Wright K A, Hong H
Department of Zoology, University of Toronto, Ontario, Canada.
J Parasitol. 1988 Jun;74(3):440-51.
The accessory layer of the cuticle of infective larvae of Trichinella spiralis has been studied with electron microscopy using cytochemical techniques and chemical extractions. The accessory layer lacks negative charges and carbohydrates demonstrable in vivo. Staining with ruthenium red and tannic acid is interpreted as being consistent with their reactions with phospholipids. Freeze fractures demonstrate an external layer of granules that can be partially released by means of detergents (CTAB and SDS). The granules are considered to be proteins. Their removal makes the worms acid sensitive and prevents them from infecting mice. Extraction of whole worms with ethanol, acetone and methanol (via reaction with 2,2-DMP), or chloroform and methanol destroys an internal layer of filaments. Thin-layer chromatography of chloroform/methanol extracts showed principally ethanolamine phospholipids from the surface of the worms. A model is presented for the molecular organization of the accessory layer. Ethanolamine phospholipids are suggested to occur as tubular micelles. Proteins may attach to these by lipophilic moieties and perhaps by a cryptic sugar group (demonstrated by others) that may penetrate into the hydrophilic core of the lipid micelles.
利用细胞化学技术和化学提取方法，通过电子显微镜对旋毛虫感染性幼虫角质层的附属层进行了研究。附属层缺乏体内可证实的负电荷和碳水化合物。用钌红和单宁酸染色被解释为与它们与磷脂的反应一致。冷冻断裂显示有一层外部颗粒，这些颗粒可以通过去污剂（十六烷基三甲基溴化铵和十二烷基硫酸钠）部分释放出来。这些颗粒被认为是蛋白质。去除这些颗粒会使蠕虫对酸敏感，并阻止它们感染小鼠。用乙醇、丙酮和甲醇（通过与2,2 -二甲基吡啶反应）或氯仿和甲醇对整条蠕虫进行提取会破坏一层内部细丝。氯仿/甲醇提取物的薄层色谱主要显示来自蠕虫表面的乙醇胺磷脂。提出了一个附属层分子组织的模型。乙醇胺磷脂被认为以管状胶束的形式存在。蛋白质可能通过亲脂部分以及可能通过一个可能渗透到脂质胶束亲水核心的隐蔽糖基（其他人已证明）附着在这些磷脂上。
