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

Shewanella putrefaciens is a microorganism with strong spoilage potential for aquatic products. This study aimed to investigate the potential spoilage factors of S. putrefaciens by comparative proteomic analysis. The spoilage potential of two strains of S. putrefaciens (00A and 00B) isolated from chilled spoiled bigeye tuna was investigated. The results of total volatile basic nitrogen (TVB-N), trimethylamine (TMA) in fish inoculated with S. putrefaciens, extracellular protease activity of S. putrefaciens, and degradation of fish proteins indicated that the spoilage potential of S. putrefaciens 00A was much higher than that of 00B. Fish proteins are usually degraded by spoilage microorganism proteases into small molecular peptides and amino acids, which are subsequently degraded into spoilage metabolites in bacterial cells, leading to deterioration of fish quality. Thus, proteomic analysis of the extracellular and intracellular proteins of 00A vs. 00B was performed. The results indicated that the intracellular differentially expressed protein (IDEP) contained 243 upregulated proteins and 308 downregulated proteins, while 78 upregulated proteins and 4 downregulated proteins were found in the extracellular differentially expressed protein (EDEP). GO annotation revealed that IDEP and EDEP were mainly involved in cellular and metabolic processes. KEGG annotation results showed that the upregulated proteins in IDEP were mainly involved in sulfur metabolism, amino acid metabolism, and aminoacyl-tRNA biosynthesis, while downregulated proteins were related to propanoate metabolism. In contrast, EDEP of KEGG annotation was mainly involved in ribosomes, quorum sensing, and carbohydrate metabolism. Proteins associated with spoilage containing sulfur metabolism (sulfite reductase, sulfate adenylyltransferase, adenylyl-sulfate kinase), amino acid metabolism (biosynthetic arginine decarboxylase, histidine ammonia-lyase), trimethylamine metabolism (trimethylamine-N-oxide reductase), and extracellular proteins (ATP-dependent Clp protease proteolytic subunit) were identified as upregulated. These proteins may play a key role in the spoilage potential of S. putrefaciens. These findings would contribute to the identification of key spoilage factors and understanding of the spoilage mechanism of microorganisms.

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Comparative Proteomic Analysis of Leaves at Different Ages in Allotriploid Populus

Forests ◽

10.3390/f11111154 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1154

Author(s):

Jiang Li ◽

Yi Wang ◽

Hairong Wei ◽

Xiangyang Kang

Keyword(s):

Amino Acid ◽

Carbon Metabolism ◽

Proteomic Analysis ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Leaf Age ◽

Enrichment Analysis ◽

C1 Metabolism ◽

Comparative Proteomic Analysis ◽

N Metabolism

Triploid poplar trees have been shown to have a number of growth advantages, especially much bigger leaves that contribute greatly to the increased biomass. In this study, we focused on the relationships between leaf age and leaf metabolism in triploids. We performed comparative proteomic analysis of the 5th (FDR5), 10th (FDR10), and 25th (FDR25) leaves from the apical meristems in allotriploids originated from first-division restitution (FDR). A total of 1970, 1916, and 1850 proteins were identified in the FDR5, FDR10, and FDR25, respectively. Principle component analysis (PCA) and differentially accumulated protein (DAP) analysis showed that FDR10 and FDR25 displayed higher similarities of protein accumulation patterns as compared to FDR5. MapMan enrichment analysis showed that several primary metabolic pathways or processes were significantly enriched in the DAPs. For example, photosynthesis, major CHO metabolism, glycolysis, N metabolism, redox, C1-metabolism, DNA, and protein turnover were significantly altered in both FDR10 and FDR25 compared with FDR5. In addition, amino acid metabolism and gluconeogenesis/glyoxylate cycle also underwent significant changes in FDR25 compared with FDR5. However, only amino acid metabolism was significantly enriched in the DAPs between FDR25 and FDR10. Further, DAP accumulation pattern analysis implied that FDR5, FDR10, and FDR25 were placed in the young, mature, and primary senescence stages of leaves. The most DAPs involved in the light reaction, photorespiration, Calvin cycle, starch and sucrose metabolism, pentose phosphate pathway (OPP), tricarboxylic acid (TCA) cycle, N metabolism, and C1-metabolism displayed higher accumulation in both FDR10 and FDR25 compared to FDR5. However, the most DAPs that are involved in cell wall and lipid metabolism, tetrapyrrole synthesis, nucleotide metabolism exhibited lower accumulation in both FDR10 and FDR25. Almost all DAPs between FDR-10 and FDR-25 showed a dramatic decrease in FDR25. KEGG enrichment analysis showed that carbon metabolism was altered significantly at different leaf ages. DAPs that are involved in carbon metabolism were predicted as different points in protein–protein interaction (PPI) networks from the STRING database. Finally, inconsistent transcript and protein abundance was found for DAPs, indicating the presence of posttranscriptional regulation during leaf-age progression process.

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