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The objective of this study was the characterization of the surface layer proteins (SLPs) and their functional role in the probiotic activity of Lactobacillus helveticus fb213, L. acidophilus fb116 and L. acidophilus fb214. SLPs were extracted and identified by SDS-PAGE, circular dichroism spectra and LC-MS analysis. The results revealed that the molecular masses of the three proteins were 49.7 kDa, 46.0 kDa and 44.6 kDa, respectively. The secondary structures and amino acid compositions of the three proteins were found to be similar. After removing SLPs, the survival of the three lactobacilli in simulated gastric and intestinal juices was reduced by 2-3log as compared with survival of the intact cells. And the adhesion ability of the three strains to HT-29 cells decreased by 61%, 65% and 92%, respectively. SLPs also inhibited the adhesion and invasion of Escherichia coli ATCC 43893 to HT-29 cells. These results suggest that SLPs are advantageous barriers for lactobacilli in the gastrointestinal tract, and these proteins help make it possible for lactobacilli to serve their probiotic functions.
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http://dx.doi.org/10.1016/j.ijbiomac.2014.01.024 | DOI Listing |
Chem Biodivers
September 2025
Zhejiang Provincial Key Laboratory of Agricultural Microbiomics, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, P. R. China.
A novel and efficient hydrogen peroxide/ascorbic acid-assisted extraction method for the preparation of Grifola frondosa polysaccharide (GFP) was developed, and two GFP fractions (GFP-H and GFP-L) with different molecular weights (Mws) were obtained by separation with ultrafiltration. Both high Mw component (GFP-H, Mw 396.4 kDa) and low Mw component (GFP-L, Mw 12.
View Article and Find Full Text PDFChem Biodivers
September 2025
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
This research emphasized the extraction and separation of polysaccharides derived from Syzygium jambos (L.) Alston (PSJAP-5), as well as analyses of their structural characteristics and immunomodulatory activities. This study initially employed response surface methodology to determine the extraction conditions of polysaccharides.
View Article and Find Full Text PDFPLoS Biol
September 2025
Department of Systems Immunology, Weizmann Institute of Science, Rehovot, Israel.
Multiple sclerosis (MS) is a chronic neurological disorder characterized by demyelination of the central nervous system (CNS), leading to a broad spectrum of physical and cognitive impairments. Myeloid cells within the CNS, including microglia and border-associated macrophages, play a central role in the neuroinflammatory processes associated with MS. Activation of these cells contributes to the local inflammatory response and promotes the recruitment of additional immune cells into the CNS.
View Article and Find Full Text PDFJ Vis Exp
August 2025
Laser Biomedical Research Center, G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology.
We present multimodal confocal Raman micro-spectroscopy (RS) and tomographic phase microscopy (TPM) for quick morpho-chemical phenotyping of human breast cancer cells (MDA-MB-231). Leveraging the non-perturbative nature of these advanced microscopy techniques, we captured detailed morpho-molecular data from living, label-free cells in their native physiological environment. Human bias-free data processing pipelines were developed to analyze hyperspectral Raman images (spanning Raman modes from 600 cm to 1800 cm, which uniquely characterize a wide range of molecular bonds and subcellular structures), as well as morphological data from three-dimensional refractive index tomograms (providing measurements of cell volume, surface area, footprint, and sphericity at nanometer resolution, alongside dry mass and density).
View Article and Find Full Text PDFMacromol Biosci
September 2025
Department of Pharmaceutical Technology, Faculty of Pharmacy, Ankara University, Tandogan, Ankara, Turkey.
The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has highlighted the critical need for safe and effective vaccines. In this study, subunit nanovaccine formulations were developed using the receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein encapsulated in polymeric nanoparticles composed of poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-PCL). Two surfactants, poly(vinyl alcohol) (PVA) and sodium cholate (SC), were evaluated during formulation via a modified water-in-oil-in-water (w/o/w) emulsion-solvent evaporation method.
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