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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #316174
Title: Purification, Characterization and Analysis of the Allergenic Properties of Myosin Light Chain in Procambarus clarkia.

Author
item ZHENG, YONG-XIA - Jimei University
item CHEN, HENG-LI - Jimei University
item Maleki, Soheila
item CAO, MIN-JEI - Jimei University
item ZHANG, LING-JING - Jimei University
item SU, WEN-JIN - Jimei University
item LIU, GUANG-MING - Jimei University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2015
Publication Date: 6/30/2015
Citation: Zheng, Y., Chen, H., Maleki, S.J., Cao, M., Zhang, L., Su, W., Liu, G. 2015. Purification, Characterization and Analysis of the Allergenic Properties of Myosin Light Chain in Procambarus clarkia.. Journal of Agricultural and Food Chemistry. doi:10.1021/acs.jafc.5b01318.

Interpretive Summary: Myosin light chain (MLC) plays a vital role in cell and muscle functions, and has been identified as an allergen in closely related shellfish species. In this study, MLC with the molecular mass of 18kDa was purified from crayfish (Procambarus clarkii) muscle fibrils. Its physicochemical characterization showed that the purified MLC has a 4.3% carbohydrate content is highly stable to heat, acid–alkali, and digestion, and weakly retains IgE-binding activity when its secondary structure is altered. Immunoglobulin E (IgE) antibody from the blood of crayfish allergic individuals binds better to this muscle protein when it is folded. In this study, two types of the MLC gene (MLC1 and MLC2) were found, and the purified MLC was identified as MLC1. The protein structures of these MLCs were also analyzed, and indicated that MLC1 has four areas for antibody binding that are folded, and three that are linear; whereas, MLC2 had one folded area that is bound by antibody, and three linear areas. These results are significant for understanding the allergic reaction of humans to crayfish.

Technical Abstract: Myosin light chain (MLC) plays a vital role in cell and muscle functions and has been identified as an allergen in close species. In this study, MLC with the molecular mass of 18kDa was purified from crayfish (Procambarus clarkii) muscle fibrils. 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 is altered. Serological assays suggested that conformational IgE epitopes predominate over linear IgE epitopes in the purified MLC. Two isoforms of the MLC gene (MLC1 and MLC2) were cloned, and the purified MLC was identified as MLC1. The secondary and tertiary structures of the MLCs were also analyzed, and indicated that MLC1 has four conformational IgG 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.