Glucosyltransferase activity in the serum samples.

<p>Rac1 glucosylation was assessed with serum from Case I on mRG1-1 cell (A) and Case II on Vero cells (B). mRG1-1 cells were co-cultured with serum (Case I) in the presence of A1H3 for 4hr at 37^°C. Vero cells were cultured with serum (Case II) alone for 4hr at same condition. Treated cells were lysed and non-glucosylated form Rac1 was detected by WB with specific anti-Rac1 (clone 102, BD Biosciences, San Diego, CA). Serum treatment led to glucosylation of Rac1, which was blocked by specific anti-TcdA or (and) TcdB antibody in Case I; and blocked by anti-TcdB not anti-TcdA in Case II. The data shown was a representative experiment from three independent experiments. The normalized data from 3 experiments (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0124235#sec002" target="_blank">Materials and Methods</a>) were presented in the lower panels. <i>P</i> value < 0.05 was considered as significance when compared to negative control (cell cultured in medium only). *, p< 0.05; **, <i>p</i>< 0.01