Comparative study of in vitro digestibility of major allergen tropomyosin and other food proteins of Chinese mitten crab (Eriocheir sinensis).
BACKGROUND
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.


RESULTS
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.


CONCLUSIONS
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.
Liu
Guang-Ming
GM
College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety, Jimei University, 43 Yindou Road, Xiamen, Fujian, China. gmliu@jmu.edu.cn
Cao
Min-Jie
MJ
Huang
Yuan-Yuan
YY
Cai
Qiu-Feng
QF
Weng
Wu-Yin
WY
Su
Wen-Jin
WJ
D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000818:Animals; D015153:Blotting, Western; D003386:Brachyura / Q000737:chemistry*; D002681:China; D004063:Digestion; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005512:Food Hypersensitivity / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control*; D005750:Gastric Juice; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D007422:Intestines; D010434:Pepsin A / Q000378:metabolism; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D014335:Tropomyosin / Q000276:immunology / Q000378:metabolism*; D055815:Young Adult
D000199:Actins; D011506:Proteins; D014335:Tropomyosin; D007073:Immunoglobulin E; D010434:Pepsin A