Protective function of surface layer protein from Lactobacillus casei fb05 against intestinal pathogens in vitro

2021 ◽  
Vol 546 ◽  
pp. 15-20
Author(s):  
Jun Meng ◽  
Yan-Yang Wang ◽  
Yun-Peng Hao
Keyword(s):  
Surface Layer ◽  
Lactobacillus Casei ◽  
Protective Function ◽  
Surface Layer Protein ◽  
Intestinal Pathogens

scholarly journals A Bacterial Surface Layer Protein Exploits Multi-step Crystallization for Rapid Self-assembly

2019 ◽  
Author(s):  
Jonathan Herrmann ◽  
Po-Nan Li ◽  
Fatemeh Jabbarpour ◽  
Anson C. K. Chan ◽  
Ivan Rajkovic ◽  
...  
Keyword(s):  
Surface Layer ◽  
Self Assembly ◽  
Molecular Mechanisms ◽  
Protein Crystallization ◽  
Crystal Nucleation ◽  
Time Resolved ◽  
Bacterial Surface ◽  
Surface Layer Protein

AbstractSurface layers (S-layers) are crystalline protein coats surrounding microbial cells. S-layer proteins (SLPs) regulate their extracellular self-assembly by crystallizing when exposed to an environmental trigger. However, molecular mechanisms governing rapid protein crystallization in vivo or in vitro are largely unknown. Here, we demonstrate that the C. crescentus SLP readily crystallizes into sheets in vitro via a calcium-triggered multi-step assembly pathway. This pathway involves two domains serving distinct functions in assembly. The C-terminal crystallization domain forms the physiological 2D crystal lattice, but full-length protein crystallizes multiple orders of magnitude faster due to the N-terminal nucleation domain. Observing crystallization using time-resolved electron cryo-microscopy (Cryo-EM) reveals a crystalline intermediate wherein N-terminal nucleation domains exhibit motional dynamics with respect to rigid lattice-forming crystallization domains. Dynamic flexibility between the two domains rationalizes efficient S-layer crystal nucleation on the curved cellular surface. Rate enhancement of protein crystallization by a discrete nucleation domain may enable engineering of kinetically controllable self-assembling 2D macromolecular nanomaterials.Significance StatementMany microbes assemble a crystalline protein layer on their outer surface as an additional barrier and communication platform between the cell and its environment. Surface layer proteins efficiently crystallize to continuously coat the cell and this trait has been utilized to design functional macromolecular nanomaterials. Here, we report that rapid crystallization of a bacterial surface layer protein occurs through a multi-step pathway involving a crystalline intermediate. Upon calcium-binding, sequential changes occur in the structure and arrangement of the protein, which are captured by time-resolved small angle x-ray scattering and transmission electron cryo-microscopy. We demonstrate that a specific domain is responsible for enhancing the rate of self-assembly, unveiling possible evolutionary mechanisms to enhance the kinetics of 2D protein crystallization in vivo.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

scholarly journals Active immunization of hamsters againstClostridium difficileinfection using surface-layer protein

2008 ◽  
Vol 52 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Déirdre B. Ní Eidhin ◽  
Julie B. O'Brien ◽  
Matthew S. McCabe ◽  
Verónica Athié-Morales ◽  
Dermot P. Kelleher
Keyword(s):  
Surface Layer ◽  
Active Immunization ◽  
Surface Layer Protein

Investigation of in-vitro bacterial surface layer formation by FBARs

2009 ◽  
Author(s):  
Michael Mertig ◽  
Anja Bluher ◽  
Christiane Erler ◽  
Beate Katzschner ◽  
Wolfgang Pompe ◽  
...  
Keyword(s):  
Surface Layer ◽  
Layer Formation ◽  
Bacterial Surface ◽  
Surface Layer Formation

scholarly journals Endothelial Cells Require STAT3 for Protection against Endotoxin-induced Inf lammation

2003 ◽  
Vol 198 (10) ◽  
pp. 1517-1525 ◽  
Author(s):  
Arihiro Kano ◽  
Michael J. Wolfgang ◽  
Qian Gao ◽  
Joerg Jacoby ◽  
Gui-Xuan Chai ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transforming Growth Factor ◽  
Endotoxic Shock ◽  
Transforming Growth Factor Β ◽  
Organ Damage ◽  
Interleukin 10 ◽  
Interferon Γ ◽  
Protective Function ◽  
Lps Challenge

Endothelial cells (ECs) are believed to be an important component in the protection from lipopolysaccharide (LPS)-induced endotoxic shock. However, the cellular and molecular mechanism is not well defined. Here, we report that signal transducer and activator of transcription (STAT) 3 is an essential regulator of the antiinflammatory function of ECs in systemic immunity. Because STAT3 deficiency results in early embryonic lethality, we have generated mice with a conditional STAT3 deletion in endothelium (STAT3E−/−). STAT3E−/− mice are healthy and fertile, and isolated ECs initiate normal tube formation in vitro. Conditional endothelial but not organ-specific (i.e., hepatocyte or cardiomyocyte) STAT3 knockout mice show an increased susceptibility to lethality after LPS challenge. The LPS response in STAT3E−/− mice shows exaggerated inflammation and leukocyte infiltration in multiple organs combined with elevated activity of serum alanine aminotransferase and aspartate aminotransferase, indicating organ damage. Concomitantly, proinflammatory cytokines are produced at an exaggerated level and for a prolonged period. This defect cannot be explained by lack of antiinflammatory cytokines, such as interleukin 10 and transforming growth factor β. Instead, we have shown that a soluble activity derived from endothelia and dependent on STAT3 is critical for suppression of interferon γ. These data define STAT3 signaling within endothelia as a critical antiinflammatory mediator and provide new insight to the protective function of ECs in inflammation.

scholarly journals A Computational Approach for Protein-Protein Interactions of Bacterial Surface Layer Protein with Human Erb3 and αIIB-β3 Receptors

2021 ◽  
Vol 12 (1) ◽  
pp. 420-430
Keyword(s):  
Surface Layer ◽  
Molecular Docking ◽  
Protein Interactions ◽  
Protein A ◽  
Computational Approach ◽  
Microbial Interactions ◽  
Protein Protein Interactions ◽  
Epithelial Surface ◽  
Surface Receptors ◽  
Surface Layer Protein

Host microbial interactions had significant factors in maintains homeostasis and immune-related activity. One such interaction made by Lactobacillus sp. with Surface layer proteins (Slps) had been studied through a computational approach. Erb3 and αIIB-β3, which are epithelial surface layer receptors, are subjected to interact with the Slp homology model. Both cell surface receptors were subjected to interact through computational docking, followed by molecular dynamics simulations through the coarse-grain method to explore the conformational stability. Through the implementation of the molecular docking for the surface layer protein A, we have shown the surface layer protein A, protein-protein interactions are higher in cellular receptors with epidermal growth factor receptor at an -34.45 ΔG and -51.19 ΔG through molecular docking with Erb3 and αIIB-β3. This study shows the unique interaction of Slp with the epithelial surface receptors like Erb3 and αIIB-β3, which are multipurpose applications in microbial-based drug therapeutics.

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