Force frequency curves of untreated C57, untreated mdx and taurine treated mdx EDL muscles.

<p>Isometric force produced at frequencies from 5–150 Hz was plotted for both specific force (A) and total force (B). Symbols for significant differences (p<0.05) are- * = between untreated mdx and C57, $ = between untreated mdx and taurine treated mdx and # between taurine treated mdx and C57. Data are presented as mean ± SEM and n = C57 (7), mdx (9) and taurine treated (7).</p

Fore limb grip strength of untreated C57, untreated mdx and taurine treated mdx mice.

<p>Data are presented as both force normalised to body weight (A) and total force (B). Symbols for significant differences (p<0.05) are- * = between untreated mdx and C57, $ = between untreated mdx and taurine treated mdx and # between taurine treated mdx and C57. Data are presented as mean ± SEM and n = C57 (9), mdx (10) and taurine treated (8).</p

Phenotypic data of untreated C57, untreated mdx and taurine treated mdx, including body and liver and quad and EDL weight (wt), tibia length and EDL cross sectional area (CSA).

<p>Phenotypic data of untreated C57, untreated mdx and taurine treated mdx, including body and liver and quad and EDL weight (wt), tibia length and EDL cross sectional area (CSA).</p

Beneficial effects of high dose taurine treatment in juvenile dystrophic mdx mice are offset by growth restriction - Fig 5

<p><b>Liver content (A) and activity (B) of cysteine dioxygenase, content of cysteine sulfinate (C) and cysteine sulfinate decarboxylase (D) in untreated C57, untreated mdx and taurine treated mdx mice.</b> CD = cysteine dioxygeasne, CS = cysteine sulfinate, CSD = cysteine sulfinate decarboxylase. Symbols for significant differences (p<0.05) are- * = between untreated mdx and C57, $ = between untreated mdx and taurine treated mdx and # between taurine treated mdx and C57. Data are presented as mean ± SEM and n = C57 (8), mdx (8) and taurine treated (8). Representative blots are shown, proteins were standardised to total protein using stain-free gels. From the same stain-free gel image, the loading of albumin is shown.</p

Le Courrier

30 septembre 18411841/09/30 (N273)

Limiting the Hydrolysis and Oxidation of Maleimide–Peptide Adducts Improves Detection of Protein Thiol Oxidation

Oxidative stress, caused by reactive oxygen and nitrogen species (RONS), is important in the pathophysiology of many diseases. A key target of RONS is the thiol group of protein cysteine residues. Because thiol oxidation can affect protein function, mechanistic information about how oxidative stress affects tissue function can be ascertained by identifying oxidized proteins. The probes used must be specific and sensitive, such as maleimides for the alkylation of reduced cysteine thiols. However, we find that maleimide-alkylated peptides (MAPs) are oxidized and hydrolyzed under sample preparation conditions common for proteomic studies. This can result in up to 90% of the MAP signal being converted to oxidized or hydrolyzed MAPs, decreasing the sensitivity of the analysis. A substantial portion of these modifications were accounted for by Coomassie “blue silver” staining (∼14%) of gels and proteolytic digestion buffers (∼20%). More than 40% of the MAP signal can be retained with the use of thioglycolic acid during gel electrophoresis, trichloroethanol–UV protein visualization in gels, and proteolytic digestion buffer of pH 7.0 TRIS. This work demonstrates that it is possible to decrease modifications to MAPs through changes to the sample preparation workflow, enhancing the potential usefulness of maleimide in identifying oxidized peptides