dxy

2006年10月10日

    澳大利亚的科学家已经鉴定出一种能引起严重胃肠疾病，如食物中毒的高效价毒素。这种毒素是由某种大肠杆菌属细菌所产生的。业已证明，在1998年澳大利亚南部爆发的溶血性尿毒症（能引起急性肾衰的一种严重疾病）就是由它引起的。

    该研究小组由Adelaide大学的Adrienne Paton博士领导，还包括来自在微生物结构和功能基因组取得卓越成就的Monash大学的ARC中心的科学家和来自美国的科学家。

    来自Monash大学生物化学和分子生物学系的Travis Beddoe博士，是该研究小组的成员之一。他发现这种细菌毒素和Subtilase细胞毒素都可以使胃肠道细胞的一种必须成分失活。他说：“这种作用是特异性的，因为它能将细胞结构的必须成分一分为二，继而使其丧失功能。”

    除了明确该毒素是如何作用的，科学家们还分析出了它的三维结构，这将有助于毒素相关性疾病治疗的发展。

    Beddoe博士解释说：“这种毒素属于引起百日咳的毒素家族，百日咳是发生在儿童的一种非常严重的细菌感染性疾病。”他说该研究突破可能还会加深对Parkinson病和Alzheimer病等年龄相关的退行性疾病发展的认识，也可能运用于某些肿瘤的治疗。

    该合作研究由“全国健康和医药研究协会”与“澳大利亚研究协会”支持，其研究结果发表在最新的Nature杂志上。

注：Subtilase细胞毒素 1998年首次从澳大利亚南部产生志贺毒素的大肠杆菌 （STEC）的一个恶性菌种中分离出来的，此后又在STEC的其他几个菌种中被发现。STEC是一种人类病原体，能引起威胁生命的肠胃病。现在，研究人员已经确定了Subtilase细胞毒素产生极端毒性的机制：它能引起重要内质网伴护分子BiP的单点解理。该发现之所以引人注目，是因为，影响内质网压力响应的伴护功能的缺陷现在被发现与细胞衰老、以及包括白内障、帕金森氏综合症和阿尔茨海默氏综合症等机能退化症状密切相关。该毒素能够快速地、专一地破坏BiP功能，因此它为我们提供了一个细胞生物学新工具，使研究人员能够对这些疾病发病机理中的关键事件进行体外模拟。------来自“中国生物科技信息网”。

Scientists discover toxin that causes gastro disease
10 October 2006

Australian scientists have identified a highly potent toxin that causes severe gastrointestinal illnesses, including food poisoning.

The toxin, produced by certain strains of E. coli bacteria, has been found to be responsible for an outbreak of haemolytic uraemic syndrome, a dangerous disease that causes acute kidney failure, in South Australia in 1998.

The research team was led by Dr Adrienne Paton from the University of Adelaide, and included scientists from Monash University's ARC Centre of Excellence in Structural and Functional Microbial Genomics, and the United States.

Dr Travis Beddoe from Monash University's Department of Biochemistry and Molecular Biology, is one of the investigators who discovered that the bacterial toxin, subtilase cytotoxin, deactivates an essential component of cells in the gastrointestinal tract.

"It is unique because it cuts an essential component of the cell machinery in half, therefore disabling it," he said.

As well as learning how the toxin works, the scientists have also determined its three-dimensional structure, which will aid in the development of treatments for toxin-related diseases.

"This toxin belongs to the family of toxins that cause whooping cough, a very serious bacterial infection that affects children," Dr Beddoe said.

He said the research breakthrough may also provide insights into the development of age-related and degenerative diseases such as Parkinson's disease and Alzheimer's disease, and may be used in the treatment of some cancers.

The collaborative research was supported by the National Health and Medical Research Council and the Australian Research Council. The research findings are published in the latest issue of the journal Nature.

编辑：蓝色幻想