Proteomic analysis of amino acid metabolism differences between wild and cultivated Panax ginseng.

BACKGROUND The present study aimed to compare the relative abundance of proteins and amino acid metabolites to explore the mechanisms underlying the difference between wild and cultivated ginseng (Panax ginseng Meyer) at the amino acid level. METHODS Two-dimensional polyacrylamide gel electrophoresis and isobaric tags for relative and absolute quantitation were used to identify the differential abundance of proteins between wild and cultivated ginseng. Total amino acids in wild and cultivated ginseng were compared using an automated amino acid analyzer. The activities of amino acid metabolism-related enzymes and the contents of intermediate metabolites between wild and cultivated ginseng were measured using enzyme-linked immunosorbent assay and spectrophotometric methods. RESULTS Our results showed that the contents of 14 types of amino acids were higher in wild ginseng compared with cultivated ginseng. The amino acid metabolism-related enzymes and their derivatives, such as glutamate decarboxylase and S-adenosylmethionine, all had high levels of accumulation in wild ginseng. The accumulation of sulfur amino acid synthesis-related proteins, such as methionine synthase, was also higher in wild ginseng. In addition, glycolysis and tricarboxylic acid cycle-related enzymes as well as their intermediates had high levels of accumulation in wild ginseng. CONCLUSION This study elucidates the differences in amino acids between wild and cultivated ginseng. These results will provide a reference for further studies on the medicinal functions of wild ginseng.