College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety, Jimei University, 43 Yindou Road, Xiamen, Fujian, China.
J Sci Food Agric. 2010 Aug 15;90(10):1614-20. doi: 10.1002/jsfa.3988.
China is the largest producer and consumer of aquatic products in the world; however, many people in China suffer from allergies upon consuming crab. Stability in simulated gastric fluid is regarded as an important parameter for the estimation of food allergenicity.
The digestive stability of allergenic protein tropomyosin (TM) and other food proteins from Chinese mitten crab in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) digestion assay systems was investigated and compared by SDS-PAGE, western blot and inhibition ELISA. In the SGF system, proteins such as the original band of myosin heavy chain (MHC) and actin were rapidly degraded within a short period of time, while TM was relatively resistant to pepsin digestion. In the SIF system, MHC was easily decomposed, while TM and actin were similarly resistant to digestion. Further study by IgE immunoblotting and inhibition ELISA using sera from crab-allergic patients indicated that allergenicity of TM was partially decreased.
Chinese mitten crab major allergen TM was resistant to pepsin while relatively susceptible to trypsin and chymotrypsin digestion. Both SDS-PAGE using purified TM and western blot using myofibrillar proteins indicated that the degradation pattern of TM by SGF and SIF was not affected by the presence of other myofibrillar proteins. Inhibition ELISA results revealed that proteinase digestion is effective in reducing the allergenicity of crab TM.
中国是世界上最大的水产品生产国和消费国；然而，许多中国人在食用蟹类后会过敏。在模拟胃液中的稳定性被认为是评估食物变应原性的一个重要参数。
通过 SDS-PAGE、western blot 和抑制 ELISA 研究和比较了中华绒螯蟹致敏蛋白原肌球蛋白（TM）和其他食物蛋白在模拟胃液（SGF）和模拟肠液（SIF）消化测定系统中的消化稳定性。在 SGF 体系中，肌球蛋白重链（MHC）和肌动蛋白等原始带的蛋白质在短时间内迅速降解，而 TM 对胃蛋白酶消化相对耐受。在 SIF 体系中，MHC 容易分解，而 TM 和肌动蛋白同样不易被消化。使用蟹过敏患者的血清进行 IgE 免疫印迹和抑制 ELISA 的进一步研究表明，TM 的变应原性部分降低。
中华绒螯蟹主要过敏原 TM 对胃蛋白酶有抗性，而对胰蛋白酶和糜蛋白酶消化相对敏感。使用纯化的 TM 进行 SDS-PAGE 和使用肌原纤维蛋白进行 western blot 均表明，SGF 和 SIF 中 TM 的降解模式不受其他肌原纤维蛋白的影响。抑制 ELISA 结果表明蛋白酶消化可有效降低蟹 TM 的变应原性。
