Minea Radu, Swenson Stephen, Costa Fritz, Chen Thomas C, Markland Francis S
Pivotal BioSciences, Inc., Keck School of Medicine, Los Angeles, Calif. 90033, USA.
Pathophysiol Haemost Thromb. 2005;34(4-5):177-83. doi: 10.1159/000092419.
Contortrostatin (CN) (Mr 13,500 Da) is a novel homodimeric disintegrin isolated from the venom of Agkistrodon contortrix contortrix (Southern Copperhead) snake and displays two RGD motifs (one on each chain), which modulate its interaction with integrins on tumor cells and angiogenic vascular endothelial cells. In previous studies, we have shown that native CN administered in a liposomal formulation exhibits potent anti-angiogenic and tumor growth inhibitory activities. Current isolation of the protein from crude venom is difficult and prohibitively expensive for translation into the clinic. In this report, we describe a method amenable to large-scale production of a soluble monomeric form of recombinant CN with biologic activity; the protein is expressed directly in the cytoplasm of an engineered bacterial system with an expression yield of approximately 20 mg/l of culture. We present here the in vitro assays as well as the anti-tumor and anti-angiogenic evaluation of liposomal recombinant CN in an orthotopic, xenograft model of human breast cancer.
扭曲素（CN）（分子量13,500道尔顿）是一种从南部铜斑蛇（Agkistrodon contortrix contortrix）毒液中分离出的新型同源二聚体去整合素，具有两个RGD基序（每条链上一个），可调节其与肿瘤细胞和血管生成性血管内皮细胞上整合素的相互作用。在先前的研究中，我们已经表明，以脂质体制剂形式给药的天然CN具有强大的抗血管生成和肿瘤生长抑制活性。目前从粗毒液中分离该蛋白既困难又成本高昂，无法用于临床转化。在本报告中，我们描述了一种适合大规模生产具有生物活性的可溶性单体形式重组CN的方法；该蛋白直接在工程化细菌系统的细胞质中表达，表达产量约为每升培养物20毫克。我们在此展示了脂质体重组CN在人乳腺癌原位异种移植模型中的体外试验以及抗肿瘤和抗血管生成评估。
