sakei strain MF1053 grown on glucose (c). Protein (50 μg) was loaded, and 2-DE was performed using a pH range of 4-7 in the first dimension and SDS-PAGE (12.5%) in the second dimension. Protein size (kDa) is shown on the right side of each gel image. Spots listed in Additional files 1 and 2, Tables S2 and S3 are indicated. The black rectangle (a) shows the region of the GapA isoforms which differ among the strains. Comparison of protein patterns obtained from cells grown on glucose or ribose revealed, for all the strains, differences in the expression profiles. The spots presenting a volume change depending on the carbon source used
for growth and identified by MALDI-TOF MS are shown in Figure 1ab in representative https://www.selleckchem.com/products/incb28060.html 2-DE gel images. All the buy LY2874455 proteins could be identified against L. sakei 23K proteins, as shown in Additional file 1, Table S2. Data obtained for a few P505-15 concentration spots gave less statistically significant results (q = 0.05-0.1) due to co-migration of proteins which made quantification measurements unreliable. However, visual inspection of these protein spots in the 2-DE gels confirmed a modification in their volume. Nine proteins displayed a different level of expression in all tested strains, whereas 11 proteins varied in at least one of the strains (Additional file 1). Moreover, when compared to the other strains we observed that L. sakei
MF1053 over-expressed a set of seven proteins after growth on both carbon sources, as shown in Additional file 2, Table S3. The proteins could be identified against L. sakei 23K proteins, except for two proteins which identified against proteins from other L. sakei strains and were similar to proteins from Lactobacillus plantarum and Lactobacillus buchneri (Additional file 2). The presence of several isoforms with
different pIs was also noticed for several proteins (Additional files 1 and 2). Many proteins are modified after synthesis by different types of posttranslational modifications (PTM) which may control the protein activity, and the most common PTM accounted for pI differences is phosphorylation . Proteins differentially expressed between growth on glucose and ribose In total, ten proteins were up-regulated in all or Nintedanib (BIBF 1120) most of the strains after growth on ribose. Among those, three are directly involved in ribose catabolism: RbsD, the D-ribose pyranase, RbsK, the ribokinase, and Xpk, the putative phosphoketolase. This is in accordance with finding by Stentz et al.  who observed the induction of the rbsUDKR operon transcription and an increase of phosphoketolase and ribokinase activity after growth on ribose. The two pyruvate oxidases and two of the four components of the pyruvate dehydrogenase complex (PDC) were also detected as up-regulated in ribose grow cells.