来源于天然产物的基质金属蛋白酶(MMPs)抑制剂

基质金属蛋白酶（MMPs）参与一系列重大疾病的病理过程,基质金属蛋白酶抑制剂具有广阔的药用前景。本文概述了基质金属蛋白酶抑制剂的研究历史和最新的研究理念。重点回顾总结了天然产物中基质金属蛋白酶的活性抑制成分和对基质金属蛋白酶转录表达抑制的天然产物成分以及这些化合物的抗癌效果。     

类肽与金属蛋白酶抑制剂类抗肿瘤药物研究进展

类肽作为天然活性肽的结构或功能模拟物,具有3个优点：一是能够保留天然肽的底物功能,二是可改善其代谢性质,三是可提高其作用的靶向专一性等特点．高活性的类肽分子设计可通过构象限定、结构改造和非肽模拟物设计的构思等多种手段实现．目前肿瘤化疗药物开发的研究热点已由细胞毒药物转向靶向治疗药物,在肿瘤发生发展过程中起关键作用的许多蛋白酶和肽酶陆续被发现,因此类肽作为潜在的肿瘤化疗药物已倍受关注,而如何设计具有抗肿瘤活性的小分子类肽酶抑制剂则已成为研究的热点．本课题组多年来一直致力于研究开发APN、MMPs及HDACs的小分子类肽抑制剂作为靶向抗肿瘤药物先导物．这三种锌离子依赖性金属蛋白酶在肿瘤的生长侵袭转移、血管生成和基质降解等发展进程中起着关键作用,靶向于该类生物靶点的小分子类肽抑制剂具有开发成为高选择性抗肿瘤药物的巨大潜力．     

基质金属蛋白酶与天然黄酮醇类药物抑制剂识别机理的光谱学研究

基质金属蛋白酶(Matrix metalloproteiriases, MMPs)是肿瘤细胞对正常组织的侵袭和转移过程中重要的调节因子, 可以水解多种细胞内、细胞外及细胞膜上的底物, 因而影响着多种细胞的行为.当MMPs表达异常时, 很多种病理会改变甚至恶化, 因此, MMPs已成为近年来备受关注的一类抗肿瘤药物靶标蛋白酶. 选用MMPs的几种天然黄酮醇类药物小分子抑制剂,利用荧光滴定光谱和紫外-可见(UV-Vis)吸收光谱相结合, 研究了它们与MMPs家族成员之一MMP-16之间的分子识别和作用机理. 研究结果表明, 这几种黄酮醇化合物不但对MMP-16显示出了较强的结合能力, 而且在结合模式、结合比和抗氧化性能等多方面都表现出了很强的结构-性能差异.     

基质金属蛋白酶的新型抑制剂效能的理论研究

采用分子力学和分子动力学方法, 考察了MMPs抑制剂、焦性没食子酸(Pyrogallic acid)和杨梅黄酮(Myricetin)与MMP-7的具体结合方式以及相互作用的情况. 研究结果表明, 在与MMP-7结合时, 杨梅黄酮比焦性没食子酸具有更高的亲合性, 因此杨梅黄酮对MMP-7有更好的效能, 这与实验测得的活性顺序相符. 另外, 密度泛函理论的计算结果表明, 此类抑制剂能够通过ZBG以单配位的形式与MMPs的Zn2+相互作用. 理论计算的结果可能有助于抑制剂的设计及其效能的改善.     

双膦酸化合物对基质金属蛋白酶的抑制效应及机理

根据基质金属蛋白酶(MMPs)的活性位点附近三维空间结构, 设计合成了4种双膦酸类化合物, 利用酶促反应动力学方法对比测试了双膦酸化合物及阿伦磷酸钠(Alendronate)对MMPs的抑制效果; 结合分子对接方法以及荧光滴定光谱研究了双膦酸化合物与MMPs的分子识别和作用机理, 并得到了二者的结合模型.     

α-卤代丁二酰氧肟酸类基质金属蛋白酶抑制剂的合成及活性评价

基质金属蛋白酶(MMPs)是一族Zn2+依赖的蛋白水解酶. 该族酶的过度表达与多种病理过程密切相关, 因此其抑制剂可用于这些疾病的治疗. 本文设计合成了15个α-卤代丁二酰氧肟酸类新型基质金属蛋白酶抑制剂, 经核磁共振氢谱和质谱进行了结构表征, 并以伊洛马司他(Ilomastat)为阳性对照, 分别测定了它们对基质金属蛋白酶MMP-2和MMP-9的体外抑制活性. 结果显示, 4个化合物对MMP-2的抑制活性与阳性对照相当; 5个化合物对MMP-9的抑制活性与对照药相当.     

同轴电喷-去模板法制备具有金属基质蛋白酶响应性的纳米载体

通过化学键偶联的形式在聚乳酸(PLA)分子链中引入了可被金属基质蛋白酶(MMP-2)特异性降解的多肽peptide(GPLGIAGQ)单元,得到具有金属基质蛋白酶响应性的聚合物PLA-b-peptide-b-PLA.通过同轴电喷方法制备得到以PLA-b-peptide-b-PLA和抗肿瘤药物DOX的混合物作为内核,亲水性聚乙二醇(PEG)作为外壳的,具有核-壳结构的载药微球.其中水溶性的PEG壳层可在水环境中迅速脱除,将载药微球的尺寸从微米级减小到纳米尺度,可以达到药物载体系统在输运的循环过程中的尺寸递减.制备的纳米载体可在金属基质蛋白酶存在的环境中,响应性释放所包载的抗肿瘤药物,实现药物的控制释放.     

基质金属蛋白酶活性中心肽段的合成及纯化

基质金属蛋白酶(MMPs)是一类生物活性依赖于钙锌离子,能降解细胞外基质(extracellar matrix,ECM)的酶家族.目前已发现26个成员,越来越多的研究表明,MMPs在肿瘤侵袭转移中起着重要作用,此作用不仅仅限于它有利于细胞外基质的降解,还对肿瘤微环境的维持和促进肿瘤生长起着重要作用[1].     

潜在的大环锌金属蛋白酶抑制剂的设计与合成

A series of succinate-derived macrocyclic amides 1 were synthezized using ring-closing metathesis in the keystep.The substrate scope includes tings of 11 to 14 members.The cyclic dicarboxylic acids 1 represent a family ofnew model compounds for potential zinc metalloprotease inhibitors.The metathesis precursors were provided byamide coupling of tert-butyl 3-earboxyhex-5-enoate 2 with numerous side chain alkenylated amino acid esters ofgeneral type 3 derived from L-tyrosine and L-cysteine.     

Zn(Ⅱ)金属有机骨架作为基质金属蛋白酶模拟物催化水解微囊藻毒素-LR

以3-氨基-1,2,4-三氮唑-5-羧酸（Hatz）和1,3,5-苯三甲酸（H₃btc）为配体,制备了模拟基质金属蛋白酶（MMPs）结构的纳米片状Zn（Ⅱ）金属有机骨架Zn-MOF-1-NS。Zn-MOF-1-NS能成功实现对微囊藻毒素（MC-LR）肽键的水解。在常温条件下,7.5 h内Zn-MOF-1-NS催化水解了82.6%的MC-LR（k=0.23 h^-1）,远高于目前报道的具有最高水解效率的菱铁矿（k=0.04 h^-1）。研究发现,在该体系中即使添加10倍剂量的腐殖酸,也不会显著阻碍MC-LR的水解,证明Zn-MOF-1-NS对MC-LR的水解具有显著的选择性。通过原位衰减全反射傅里叶变换红外光谱（in-situ ATR-FTIR）、X射线光电子能谱（XPS）分析、理论计算以及与非羧基对应物的比较,发现Zn-MOF-1-NS表面Zn（Ⅱ）位点和羧基共同参与了MC-LR肽键的水解。     

Design and Structural Evolution of Matrix Metalloproteinase Inhibitors

Matrix metalloproteinases (MMPs) are involved in a multitude of severe diseases. Despite MMPs being considered druggable targets, past drug-discovery programs have not delivered the anticipated clinical benefits. This review examines the latest structural evolution of small-molecule inhibitors of MMPs, with a focus on the development of novel chemical entities with improved affinity and selectivity profiles. X-ray crystallographic data of the protein targets and cocrystal structures with inhibitors proved to be key for the success achieved during this ambitious endeavor. An evolutionary view on the structural diversity generated for this class of molecules is provided. This encouraging development paves the way for the clinical utilization of this class of highly relevant therapeutic targets. The structure-based design of superior MMP inhibitors highlights the power of this technique and displays strategies for the development of treatment options based on the modulation of challenging drug targets.     

Structure‐Based Design of Inhibitors of the Aspartic Protease Endothiapepsin by Exploiting Dynamic Combinatorial Chemistry

Structure‐based design (SBD) can be used for the design and/or optimization of new inhibitors for a biological target. Whereas de novo SBD is rarely used, most reports on SBD are dealing with the optimization of an initial hit. Dynamic combinatorial chemistry (DCC) has emerged as a powerful strategy to identify bioactive ligands given that it enables the target to direct the synthesis of its strongest binder. We have designed a library of potential inhibitors (acylhydrazones) generated from five aldehydes and five hydrazides and used DCC to identify the best binder(s). After addition of the aspartic protease endothiapepsin, we characterized the protein‐bound library member(s) by saturation‐transfer difference NMR spectroscopy. Cocrystallization experiments validated the predicted binding mode of the two most potent inhibitors, thus demonstrating that the combination of de novo SBD and DCC constitutes an efficient starting point for hit identification and optimization.     

Fragment Linking and Optimization of Inhibitors of the Aspartic Protease Endothiapepsin: Fragment‐Based Drug Design Facilitated by Dynamic Combinatorial Chemistry

Fragment‐based drug design (FBDD) affords active compounds for biological targets. While there are numerous reports on FBDD by fragment growing/optimization, fragment linking has rarely been reported. Dynamic combinatorial chemistry (DCC) has become a powerful hit‐identification strategy for biological targets. We report the synergistic combination of fragment linking and DCC to identify inhibitors of the aspartic protease endothiapepsin. Based on X‐ray crystal structures of endothiapepsin in complex with fragments, we designed a library of bis‐acylhydrazones and used DCC to identify potent inhibitors. The most potent inhibitor exhibits an IC₅₀ value of 54 nm , which represents a 240‐fold improvement in potency compared to the parent hits. Subsequent X‐ray crystallography validated the predicted binding mode, thus demonstrating the efficiency of the combination of fragment linking and DCC as a hit‐identification strategy. This approach could be applied to a range of biological targets, and holds the potential to facilitate hit‐to‐lead optimization.     

Δ8(14)-Ergostenol Glycoside Derivatives Inhibit the Expression of Inflammatory Mediators and Matrix Metalloproteinase

Arthritis is a chronic inflammatory disease accompanied by pathological reactions such as swelling, redness, fever, and pain in various joint areas. The drugs currently available to treat arthritis are associated with diverse side-effects. Therefore, there is a need for safer and more effective treatments to alleviate the inflammation of arthritis with fewer side-effects. In this study, a new sterol, Δ⁸⁽¹⁴⁾-ergostenol, was discovered, and its glycosides were synthesized and found to be more efficient in terms of synthesis or anti-inflammatory activity than either spinasterol or 5,6-dihydroergosterol is. Among these synthetic glycosides, galactosyl ergostenol inhibited the expression of inflammatory mediators in TNF-α-stimulated FLS and TNF-α-induced MMPs and collagen type II A1 degradation in human chondrocytes. These results suggest the new galactosyl ergostenol as a treatment candidate for arthritis.     

Application of Fragment‐Based Screening to the Design of Inhibitors of Escherichia coli DsbA

The thiol‐disulfide oxidoreductase enzyme DsbA catalyzes the formation of disulfide bonds in the periplasm of Gram‐negative bacteria. DsbA substrates include proteins involved in bacterial virulence. In the absence of DsbA, many of these proteins do not fold correctly, which renders the bacteria avirulent. Thus DsbA is a critical mediator of virulence and inhibitors may act as antivirulence agents. Biophysical screening has been employed to identify fragments that bind to DsbA from Escherichia coli. Elaboration of one of these fragments produced compounds that inhibit DsbA activity in vitro. In cell‐based assays, the compounds inhibit bacterial motility, but have no effect on growth in liquid culture, which is consistent with selective inhibition of DsbA. Crystal structures of inhibitors bound to DsbA indicate that they bind adjacent to the active site. Together, the data suggest that DsbA may be amenable to the development of novel antibacterial compounds that act by inhibiting bacterial virulence.     

吲哚马来酰亚胺类蛋白激酶C抑制剂的研究进展

吲哚马来酰亚胺类化合物是对星型孢菌素进行结构改造而得到的一类新型蛋白激酶C抑制剂. 对近年来吲哚马来酰亚胺类化合物在结构修饰、合成和生物活性等方面的研究进行了总结和概述, 重点介绍了吲哚马来酰亚胺类化合物的合成方法, 讨论了各种合成方法的优缺点.     

Design and Synthesis of Matrix Metalloprotease Photoaffinity Trimodular Probes

To explore the molecular mechanism of the matrix metalloproteinases (MMPs) in tumor processes, two photoaffinity trimodular probes were designed and synthesized based on the structure activity relationship and the following photoaffinity labelling experiments afforded positive results.