Honkanen R E, Stapleton J D, Bryan D E, Abercrombie J
Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile 36688, USA.
Toxicon. 1996 Nov-Dec;34(11-12):1385-92. doi: 10.1016/s0041-0101(96)00095-5.
Diarrhetic shellfish poisoning (DSP) is a serious and globally widespread phytoplankton-related seafood illness. Although DSP is rarely life-threatening, it causes incapacitating diarrhea and vomiting with no known medical treatments. In addition, phytoplankton producing DSP toxins have been identified in temperate coastal waters worldwide, and their numbers may be increasing as a result of coastal eutrophication. The toxic effects of the major DSP toxins, okadaic acid and dinophysistoxin-1 (35-methylokadaic acid), appear to originate from their inhibitory activity against a family of structurally related serine/threonine protein phosphatases (PSPases). In particular, the inhibition of essential PSPases (e.g. PP1 and PP2A) has catastrophic consequences in most eukaryonic cells. Exploiting the potent inhibitory property of the DSP toxins, we have developed an enzyme-based assay (PP2A assay) capable of detecting both okadaic acid and dinophysistoxin-1 in nanogram amounts. The assay employs purified PP2A, which has an extremely high affinity for both DSP toxins. This provides the PP2A assay with a level of sensitivity comparable to, or surpassing, that of most monoclonal antibody probes. To evaluate the PP2A assay as a means of detecting contaminated shellfish, a series of spike recovery experiments was conducted. The findings from these studies suggest that the PP2A assay has the potential for development into a rapid and relatively simple method for detecting PSPase inhibitors in crude extracts produced from shellfish.
腹泻性贝类中毒（DSP）是一种严重且在全球范围内广泛存在的与浮游植物相关的海鲜疾病。尽管DSP很少危及生命，但它会导致使人丧失能力的腹泻和呕吐，且目前尚无已知的医学治疗方法。此外，在全球温带沿海水域已鉴定出产生DSP毒素的浮游植物，并且由于沿海富营养化，它们的数量可能正在增加。主要的DSP毒素，冈田酸和鳍藻毒素-1（35-甲基冈田酸）的毒性作用似乎源于它们对一类结构相关的丝氨酸/苏氨酸蛋白磷酸酶（PSPases）的抑制活性。特别是，对必需的PSPases（例如PP1和PP2A）的抑制在大多数真核细胞中会产生灾难性后果。利用DSP毒素的强大抑制特性，我们开发了一种基于酶的检测方法（PP2A检测法），能够检测纳克量的冈田酸和鳍藻毒素-1。该检测方法使用纯化的PP2A，它对两种DSP毒素都具有极高的亲和力。这使得PP2A检测法具有与大多数单克隆抗体探针相当或更高的灵敏度。为了评估PP2A检测法作为检测受污染贝类的手段，进行了一系列加标回收率实验。这些研究的结果表明，PP2A检测法有潜力发展成为一种快速且相对简单的方法，用于检测贝类粗提物中的PSPase抑制剂。
