Synthesis and Biological Activities of N-Phosphoryl Branched Peptides

A series of N-phosphoryl branched peptides were synthesized by coupling of various N-phosphoryl amino acids to L-Lysine methyl ester, and their structures were confirmed by 31P NMR, 1H NMR, MS and elemental analysis. The results of cell biological tests indicated that compound 1d and 1e obviously inhibited the growth of both K562 and A2780 cells.

Theoretical Study on the Activity of a-COOH and b-COOH of N-Phosphoryl Aspartic Acids

The bio-mimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. The difference of reactivity between a-COOH and b-COOH in phosphoryl aspartic acid was studied by theoretical study (Hartree-Fock and Density Functional methods) in this paper. The intermediates II containing five-membered ring were more stable than III with six-membered ring. While for intermediates III, the isomers with six-membered ring in apical-equatorial spanning arrangement were more stable than those with di-equatorial spanning arrangement. At B3LYP/6-31G** level, it was shown that transition states IV and V involving a-COOH or b-COOH group had energy barriers of DE = 58.67 kJmol-1 and 103.94 kJmol-1, respectively. These results were in agreement with the experimental data. So the a-COOH group was involved in form of the intramolecular penta-coordinate phosphoric-carboxylic mixed anhydride intermediates, but not b-COOH group.

Interaction between N-phosphoryl-α-,β-and γ-amino acids and nucleosides

The reactions of four different N-（O,O＇-diisopropyl） phosphoamino acids （DIPP-aa）, such as N-phosphoryl-L-α-alanine （DIPP- L-α-Ala）, N-phosphoryl-D-α-alanine （DIPP-D-α-A1a）, N-phosphoryl-β-alanine （DIPP-β-A1a） and N-phosphoryl-γ-amino butyric acid （DIPP-γ-Aba）, and four nucleosides, adenosine （A）, guanosine （G）, cytidine （C） and uridine （U）, were studied by electrospray ionization tandem mass spectrometry （ESI-MS/MS） and HPLC/ESI-MS. DIPP-L-α-A1a and DIPP-D-α-A1a produced the same phosphorylated nucleosides, dinucleotides and phosphoroligopeptide. However, DIPP-β-A1a and DIPP-γ-Aba gave no relevant products.

INTRAMOLECULAR β-CARBOXYLIC ACTIVATING OF N-PHOSPHORYL ASPARTIC ACID

The β-carboxylic group plays an important role in the peptide formation,esterification and the ester exchange at the phosphoryl group of N-phosphorylated aspartic acid.

RNA Cleavage by N-Phosphoryl Serine in Histidine Buffer

In the presence of histidine, N-(O,O-diisopropyl)phosphoryl serine could catalyze the cleavage of RNA in aqueous solution at neutral pH. The results were detected by sub-marine agarose gel electrophoresis and capillary zone electrophoresis. It was found that at high concentration histidine could cleave the RNA slightly. While the participation of DIPP-Ser could significantly accelerate the cleavage reaction. N-phosphodipeptide---N-(O,O-diisopropyl) Ser-His are proposed to be involved in the mechanism.

蛋白质N-磷酸化修饰富集方法进展

蛋白质磷酸化作为一种最普遍和最重要的翻译后修饰调控着几乎所有的生命过程。随着高效富集方法和生物质谱技术的快速发展,低丰度的蛋白质O-磷酸化修饰获得了规模化鉴定,从而使其生物学功能得到较为透彻的研究。而发生在组氨酸、赖氨酸和精氨酸侧链氨基的N-磷酸化修饰,由于P-N键化学稳定性差,导致其在酸和热条件下不稳定。而目前依赖酸性条件的O-磷酸化富集方法难以适用N-磷酸化富集,导致蛋白质N-磷酸化生物功能研究严重滞后。因此,迫切需要发展针对蛋白质N-磷酸化的高效富集方法。本文首先介绍了蛋白质N-磷酸化的结构特征和已报道的生物学功能,重点综述并分析了近20年来蛋白质N-磷酸化修饰富集方法,并对每一种富集方法的优缺点进行了评述,最后对潜在的富集方法进行了展望。

Orientation of the peptide formation of N-phosphoryl amino acids in solution

The peptide formation of N-phosphoryl aminoacids with amino acids proceeds in aqueous solution withoutany coupling reagents. After being separated in sephadex gelcolumn, the phosphoryl dipeptides were analyzed by theelectrospray ionization tandem mass spectrometry (ESIMS/MS). The result demonstrates that phosphoryl dipeptideswere datected in all the reaction systems. It is found tkat theformation of N-phosphoryl dipeptides is oriented: theN-terminal amino acid residues of the N-phosphoryl dipep-tides are from N-phosphoryl amino acids, and the peptideelongation happened at the C-terminal. Only adipeptide, noβ-dipeptide, is formed in the N-phosphoryl dipeptides,showing that α-carboxylic group is activated selectively byN-pbosphorylation. Theoretical calculation shows that thepeptide formation of N-phosphoryl amino acids might hap-pen through a pentu-coordinate carboxylic-phosphoric in-termediate in solution. These results might give some clues tothe stlidy on the origin of proteins and protein

复方芩柏汤调控ERK/JNK信号通路治疗溃疡性结肠炎的效应及机制研究

目的 研究复方芩柏汤对细胞外信号调节激酶(extracellular regulated protein kinases, ERK)/c-Jun氨基末端激酶(cJun N-terminal kinase, JNK)信号通路的调控作用,以及对溃疡性结肠炎(ulcerative colitis, UC)小鼠血清中炎症因子的影响。方法 将60只SPF级健康雄性BALB/C小鼠利用3%葡聚糖硫酸(dextran sulfate sodium, DSS)建立UC模型,造模成功后随机分为模型组(以生理盐水灌肠)、美沙拉嗪组(以0.196 g/kg美沙拉嗪药液灌肠)、复方芩柏汤组(以1.092 g/kg复方芩柏颗粒剂药液灌肠),每组20只,每天保留灌肠2次,连续3周。另取20只正常饲养小鼠作为空白组。在治疗前和治疗后第7、14、21天,观察小鼠体质量、大便性状、便血情况,并计算疾病活动指数(disease activity index, DAI),且于给药结束后进行麻醉取血并取结肠组织。采用HE染色观察各组小鼠结肠组织病理变化情况;ELISA法检测各组小鼠血清中炎症因子白细胞介素(interleukin)-22、IL-6、IL-10、肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)含量变化情况;采用Western blot法检测各组小鼠结肠组织中的p90核糖体蛋白S6激酶(p90 ribosomal protein S6 kinase, p90RSK)、JNK、磷酸化c-Jun氨基末端激酶(phosphorylated c-Jun N-terminal kinase, p-JNK)、细胞外调节蛋白激酶1/2(extracellular regulated protein kinases 1/2, ERK 1/2)、磷酸化细胞外调节蛋白激酶1/2(phospho extracellular regulated protein kinases, p-ERK 1/2)蛋白的表达。结果 在治疗的第7、14、21天,美沙拉嗪组、复方芩柏汤组小鼠体质量均明显高于模型组(P<0.05,P<0.01),DAI评分明显低于模型组(P<0.05,P<0.01)。光镜下,与模型组相比,美沙拉嗪组及复方芩柏汤组小鼠结肠组织病理改变呈不同程度的恢复,炎症浸润减轻。给药结束后,与空白组比较,模型组p90RSK、p-JNK、p-ERK 1/2蛋白以及IL-6、TNF-α蛋白表达明显升高(P<0.01);与模型组比较,美沙拉嗪组和复方芩柏汤组p90RSK、p-JNK、p-ERK 1/2蛋白以及IL-6、TNF-α蛋白表达明显降低(P<0.05,P<0.01),抗炎因子IL-22、IL-10含量明显升高(P<0.01)。结论 复方芩柏汤可能通过抑制ERK/JNK信号通路,促进抗炎因子IL-22、IL-10的表达,抑制促炎因子IL-6、TNF-α的表达,减少肠道炎症反应,促进肠上皮细胞增殖,改善肠黏膜屏障,促进UC小鼠肠道黏膜组织损伤修复。

Hydrolysis Reaction of N-Phosphoryl-α-, β- and γ-amino Acids Studied by HPLC

The hydrolysis reactions of N-（O,O＇diisopropyl）phosphoryl-L-α-alanine （DIPP-L-α-Ala）, N-（O,O＇diisopropyl）- phosphoryl-D-α-alanine （DIPP-D-α-Ala）, N-（O,O＇-diisopropyl）phosphoryl-β-alanine （DIPP-β-Ala） and N-（O,O＇-diisopropyl）phosphoryl-γ-amino butyric acid （DIPP-γ-Aba）, were studied by HPLC and their hydrolysis reaction kinetic equations were obtained. Under acid conditions, the reaction rate of DIPP-L-α-Ala was close to that of DIPP-D-α-Ala and the same rule was true between DIPP-β-Ala and DIPP-γ-Aba. Meantime, the reaction rate of DIPP-L/D-α-Ala was as 10 times as that of DIPP-β-Ala or DIPP-γ-Aba. Under basic conditions, the hydrolysis reactions of DIPP-β-Ala and DIPP-γ-Aba almost did not take place and the reaction rate of DIPP-L/D-α-Ala was about 1/10 of that under acid conditions. Moreover, theoretical calculation further illuminated the differences of the hydrolysis rate from the view of energy. The results would provide some helpful clues to why nature chose a-amino acids but not other kinds of analogs as protein backbones.

电针对脑缺血大鼠前扣带皮质HMGB1和p-JNK蛋白表达的影响

目的:观察电针对脑缺血大鼠前扣带皮质高迁移率族蛋白1(high mobility group protein 1,HMGB1)和磷酸化的c-Jun氨基酸末端激酶(phosphorylated c-Jun N-terminal kinase,p-JNK)的表达影响,探讨电针对脑缺血大鼠前扣带皮质的保护作用及机制。方法:将24只雄性SD大鼠随机分为假手术组、模型组、电针组和假电针组,6只/组。采用右侧大脑中动脉栓塞法制备脑缺血大鼠模型,电针组选取“百会”穴、左侧“足三里”穴进行电针刺激,1次/d,30 min/次,持续14 d;假电针组仅浅刺入两穴位皮下,接电针仪但不通电。采用Longa评分评估各组大鼠神经功能损伤情况;Nissl染色观察右侧前扣带皮质神经元的形态与分布情况;免疫组化检测右侧前扣带皮质HMGB1和p-JNK蛋白的表达情况。结果:与假手术组相比,模型组和假电针组大鼠神经功能缺损评分升高(P<0.01),右侧前扣带皮质区Nissl阳性神经元数量减少(P<0.01),HMGB1和p-JNK蛋白表达增加(P<0.01);与模型组相比,电针组大鼠在脑缺血第7天、14天时神经功能缺损评分降低(P<0.05),Nissl阳性神经元数量增加(P<0.01),HMGB1和p-JNK蛋白表达降低(P<0.01)。结论:电针可能通过抑制脑缺血后HMGB1和p-JNK的过表达,减轻前扣带皮质的损伤。

Elucidation of O-Phosphoryl and N-Phosphoryl Amino Acids by Electrospray Ionization Tandem Mass Spectrometry

Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Be- sides N-diisopropyloxyphosphoryl amino acids (N-DIPP-AA), O-phospho- and O-diisopropyloxyphosphoryl amino acids (O-DIPP-AA) were studied and compared to N-DIPP-AA. The fragmentation pathways of [M+H]+, [M+Na]+ and [M-H]- ions of phosphoryl amino acids were summarized. In addition to several similar patterns, each of them showed its characteristic fragmention.

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. It has 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.

N-phosphoryl amino acid models for P–N bonds in prebiotic chemical evolution

Post-translational modification of proteins by N-phosphorylation of the basic amino acid residues plays important roles in biological processes. The high-energy P–N bond might have contributed to the evolution of prebiotic chemistry. N-phosphoryl amino acids(PAAs) can serve as interesting small molecular models for the study of P–N bonds in prebiotic chemical evolution. PAAs are capable of simultaneously producing several important biomolecules such as polypeptides and oligonucleotides under mild reaction conditions. In this review, we describe the chemistry of PAAs, discusse their likely prebiotic origins and their reactivity and how they relate to biological P–N bond species. We also depict a possible prebiotic scenario mediated by PAAs in which PAAs may have acted as one of the essential forces driving prebiotic biomolecules to the first protocell.

N-二异丙氧磷酰化氨基酸的合成

以亚磷酸二异丙酯为磷酰化试剂、次氯酸钠为氯代试剂首次对 2 0种常见的α 氨基酸进行了磷酰化 .通过添加适量四丁基溴化铵为相转移催化剂 ,使用过量的亚磷酸二异丙酯以补偿其在强碱环境中的水解 ,从而提高了反应产率 .所得产物经核磁共振谱。

磷酰化氨基酸的特性及应用前景

综述了磷酰化氨基酸的研究进展 .磷酰化氨基酸能够发生自身活化成肽、成酯、磷上酯交换和磷酰基的N→O迁移等化学反应 ,对解释一些生命现象和探讨生命起源具有重要的作用 ,同时 ,在生物技术。