烷基酚聚氧乙烯醚的MALDI-TOF-MS研究

烷基酚聚氧乙烯醚是一类使用极为广泛的非离子型表面活性剂，其分子结构为含重复单元数目不同的系列化合物组成的合成高分子化合物，质谱方法能准确地对其进行分子端基、重复单元、分子量分布等结构表征。     

酚醛树脂的质谱分析研究

质谱能快速而准确地给出被测样品分子量的绝对值。普通质谱不能用于高分子聚合物分析的主要原因是高分子的不挥发性利不稳定性，采用软离子化技术可在一定技术程度上克服上述困难。     

树枝状化合物的MALDI-TOF质谱表征

树枝状化合物(Dendrimers)又称"串连分子"(Cascade molecules),是一类纳米尺寸级别的合成高分子.自20世纪90年代以来,由于它广泛的以及潜在的用途,受到了大量的关注,有关它的合成方法、物理及化学性质的研究在不断增多,一个重要的极具挑战的领域是对它的准确鉴定.     

HPLC分离MALDI-TOF-MS鉴定合成多肽的研究

A method for the separation and characterization of synthetic peptide was established using high performance liquid chromatography ans matrix assisted laser desorption ionization time of flight mass spectrometry. The influences of several factors on its performance were carefully investigated. The method has been successfully used for the analyses of one hundred synthetic peptide samples.     

抗肿瘤药物顺铂和血清白蛋白的相互作用研究

Cisplatin is a widely used anticancer agent to treat solid tumours such as ovarian, testicular cancers. The interaction of platinum drugs with human albumin is an important issue that contributes to understanding the transport process of platinum drugs, cell uptake and their side-effects. Here, we applied a bottom-up proteomic approach to study the interaction of cisplatin with recombinant human albumin(rHA). The cisplatin-rHA complexes were prepared under physiological conditions in vitro at different cisplatin/rHA molar ratios for different incubation times. LC/MS analysis enables to identify four platinated peptides and further MS/MS analysis characterizes the platinum binding sites. The results show that cisplatin binds to His67, His128, His247 and Met298 residues in albumin involving an intramolecular crosslinking of His67 to His247 by platinum. Besides, cisplatin is shown to induce the cleavage of the disulfide bond Cys124-Cys169 of albumin and bind to the thiol in the reduced Cys124 residue.     

新型内切肝素酶酶解产物肝素二糖的液相色谱分离和电喷雾质谱表征

肝素酶属于一种能以裂解方式降解肝素或硫酸乙酰肝素的酶类.来源不同的肝素酶具有不同的催化降解特性,产生不同类型的肝素寡糖混合物[1].本实验室从自鞘胺醇杆菌中分离纯化得到了一种新型内切肝素酶[2],其对肝素和硫酸乙酰肝素有着较广的底物特异性.为进一步了解该酶的催化机制,对肝素的降解特性,使用该酶降解了猪肠粘膜肝素,对降解产物进行了超滤、色谱分离和电喷雾质谱表征,获得了一些很有意义的结果.     

有机金属钌抗癌药物与G-四链体DNA的相互作用研究

Guanine-rich sequence TTAGGG can form G-quadruplex(G4) at the end of human telomeres, which protect chromosomal ends from unwanted recombination and degradation and inhibit the activity of telomerase enzyme, The telomerase was shown to be active in 85%-90% of human cancer cells, but inactive in healthy and somatic cells. DNA is the potential target of organometallic ruthenium(II) anticancer complexes. It is of great importance to study the interaction of ruthenium complex with the senior structural DNA G4. The present work focused on investigating the interactions between organometallic ruthenium complexes and G-quadruplex. The pilot studies show that NH4^＋ can stabilize the G4 structure to reduce the binding of biphenyl ruthenium complexes to guanine bases, but the inhibitory effects disappeared as the concentration of ruthenium complexes increases. This result suggests that the coordination of ruthenium complexes may distort and even unwind the G-quadruplex so that further coordination of ruthenium to the linear DNA fragment occurred.