A novel polypeptide from shark cartilage with potent anti-angiogenic activity

Using guanidine-HCl extraction, acetone precipitation, ultra-filtration and chromatography, a novel polypeptide with potent anti-angiogenic activity was purified from cartilage of the shark, Prionace glauca. N-terminal amino acid sequence analysis and SDS-PAGE revealed that the substance is a novel polypeptide with MW 15500 (PG155). The anti-angiogenic effects of PG155 were evaluated using zebrafish embryos model in vivo. Treatment of the embryos with 20 mu g/ml PG155 resulted in a significant reduction in the growth of subintestinal vessels (SIVs). A higher dose resulted in almost complete inhibition of SIV growth, as observed by endogenous alkaline phosphatase (EAP) staining assay. An in vitro transwell experiment revealed that the polypeptide inhibited vascular endothelial growth factor (VEGF) induced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs in 20 mu g/ml PG155 significantly decreased the density of migrated cells. Almost complete inhibition of cell migration was found when HUVECs were treated with 40-80 mu g/ml PG155. PG155 (20 mu g/ml) markedly inhibited the tube formation of HUVECs and a dose-dependent effect was also found when treatment of HUVECs with PG155 at the concentration from 20 to 160 mu g/ml.

基于SPEM2XPDL模型转换的软件过程执行

SPEM(software process engineering metamodel)是国际标准化组织制定的标准元模型,正日益成为软件过程建模领域的行业标准,但在过程执行方面,SPEM还存在不足.将软件过程看作是一种特殊的工作流,提出了一种应用工作流运行机制支持软件过程执行的方法.通过将SPEM模型转换为XPDL(XML process definition language)模型,利用XPDL引擎支持SPEM模型的执行.制定了SPEM和XPDL之间的映射规则,设计了转换算法并开发了转换引擎.该方法被应用在SoftPM项目中,成功地基于XPDL引擎Shark实现了对软件过程模型的执行支持.

SPEM2XPDL模型转换研究

将软件过程技术与工作流技术相结合,严格定义了SPEM2XPDL模型转换规则,设计并实现了一个SPEM2XPDL模型转换引擎.此引擎将SPEM描述的软件过程转换为符合工作流定义(XPDL)的工作流过程,从而可基于工作流管理系统对软件过程提供执行支持.SPEM模型经引擎转换后在工作流管理系统Shark上的成功执行表明了引擎的可用性.

The complete amino acid sequence of growth hormone and partial amino acid sequence of prolactin and somatolactin from sea perch (Lateolabrax japonicus)

Growth hormone (GH), prolactin (PRL) and somatolactin (SL) were purified simultaneously under alkaline condition (pH 9.0) from pituitary glands of sea perch (Lateolabrax japonicas) by a two-step procedure involving gel filtration on Sephadex G-100 and reverse-phase high-performance liquid chromatography (rpHPLC). At each step of purification, fractions were monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and by immunoblotting with chum salmon GH. PRL and SL antisera. The yields of sea perch GH, PRL and SL were 4.2, 1.0 and 0.28 mg/g wet tissue, respectively. The molecular weights of 19,200 and 20,370 Da were estimated by SDS-PAGE for sea perch GH and PRL, respectively. Two forms of sea perch SL were found: one (28,400 Da) is probably glycosylated, while the other one (23,200 Da) is believed to be deglycosylated. GH bioactivity was examined by an in vivo assay. Intraperitoneal injection of sea perch GH at a dose of 0.01 and 0.1 mug/g body weight at 7-day intervals resulted in a significant increase in body weight and length of juvenile rainbow trout. The complete sea-perch GH amino acid sequence of 187 residues was determined by sequencing fragments cleaved by chemicals and enzymes. Alignment of sea-perch GH with those of other fish GHs revealed that sea-perch GH is most similar to advanced marine fish, such as tuna, gilthead sea bream, yellowfin porgy, red sea bream, bonito and yellow tail with 98.4, 96.2%, 95.7%, 95.2%, 94.1% and 91% sequence identity, respectively. Sea-perch GH has low identity to Atlantic cod (76.5%), hardtail (73.3%), flounder (68.4%), chum salmon (66.3%), carp (54%) and blue shark (38%). Partial amino-acid sequences of 127 of sea-perch PRL and the N-terminal of 16 amino-acid sequence of sea-perch SL have been determined. The data show that sea-perch PRL has a slightly higher sequence identity with tilapia PRL( 73.2%) than with chum salmon PRL(70%) in this 127 amino-acid sequence. (C) 2001 Elsevier Science B.V. All rights reserved.

鲨鱼软骨抗血管生成多肽的分离纯化及其生物活性

以血管生成为靶点的抗肿瘤策略是抗肿瘤领域的研究热点，目前已经发现许多天然和化学合成的抗血管生成药物。鲨鱼软骨作为抗新生血管生成因子的重要来源的研究已有20多年的历史，很多研究显示鲨鱼软骨提取物有抗血管生成活性。但鲨鱼软骨活性多肽的完整分子结构一直未见报道；鲨鱼软骨活性多肽干扰血管生成通路的信号途径尚不明确。 本文应用盐酸胍抽提、丙酮分级沉淀、超滤、凝胶层析等分离技术，从青鲨（Prionace glauca）软骨中分离纯化并鉴定了一种新的具有抗新生血管生成活性的多肽。经SDS-PAGE和N-末端氨基酸序列分析显示，该多肽分子量为15500 Da，采用蛋白数据库分析表明该多肽是一种新发现的鲨鱼软骨多肽（Polypeptide from Prionace glauca，PG155）。 体外实验显示，PG155抑制内皮细胞生长因子（vascular endothelial growth factor，VEGF）介导的人脐静脉内皮细胞（human umbilical vein endothelial cell ，HUVEC）迁移和管腔形成，并呈剂量依赖关系。200 μg/ml PG155对牛主动脉内皮细胞（Bovine Aortic Endothelial Cells，BAECs）和HUVECs及以下癌细胞，包括人肝癌细胞（human hepatoma Bel-7402 cells，Bel-7402）、 口腔上皮癌细胞（human oral epidermoid carcinoma KB cells ，KB）、人结肠癌细胞（human colon cancer HCT-18 cells，HCT-18）和人乳腺癌细胞（human breast MCF7 cancer cells ，MCF7）的增殖均无抑制作用，说明PG155无细胞毒作用。20 μg/ml PG155显著抑制HUVEC的迁移和管腔形成；40-80 μg/ml PG155 对VEGF 介导的HUVEC的迁移和管腔形成几乎完全抑制。 体内实验显示，PG155显著抑制斑马鱼胚胎模型新生血管生成，并呈剂量依赖关系。形态学观察表明PG155显著抑制斑马鱼胚胎肠下静脉（subintestinal vessels， SIVs）的生长，随着浓度的升高SIVs的生长可受到完全抑制。碱性磷酸酶染色分析显示，在一定浓度范围内，PG155随着浓度的升高对斑马鱼胚胎整体血管生成抑制作用依次增强。160 μg/ml PG155会引起斑马鱼胚胎心脏功能障碍。 由海洋生物中发现新的肿瘤新生血管生成抑制剂国内外的报道较少，我们的工作表明鲨鱼软骨可作为血管生成抑制剂的重要来源，鲨鱼软骨活性多肽PG155由于具有极低的细胞毒作用，并能抑制VEGF介导的血管生成过程，有希望成为一类新型抗肿瘤药物。