Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

Peptidoglycan (PG) is the major component of Gram positive bacteria cell wall and is essential for bacterial integrity and shape. Bacteria synthesize PG hydrolases (PGHs) which are able to cleave bonds in their own PG and play major roles in PG remodelling required for bacterial growth and division. Our aim was to identify the main PGHs in Lactobacillus casei BL23, a lactic acid bacterium with probiotic properties.The PGH complement was first identified in silico by amino acid sequence similarity searches of the BL23 genome sequence. Thirteen PGHs were detected with different predicted hydrolytic specificities. Transcription of the genes was confirmed by RT-PCR. A proteomic analysis combining the use of SDS-PAGE and LC-MS/MS revealed the main seven PGHs synthesized during growth of L. casei BL23. Among these PGHs, LCABL_02770 (renamed Lc-p75) was identified as the major one. This protein is the homolog of p75 (Msp1) major secreted protein of Lactobacillus rhamnosus GG, which was shown to promote survival and growth of intestinal epithelial cells. We identified its hydrolytic specificity on PG and showed that it is a γ-D-glutamyl-L-lysyl-endopeptidase. It has a marked specificity towards PG tetrapeptide chains versus tripeptide chains and for oligomers rather than monomers. Immunofluorescence experiments demonstrated that Lc-p75 localizes at cell septa in agreement with its role in daughter cell separation. It is also secreted under an active form as detected in zymogram. Comparison of the muropeptide profiles of wild type and Lc-p75-negative mutant revealed a decrease of the amount of disaccharide-dipeptide in the mutant PG in agreement with Lc-p75 activity. As a conclusion, Lc-p75 is the major L. casei BL23 PGH with endopeptidase specificity and a key role in daughter cell separation. Further studies will aim at investigating the role of Lc-p75 in the anti-inflammatory potential of L. casei BL23.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3288076PMC
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0032301PLOS

Publication Analysis

Top Keywords

casei bl23
16
lactobacillus casei
8
main pghs
8
role daughter
8
daughter cell
8
cell separation
8
major
6
casei
5
pghs
5
bl23
5

Similar Publications

Immune responses are highly complex and intricately regulated processes involving immune and non-immune cells in close direct and indirect contact with each other. These cells are highly sensitive to environmental signals, including factors derived from microbiota. Here, we demonstrate that the human microbiota member ()-derived cell-free supernatant (CFS) enhances the sensitivity of mesenchymal-stromal-cell-like (MSCI) cells to viral stimuli and induces the development of dendritic cells (DCs) with anti-inflammatory and antiviral properties via pretreated MSCl cells.

View Article and Find Full Text PDF

Enhanced antibody-defucosylation capability of α-L-fucosidase by proximity-based protein fusion.

Biochem Biophys Res Commun

February 2023

CAS Key Laboratory of Receptor Research, CAS Center for Excellence in Molecular Cell Science, Center for Biotherapeutics Discovery Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Pudong, Shanghai, 201203, PR China. Electronic address: tangfeng2013@si

Up to date, the reported fucosidases generally show poor activities toward the IgG core-fucose, which limits the efficiency of ENGase-catalyzed glycoengineering process. However, EndoS or EndoS2 owns excellent activity and great selectivity towards the N-glycosylation of IgGs, and their non-catalytic domains are deduced to have specific interactions to IgG Fc domain that result in the great activity and selectivity. Herein, we constructed a series fusion protein of AlfC (an α-l-fucosidase from Lactobacillus casei BL23) with EndoS/S2 non-catalytic domain by replacing the catalytic GH (glycan hydrolase) domain of EndoS/S2 with the AlfC.

View Article and Find Full Text PDF

Biofilms represent a major concern in the food industry and healthcare. The use of probiotic bacteria and their derivatives as an alternative to conventional treatments to fight biofilm development is a promising option that has provided convincing results in the last decades. Recently, membrane vesicles (MVs) produced by probiotics have generated considerable interest due to the diversity of roles they have been associated with.

View Article and Find Full Text PDF

The formation of membrane vesicles (MVs) by Gram-positive bacteria has gained increasing attention over the last decade. Recently, models of vesicle formation have been proposed and involve the digestion of the cell wall by prophage-encoded or stress-induced peptidoglycan (PG) hydrolases and the inhibition of PG synthesis by β-lactam antibiotics. The impact of these mechanisms on vesicle formation is largely dependent on the strain and growth conditions.

View Article and Find Full Text PDF