†College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, 43 Yindou Road, Xiamen, Fujian 361021, China.
‡Agriculture Research Service, Southern Regional Research Center, U.S. Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, United States.
J Agric Food Chem. 2015 Jul 15;63(27):6271-82. doi: 10.1021/acs.jafc.5b01318. Epub 2015 Jun 30.
Myosin light chain (MLC) plays a vital role in cell and muscle functions and has been identified as an allergen in shrimp. In this study, MLC with a molecular mass of 18 kDa was purified from crayfish (Procambarus clarkii) muscle. Its physicochemical characterization showed that the purified MLC is a glycoprotein with 4.3% carbohydrate, highly stable to heat, acid-alkali, and digestion, and weakly retains IgE-binding activity when its secondary structure was altered. Serological assays suggested that conformational epitopes predominate over linear epitopes in the purified MLC. Two isoforms of the MLC gene (MLC1 and MLC2) were cloned, and the purified MLC was identified as MLC1. Analysis of the secondary and tertiary structures of the MLCs indicated that MLC1 has four conformational epitopes and three linear epitopes, whereas MLC2 had a major conformational epitope and three linear epitopes. These results are significant for understanding hypersensitization of humans to crayfish.
肌球蛋白轻链（MLC）在细胞和肌肉功能中起着至关重要的作用，并且已被鉴定为虾中的过敏原。在这项研究中，从小龙虾（Procambarus clarkii）肌肉中纯化出分子量为 18 kDa 的 MLC。其理化特性表明，纯化的 MLC 是一种糖蛋白，含有 4.3%的碳水化合物，对热、酸碱和消化具有高度稳定性，并且当其二级结构发生改变时，仍保留较弱的 IgE 结合活性。血清学检测表明，在纯化的 MLC 中，构象表位占优势，而非线性表位。克隆了两种肌球蛋白轻链基因（MLC1 和 MLC2），并鉴定纯化的 MLC 为 MLC1。对 MLCs 的二级和三级结构分析表明，MLC1 具有四个构象表位和三个线性表位，而 MLC2 具有一个主要的构象表位和三个线性表位。这些结果对于理解人类对小龙虾过敏的机制具有重要意义。
