Proteomic analysis of Lactobacillus casei in response to different pHs using two-dimensional electrophoresis and MALDI TOF mass spectroscopy

Proteomic perspectives on thermotolerant microbes: an updated review

INTRODUCTION

Thermotolerant microbes are a group of microorganisms that survive in elevated temperatures. The thermotolerant microbes, which are found in geothermal heat zones, grow at temperatures of or above 45°C. The proteins present in such microbes are optimally active at these elevated temperatures. Hence, therefore, serves as an advantage in various biotechnological applications. In the last few years, scientists have tried to understand the molecular mechanisms behind the maintenance of the structural integrity of the cell and to study the stability of various thermotolerant proteins at extreme temperatures. Proteomic analysis is the solution for this search. Applying novel proteomic tools determines the proteins involved in the thermostability of microbes at elevated temperatures.

METHODS

Advanced proteomic techniques like Mass spectrometry, nano-LC-MS, protein microarray, ICAT, iTRAQ, and SILAC could enable the screening and identification of novel thermostable proteins.

RESULTS

This review provides up-to-date details on the protein signature of various thermotolerant microbes analyzed through advanced proteomic tools concerning relevant research articles. The protein complex composition from various thermotolerant microbes cultured at different temperatures, their structural arrangement, and functional efficiency of the protein was reviewed and reported.

CONCLUSION

This review provides an overview of thermotolerant microbes, their enzymes, and the proteomic tools implemented to characterize them. This article also reviewed a comprehensive view of the current proteomic approaches for protein profiling in thermotolerant microbes.

Identification of the effects of acid-resistant Lactobacillus casei metallopeptidase gene under colon-specific promoter on the colorectal and breast cancer cell lines

OBJECTIVES

Anti-tumor effects of Lactobacilli as normal flora have been described. In a previous study, we identified a protein isolated from the bacterium Lactobacillus casei ATCC 39392 in acidic pH conditions named metallopeptidase. Therefore, we decided to evaluate the effect of the recombinant plasmid coding metallopeptidase protein on the inhibition, proliferation, or apoptosis of the colorectal and breast cancer cell lines.

MATERIALS AND METHODS

Identified metallopeptidase gene of L. casei under the specific colon cancer promoter was transferred to the Human SW480 and MDA-MB231 cells. Cell viability was evaluated in these two cancer cell lines via MTT assay, apoptotic changes, and expression level of p53 and MAP2K1 genes in comparison with healthy blood cells as a control group.

RESULTS

Viability of SW480 and MDA-MB231 cells was identified at 25% and 7%, respectively. An increase in apoptotic cell death in the SW480 cell line was observed as revealed by Tunnel staining. The expression assay of TP53 and MAP2K1 genes showed that MPL protein altered gene expression in a cell type-specific manner. Tunnel analyses showed that the pronounced cytotoxic effect of pEGFP-C2/MPL plasmid on SW480 cells was mediated through apoptosis.

CONCLUSION

These results suggest that endogenous recombinant MPL under colon specific promoter inhibits the proliferation of SW480 colorectal cancer cells by increase in MAP2K1 and P53 activation. L. casei metallopeptidase under the same circumstances could not affect the growth rate and viability of MDA-MB231 breast cancer cells in vitro.