葡聚糖用NaIO4 氧化成带醛基的产物,再与人血清蛋白(HSA)中的氨基反应形成不稳定的席夫碱,在还原剂硼氰氢化钠(NaCNBH3)的作用下,成为稳定的拟糖蛋白抗原,并对影响偶合反应的几个方面进行讨论,包括：不同分子质量的葡聚糖、葡聚糖氧化所用NaIO4 的量、氧化葡聚糖与HSA 的比例和偶合时间。结果表明：偶合反应的最佳条件为：葡聚糖T40 与氧化剂NaIO4 物质的量比为1:187,偶合溶液pH9.0,氧化葡聚糖T40 与HSA物质的量比为4:1,偶合时间 12h。质量相等的不同类型葡聚糖,葡聚糖分子质量越大,氧化时需要的氧化剂越多,氧化度越高接枝度也越高。     

羟基肉桂酸衍生物的合成及其与人血清白蛋白的相互作用

以咖啡酸、间羟基肉桂酸为母体,分别与止血芳酸反应,设计合成两种羟基肉桂酸衍生物(E)-4-{[1'-(3″,4″-二羟基苯基)丙烯酰氨基]甲基}苯甲酸(Ⅰ)、(E)-4-{[1'-(3″-羟基苯基)丙烯酰氨基]甲基}苯甲酸(Ⅱ),并用MS、IR、1HNMR、13CNMR进行结构表征。采用荧光光谱法、同步荧光光谱法、紫外可见光谱法结合分子对接技术研究其在体外生理条件下与人血清白蛋白(HSA)之间的相互作用机制。光谱实验结果表明,衍生物Ⅰ和Ⅱ都可以使HSA的内源荧光发生静态猝灭,相互作用力主要是氢键和范德华力,且对HSA的构象产生一定影响。分子对接结果表明,衍生物Ⅰ、Ⅱ与HSA结合在亚结构域ⅡA(即site I)中,作用力主要是氢键和范德华力,同时还存在着疏水作用,且衍生物距色氨酸残基(Trp214)很近,很好地解释了衍生物有效猝灭HSA内源荧光的实验现象。分子对接与实验获得了一致性的结果,二者相互佐证,提高了实验结果推断的准确度。     

野黄芩苷及其苷元与人血清白蛋白的相互作用

采用荧光光谱研究了野黄芩苷及印黄芩素与人血清白蛋白(HSA)的相互作用,确定了野黄芩苷及印黄岑素对HSA荧光猝灭过程的猝灭机理为静态猝灭。测定了不同pH条件下野黄芩苷及印黄岑素与HSA的结合常数、结合位点数。     

Investigation of an albumin‐enriched fraction of human serum and its albuminome

The removal of albumin and other high abundance proteins is a routine first step in the analysis of serum and plasma proteomes. However, as albumin can bind proteins and peptides, there is a universal concern as to how the serum proteome is changed by the removal of albumin. To address this concern, the current study was designed to identify proteins and peptides removed from the serum during albumin depletion; to determine which of these are bound to albumin (rather than copurified) and whether the bound proteins are intact proteins or peptide fragments. Sequential, independent analyses including both anti‐albumin antibody (anti‐HSA) affinity chromatography and SEC were used to isolate albumin‐bound proteins. RP‐HPLC and 1‐D SDS‐PAGE were then used to further separate the proteins prior to identification by MS/MS. Finally, whole protein molecular weight (MW) MS measurements coupled with protein coverage obtained by MS were combined to assess whether the bound proteins were intact or peptide fragments. Combining the results from multiple approaches, 35 proteins, of which 24 are intact, were found to be associated with albumin, and they include both known high and low abundance proteins.     

基于SVM和GA的药物与人血清白蛋白结合的预测

为降低新药在临床实验的失败率,提高新药的ADME特性,在制药初期需考虑预测药物与HSA（人血清白蛋白）的结合能力,以提高预测正确率为目标并因此选取合适的制药成分。首先采用遗传算法对分子描述符进行筛选,然后利用支持向量机（SVM）模型预测药物与HSA的结合能力。针对支持向量机的分类精度和泛化能力取决于核函数参数选取的特点,提出了基于粒子群优化算法（PSO）的SVM核参数优化选择法。通过PSO自动获取SVM最佳核参数,并将结果同双线性网格搜索法比较,结果表明,建立的模型对药物与HSA之间的结合能力有较高的预测性,正确率达到86%。     

基于和声搜索算法的PMU分布式测量的研究

本文提出了一种基于PMU测量数据并用于估算配电网负载模型的和声搜索(Harmony Search)改进分布式测量。由于近年来分布式发电的发展,燃料电池和风力涡轮机等的接入使得配电网的拓扑结构进一步复杂。因此,需要通过改变传统的分布荷载模型来克服这个问题。估算模型不仅要在网络正常条件下和真实模型作出相同的反应,而且在网络故障和瞬态条件下是有效的。在本文中,负荷模型及其相应的方程已被修改。双反馈感应电机(DFIM)的参数估算以及在网络频率变化情况下负载电源的可靠性都包含在模型中。该模型在Matlab/Simulink环境下进行仿真验证该算法的有效性。     

Dialdehyde Starch Nanocrystals as a Novel Cross-Linker for Biomaterials Able to Interact with Human Serum Proteins

In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5–15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.     

Integrated approach of network reconfiguration with distributed generation and shunt capacitors placement for power loss minimization in radial distribution networks

This article presents the significance of efficient hybrid heuristic search algorithm(HS-PABC) based on Harmony search algorithm (HSA) and particle artificial bee colony algorithm (PABC) in the context of performance enhancement of distribution network through simultaneous network reconfiguration along with optimal allocation and sizing of distributed generators and shunt capacitors. The premature and slow convergence over multi model fitness landscape is the main limitation in standard HSA. In the proposed hybrid algorithm the harmony memory vector of HSA is intelligently enhanced through PABC algorithm during the optimization process to reach the optimal solution within the search space. In hybrid approach, the exploration ability of HSA and the exploitation ability of PABC algorithm are integrated to blend the potency of both algorithms. The box plot and Wilcoxon rank sum tests are used to show the quality of the solution obtained by hybrid HS-PABC with respect to HSA.The computational results prove the integrated approach of the network reconfiguration problem along with optimal placement and sizing of DG units and shunt capacitors as an efficient approach with respect to power loss reduction and voltage profile enhancement. The results obtained on 69 and 118 node network by hybrid HS-PABC method and the standard HSA reveals the effeciency of the proposed approach which guarantees to achieve global optimal solution with less iteration.