结合丝组二肽的树状多肽对λDNA的切割

以Fmoc手工固相合成法合成了以多聚赖氨酸为骨架, 表面结合丝组二肽的四分支和二分支树状多肽, 以高效液相色谱提纯, 电喷雾电离质谱表征, 并通过凝胶电泳法研究了其对λDNA的切割活性.     

丝组二肽对DNA切割作用的QM-MM研究

运用QM-MM方法对丝组二肽切割DNA作用的机理进行了研究．通过计算得到了丝组二肽与DNA形成多氢键作用的有效分子识别模型及相关分子结构参数，从理论上解释了丝组二肽与DNA通过形成五配位磷中间体而使磷酸二酯键发生水解，从而使得DNA被切断的作用机理。     

丝组二肽——现代蛋白酶分子进化过程中的原始雏形

系统阐述了我们实验室近十五年来对丝组二肽的生物活性的研究.丝组二肽是目前报道的具有多种切割活性的最小活性肽,它不仅能够切割DNA,而且可以切割蛋白质及羧酸酯.丝组二肽是迷你的磷酸酯酶和蛋白水解酶,是现代蛋白酶分子进化过程中的原始雏形.     

从磷酰化氨基酸到丝组二肽

Phosphorus is one of the important elements for life, which participates in various biochemical processes. L-Amino acids are the basic structural units of proteins. N-phosphorylation of amino acids makes them be activated and become one kind of "micro activating enzyme", which possesses a variety of biochemical reaction activities, such as peptide formation. Based on the peptide formation reaction of N-phosphoryl amino acids, L-seryl-L-histidine dipeptide (Seryl-histidine dipeptide) is produced and found that it is the smallest functional peptide with a variety of biological enzyme activities. Seryl-histidine dipeptide could be regarded as the original evolution prototype of modern hydrolytic enzyme. This paper reviews the research process from N-phosphoryl amino acids to the discovery of seryl-histidine dipeptide in detail. There are pain, confusion and joy, which fully embodies the charm of scientific exploration.     

N-（O,O-二异丙基）磷酰化丝氨酸成肽反应的立体效应研究

研究了N－（O,O－二异丙基）磷酰化－L－（或D－）丝氨酸和L－（或D－）组氨酸在水溶液中的反应及其与L－（或D－）组氨酸甲酯在DMSO中的反应,用SDS作对离子试剂,采用离子对反相高效液相色谱方法及反应产物进行分析。结果表明,所有反应体系中均有丝组二肽生成,而L－L和D－D型丝组二肽的生成量约是L－D和D－L型产物的4倍。     

Intermolecular Phosphoryl Transfer Between Serine and Histidine Residues

A novel intermolecular phosphoryl transfer from O-trimethylsilyl-N-(O, O-diisopropyl)phosphoryl serine trimethylsilyl ester to N, N‘-bis(trimethylsilyl) histidine trimethylsilyl ester wasstudied through electrospray ionization mass spectrometry (ESI-MS). It was proposed that thetransfer reaction went through penta-coordinated phosphorus intermediate.     

丝组二肽对DNA的切割作用的研究

近20年来,人工核酸切割试剂的研究一直是生物化学中最为活跃的前沿领域之一,研究人工核酸切割试剂的主要目的是合成定点切割试剂,后者是一种重要的分子生物学工具,在疾病的基团治疗、反义PCR技术等领域中有着重要的应用价值。此外,人工核酸切割试剂还可以在足迹技术和核酸高级结构的研究中用作高分辨率的化学探针。     

细胞粘附位点RGD前体二肽的化学合成与酯化

摘要利用一种新颖的化学法合成了细胞粘附位点RGD前体二肽GD(Gly-Asp). 并利用ROH-HCl法进一步完成了GD二肽乙酯化和甲酯化. 考察了GD二肽对乙醇/甲醇的摩尔比,  反应温度和反应时间对酯化收率的影响, 使GD二肽酯化的条件得到了优化, GD二肽对乙醇/甲醇的摩尔比为1∶40,  反应温度30℃,  反应时间1~2.5 h,   最大收率为80%~85%. 利用质谱分析法确证了两种GD二肽酯为Gly-Asp-(OEt)2 和Gly-Asp-(OMe)2.     

丝组二肽所含基团在其切割DNA反应中的作用

近 2 0年来 ,人工核酸切割试剂的研究一直是化学、生物化学和分子生物学中最为活跃的前沿领域之一[1,2 ] .人工核酸切割试剂可以在足迹技术和核酸高级结构的研究中用作高分辨率的化学探针 ,还可以用于合成定点切割试剂[3] .后者又被称为人工工具酶 ,是一种非常重要的分子生物学工具 ,在疾病的基因治疗、反义 PCR技术等领域中都具有重要的应用 .人工核酸切割试剂的切割机理主要有自由基机理和磷酸酯水解机理两大类 .相对于自由基机理 ,水解机理具有许多优点 ,使得水解型切割试剂具有更为广泛的应用 .对于 DNA,目前文献报道的水解型人工切…     

Polymer-assisted solution-phase parallel synthesis of dipeptide p-nitroanilides and dipeptide diphenyl phosphonates

This letter describes the parallel synthesis of dipeptide p-nitroanilides (1) and dipeptide diphenyl phosphonates (2), compounds that can be used as substrates and irreversible inhibitors for the rapid profiling of dipeptidyl peptidases. A polymer-assisted solution-phase synthesis was used for a rapid and clean coupling between easily available building blocks.     

“Click dipeptide”: A novel stationary phase applied in two-dimensional liquid chromatography

2D-HPLC is an important technique for the separation of complex samples. Developing new types of stationary phases is of great interest to construct 2D-LC systems with high orthogonality. In this study, a novel stationary phase-Click dipeptide (l-phenylglycine dipeptide) was prepared by immobilization of α-azido l-phenylglycine dipeptide on alkyne-silica via click chemistry. In the preparation of this new material, an efficient, inexpensive and shelf-stable diazo transfer reagent (imidazole-1-sulfonyl azide hydrochloride) was utilized to transfer the amino group of l-phenylglycine to corresponding azido group under mild conditions. The Click dipeptide thus prepared was confirmed by FT-IR, solid state CP/MAS ¹³C NMR and elemental analysis. The Click dipeptide packing showed high orthogonality with C18, which reached 63.5%. An off-line 2D-RP/RPLC system was developed to analyze a traditional Chinese medicine (TCM)-Rheum Palmatum L. The results showed high orthogonality between Click dipeptide and C18 as well as great separating power in the practical separation of complex samples.     

碱基腺嘌呤与多肽酰胺间氢键作用的最佳位点

正确理解核酸碱基和蛋白质多肽间的作用机制有助于人们利用这些生物分子有效地进行分子设计,进而制备具有特殊纳米结构和功能的生物分子材料.本文优化得到了碱基腺嘌呤与N-甲基乙酰胺、甘氨酸二肽、丙氨酸二肽形成的20个氢键复合物的结构并计算了结合能,探讨了腺嘌呤与多肽酰胺间氢键作用的最佳位点.研究发现:腺嘌呤可以使用两个不同位点(A1位点和A2位点)与N-甲基乙酰胺形成N―H…N型或者N―H…O=C型氢键复合物,腺嘌呤使用A1位点与N-甲基乙酰胺形成的N―H…N型氢键复合物更稳定;二肽分子可以使用主链上两个不同位点(丙氨酸的Ala7位点和Ala5位点或者甘氨酸的Gly7位点和Gly5位点)与腺嘌呤形成含有N―H…N和N―H…O=C两条氢键的复合物,二肽分子使用Ala7或Gly7位点与腺嘌呤形成的氢键复合物更稳定;腺嘌呤与多肽间的氢键作用强于其与N-甲基乙酰胺的作用.基于分子中的原子理论与自然键轨道计算结果分析了氢键作用的本质.     

The mass spectra of N-adamantoylpeptides

The N-adamantoyl derivatives of the esters of twenty-one di-peptides and eight tri-peptides containing the amino acids glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, glutamic acid, lysine, histidine, serine, threonine, methionine, S-benzylcysteine and tyrosine were prepared and their mass spectra determined. The spectra of all compounds were suitable for amino acid sequence determination. Mixtures containing N-adamantoyl dipeptide and tripeptide methyl esters were separated by thin-layer chromatography and the components identified by high resolution mass spectrometry. The mass spectrometric features of N-adamantoyl peptide esters are discussed and compared with those of other N-acyl peptide derivatives.     

气相条件下金属离子/肽复合物电喷雾串联质谱研究

研究蛋白质与金属离子之间的相互作用的本质一直是生物学家感兴趣的课题。但蛋白结构的复杂性使得二者之间相互作用的研究难度很大,常选用氨基酸或小肽作为模型化合物进行研究^[1-4]。目前该方法的研究甩缺乏系统性。     

«Push-Pull»-Acetylene als Hilfsmittel zur Synthese von Peptiden

Peptide synthesis by Means of ‘Push-Pull’-Acetylenes ‘Push-pull’-acetylenes 1 are excellent reagents for peptide synthesis: Addition of ‘push-pull’-acetylenes to solutions of N-protected amino acids (or vice versa) gives enol esters 5 , which react selectively with the amino function of a second amino acid. In this way serine, tyrosine, 4-hydroxyproline, cysteine as well as histidine are linked to form dipeptide esters without protection of the second functional group (OH, SH or NH). The amount of racemization is very low. Similarly tri- as well as tetrapeptides are available. The versatility of the reaction is discussed.     

The Cleavage Effect of Histidyl-Lysine on RNA

Recentlytherehasbeenconsiderableinterestindevel0pingcatalyststhathydrolyticallycleavethePhosPhodiesterbackbone0fRNAsite-specificallyforthepotentialaPplicati0nstomolecularbi0l0gyandgenetheraPy"2SmallmoleculeswithRNAcleavageactivityareusedasresearchtoolsfortheinVestigationofnucleicacidstrUctUres.3'4SeveralexamPlesofoxidativecleavagecatalystshavebeenrePortCd.'MuchefforthasbeendevotedtoRNAhydIolysiscatalystSduet0theadvatgesover0xidativecleavageones.'MetaLbasedhydrolysisofRNAhasbeenreport…     

毛细管电泳法手性拆分14种二肽

以咔唑-9-乙基氯甲酸酯(CEOC)作为柱前衍生试剂,采用毛细管电泳对14种二肽进行了手性拆分。以5种二肽为代表,考察了缓冲液种类、浓度、pH值、二元手性选择剂的组合配比等因素对二肽的拆分效果,优化了实验条件。在各自的优化条件下,14种二肽手性拆分的分离度均在3.63以上,最高分离度可达43.14(Gly-Ala)。     

Proline-based Amino Pyridine Dipeptides as Efficient Organocatalysts for Direct Aldol Reaction

A series of proline-based amino pyridine dipeptide organocatalysts was synthesized and applied in direct asymmetric intermolecular aldol reaction. These catalysts showed good solubility in organic solvents, good yields (73%―97%) and enantioselectivitives(74%―94%). Among them, dipeptide organocatalyst(2) was found to be the most efficient one for the asymmetric aldol reaction between cyclohexanone and 4-nitrobeznaldehyde. After optimizing the catalytic reaction conditions, we found that the catalyst showed high yield(97%), enantioselectivity(e.e., up to 92%) and anti-diastereoselectivity(up to 95:5) at mild room temperature without any additives.     

Interactions of oxidative radicals with N-phosphoryl dipeptide derivatives

The interactions of oxidative radicals (Br2 , HO etc.) with N-phosphoryl dipeptide derivatives (NDM-TrpOMe and NDT-MetOMe) have been investigated by using pulse radiolysis at different pH values. Ithas been found that Br2 and HO radicals oxidize the Met-site and Trp-site in the dipeptide derivatives via formation of the three-electron-bonded intermediate and indolyl radical simultaneously. Then the intramolecular electron transfer along the peptide backbone occurs. The rate constants of electron transfer, k, have been determined and the reaction mechanism has been deduced.     

蛋白质二级结构的氨基酸紧邻位效应和二肽构象因子

提出了蛋白质二级结构中的氨基酸C端和N端邻位因子以及二肽构象因子. 基于对蛋白质数据库PDB105版全库的分析, 讨论了N端和C端邻位对氨基酸二级结构倾向性的影响, 讨论了二肽序的二级结构倾向性. 发现有些氨基酸的邻位因子对和二肽序对的二级结构构象因子差别较大, 表明这些氨基酸对其N端和C端邻位的影响不对称.