Label-free proteomic analysis revealed the mechanisms of protein oxidation induced by hydroxyl radicals in whiteleg shrimp (Litopenaeus vannamei) muscle

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

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Free amino acids mix made of poultry keratin improves survival of whiteleg shrimp post larvae (Litopenaeus vannamei) challenged with acute hepatopancreatic necrosis disease and white spot syndrome virus

Aquaculture International ◽

10.1007/s10499-021-00665-x ◽

2021 ◽

Vol 29 (2) ◽

pp. 879-890

Author(s):

Pierrick Kersanté ◽

Guillaume Le Reste ◽

Benoitr Diringer ◽

Juan Quimi ◽

Renaud Sergheraert ◽

...

Keyword(s):

Amino Acids ◽

Litopenaeus Vannamei ◽

Free Amino Acids ◽

Free Amino ◽

White Spot Syndrome Virus ◽

White Spot ◽

White Spot Syndrome ◽

Whiteleg Shrimp ◽

Acute Hepatopancreatic Necrosis Disease

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Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

Proteome Science ◽

10.1186/s12953-021-00172-0 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Huiyi Song ◽

Ni Lou ◽

Jianjun Liu ◽

Hong Xiang ◽

Dong Shang

Keyword(s):

Escherichia Coli ◽

Proteomic Analysis ◽

Biofilm Formation ◽

Lactobacillus Rhamnosus ◽

Differentially Expressed ◽

Differentially Expressed Proteins ◽

Label Free ◽

Quantitative Proteomic Analysis ◽

E Coli ◽

Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

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Complexes of Copper and Iron with Pyridoxamine, Ascorbic Acid, and a Model Amadori Compound: Exploring Pyridoxamine’s Secondary Antioxidant Activity

Antioxidants ◽

10.3390/antiox10020208 ◽

2021 ◽

Vol 10 (2) ◽

pp. 208

Author(s):

Guillermo García-Díez ◽

Roger Monreal-Corona ◽

Nelaine Mora-Diez

Keyword(s):

Antioxidant Activity ◽

Ascorbic Acid ◽

Rate Constant ◽

Stable Complex ◽

Aqueous Environment ◽

Oh Radicals ◽

Bidentate Ligands ◽

Superoxide Radical Anion ◽

Amadori Compound ◽

The Stability

The thermodynamic stability of 11 complexes of Cu(II) and 26 complexes of Fe(III) is studied, comprising the ligands pyridoxamine (PM), ascorbic acid (ASC), and a model Amadori compound (AMD). In addition, the secondary antioxidant activity of PM is analyzed when chelating both Cu(II) and Fe(III), relative to the rate constant of the first step of the Haber-Weiss cycle, in the presence of the superoxide radical anion (O2•−) or ascorbate (ASC−). Calculations are performed at the M05(SMD)/6-311+G(d,p) level of theory. The aqueous environment is modeled by making use of the SMD solvation method in all calculations. This level of theory accurately reproduces the experimental data available. When put in perspective with the stability of various complexes of aminoguanidine (AG) (which we have previously studied), the following stability trends can be found for the Cu(II) and Fe(III) complexes, respectively: ASC < AG < AMD < PM and AG < ASC < AMD < PM. The most stable complex of Cu(II) with PM (with two bidentate ligands) presents a ΔGf0 value of −35.8 kcal/mol, whereas the Fe(III) complex with the highest stability (with three bidentate ligands) possesses a ΔGf0 of −58.9 kcal/mol. These complexes can significantly reduce the rate constant of the first step of the Haber-Weiss cycle with both O2•− and ASC−. In the case of the copper-containing reaction, the rates are reduced up to 9.70 × 103 and 4.09 × 1013 times, respectively. With iron, the rates become 1.78 × 103 and 4.45 × 1015 times smaller, respectively. Thus, PM presents significant secondary antioxidant activity since it is able to inhibit the production of ·OH radicals. This work concludes a series of studies on secondary antioxidant activity and allows potentially new glycation inhibitors to be investigated and compared relative to both PM and AG.

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Label-free proteomic analysis of serum exosomes from paroxysmal atrial fibrillation patients

Clinical Proteomics ◽

10.1186/s12014-020-09304-8 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Hanwen Ni ◽

Wenqi Pan ◽

Qi Jin ◽

Yucai Xie ◽

Ning Zhang ◽

...

Keyword(s):

Atrial Fibrillation ◽

Protein Folding ◽

Protein Content ◽

Complement System ◽

Proteomic Analysis ◽

Surface Composition ◽

Label Free ◽

Healthy Donors ◽

Variable Surface ◽

Serum Exosomes

Abstract Background Atrial fibrillation (AF) is the most common cardiac heterogeneous rhythm disorder. It represents a major cause of mortality and morbidity, mainly related to embolic events and heart failure. Mechanisms of AF are complex and remain incompletely understood. Recent evidence suggests exosomes are membrane-coated objects released by many cell-types. Their presence in body fluids and the variable surface composition and content render them attractive as a mechanism for potential biomarkers. However, the content of serum exosomes of AF patients has not been fully delineated. Methods In this work, the serum exosomes from AF patients and healthy donors were used to compare changes in the exosome protein content. Exosomes were isolated from serum of AF patients and healthy donors and their purity was confirmed by Western blotting assays and transmission electron microscopy (TEM). Label-free LC–MS/MS quantitative proteomic analysis was applied to analyze protein content of serum exosomes. Results A total of 440 exosomal protein groups were identified, differentially expressed proteins were filtrated with fold change ≥ 2.0 (AF/controls protein abundance ratio ≥ 2 or ≤ 0.5) and p value less than 0.05 (p < 0.05), significantly changed in abundance group contains 39 elevated proteins and 18 reduced proteins, while consistent presence/absence expression profile group contains 40 elevated proteins and 75 reduced proteins. Bioinformatic analysis of differential exosomal proteins confirmed the significant enrichment of components involved in the anticoagulation, complement system and protein folding. Parallel-Reaction Monitoring Relative Quantitative Analysis (PRM) further suggested that AF related to complement system and protein folding. Conclusions These results revealed the composition and potential function of AF serum exosomes, thus providing a new perspective on the complement system and protein folding to AF.

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