State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province 214122, China.
Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA.
Food Funct. 2019 Jul 17;10(7):3934-3941. doi: 10.1039/c9fo00699k.
Shrimp tropomyosin (TM) is a glycoprotein allergen with high lysine content, however, there is little data on how deglycosylation and glycation modify the allergenicity of TM. In this work, the effects of deglycosylation (enzymatic and chemical) and glycation of TM by glucose on in vivo allergenicity and mast cell function were investigated using BALB/c mouse and RBL-2H3 mast cells. Compared with TM, after deglycosylation, the deglycosylated TMs (DGTMs) exacerbated the in vivo allergenicity and mast cell allergy response. As for the TM glycated by glucose (TM-G), glycation led to weaker allergy responses on mouse and mast cells, which might be due to glucose destroying the epitopes with glycation sites. Moreover, the glucose residues on TM-G functioned as both a resistance to prevent the accessibility of TM-G to the IgE on mast cell and masking epitopes. Therefore, deglycosylation of TM was not suitable for desensitizing TM-induced food allergy, while glycation of TM might be applied to desensitize TM allergenicity, which could provide new insight into food allergy desensitization for larger cohorts of shrimp-allergic patients.
虾肌球蛋白（TM）是一种糖蛋白过敏原，具有较高的赖氨酸含量，但关于去糖基化和糖基化如何改变 TM 的变应原性的数据很少。在这项工作中，使用 BALB/c 小鼠和 RBL-2H3 肥大细胞研究了虾肌球蛋白的去糖基化（酶和化学）和葡萄糖糖基化对体内变应原性和肥大细胞功能的影响。与 TM 相比，去糖基化后，去糖基化的 TM（DGTM）加剧了体内变应原性和肥大细胞过敏反应。对于被葡萄糖糖基化的 TM（TM-G），糖基化导致对小鼠和肥大细胞的过敏反应减弱，这可能是由于葡萄糖破坏了具有糖基化位点的表位。此外，TM-G 上的葡萄糖残基既作为阻止 TM-G 与肥大细胞上的 IgE 相互作用的抗性，也作为掩盖表位的作用。因此，TM 的去糖基化不适合用于脱敏 TM 诱导的食物过敏，而 TM 的糖基化可能适用于脱敏 TM 的变应原性，这为更大的虾过敏患者群体提供了食物过敏脱敏的新见解。
