Outermost Component Research Articles

Molecular mechanism of lipopolysaccharide (LPS) in promoting biomineralization on bacterial surface

Biomineralization on bacterial surface is affected by biomolecules of bacterial cell surface. Lipopolysaccharide (LPS) is the main and outermost component on the extracellular membrane of Gram-negative bacteria. In the present study, the molecular mechanism of LPS in affecting biomineralization of Ag+/Cl− colloids was investigated by taking advantages of two LPS structural deficient mutants of Escherichia coli. The two mutants were generated by impairing the expression of waaP or wbbH genes with CRISPR/Cas9 technology and it induced deficient polysaccharide chain of O-antigen (ΔwbbH) or phosphate groups of core oligosaccharide (ΔwaaP) in LPS structures. There were significant changes of the cell morphology and surface charge of the two mutants in comparing with that of wild type cells. LPS from ΔwaaP mutant showed increased ΔHITC upon interacting with free Ag+ ions than LPS from wild type cells or ΔwbbH mutant, implying the binding affinity of LPS to Ag+ ions is affected by the phosphate groups in core oligosaccharide. LPS from ΔwbbH mutant showed decreased endotherm (ΔQ) upon interacting with Ag+/Cl− colloids than LPS from wild type or ΔwaaP mutant cells, implying LPS polysaccharide chain structure is critical for stabilizing Ag+/Cl− colloids. Biomineralization of Ag+/Cl− colloids on ΔwbbH mutant cell surface showed distinctive morphology in comparison with that of wild type or ΔwaaP mutant cells, which confirmed the critical role of O-antigen of LPS in biomineralization. The present work provided molecular evidence of the relationship between LPS structure, ions, and ionic colloids in biomineralization on bacterial cell surface.

Isolation and Characterization of Cell Envelope Fragments Comprising Archaeal S-Layer Proteins.

The outermost component of cell envelopes of most bacteria and almost all archaea comprise a protein lattice, which is termed Surface (S-)layer. The S-layer lattice constitutes a highly porous structure with regularly arranged pores in the nm-range. Some archaea thrive in extreme milieus, thus producing highly stable S-layer protein lattices that aid in protecting the organisms. In the present study, fragments of the cell envelope from the hyperthermophilic acidophilic archaeon Saccharolobus solfataricus P2 (SSO) have been isolated by two different methods and characterized. The organization of the fragments and the molecular sieving properties have been elucidated by transmission electron microscopy and by determining the retention efficiency of proteins varying in size, respectively. The porosity of the archaeal S-layer fragments was determined to be 45%. S-layer fragments of SSO showed a retention efficiency of up to 100% for proteins having a molecular mass of ≥ 66 kDa. Moreover, the extraction costs for SSO fragments have been reduced by more than 80% compared to conventional methods, which makes the use of these archaeal S-layer material economically attractive.

Structural Variability of Lipoarabinomannan Modulates Innate Immune Responses within Infected Alveolar Epithelial Cells.

Mycobacterium tuberculosis (M. tb) is an intracellular pathogen persisting in phagosomes that has the ability to escape host immune surveillance causing tuberculosis (TB). Lipoarabinomannan (LAM), as a glycolipid, is one of the complex outermost components of the mycobacterial cell envelope and plays a critical role in modulating host responses during M. tb infection. Different species within the Mycobacterium genus exhibit distinct LAM structures and elicit diverse innate immune responses. However, little is known about the mechanisms. In this study, we first constructed a LAM-truncated mutant with fewer arabinofuranose (Araf) residues named M. sm-ΔM_6387 (Mycobacterium smegmatis arabinosyltransferase EmbC gene knockout strain). It exhibited some prominent cell wall defects, including tardiness of mycobacterial migration, loss of acid-fast staining, and increased cell wall permeability. Within alveolar epithelial cells (A549) infected by M. sm-ΔM_6387, the uptake rate was lower, phagosomes with bacterial degradation appeared, and microtubule-associated protein light chain 3 (LC3) recruitment was enhanced compared to wild type Mycobacterium smegmatis (M. smegmatis). We further confirmed that the variability in the removal capability of M. sm-ΔM_6387 resulted from host cell responses rather than the changes in the mycobacterial cell envelope. Moreover, we found that M. sm-ΔM_6387 or its glycolipid extracts significantly induced expression changes in some genes related to innate immune responses, including Toll-like receptor 2 (TLR2), class A scavenger receptor (SR-A), Rubicon, LC3, tumor necrosis factor alpha (TNF-α), Bcl-2, and Bax. Therefore, our studies suggest that nonpathogenic M. smegmatis can deposit LC3 on phagosomal membranes, and the decrease in the quantity of Araf residues for LAM molecules not only impacts mycobacterial cell wall integrity but also enhances host defense responses against the intracellular pathogens and decreases phagocytosis of host cells.

Structural Determination and Genetic Identification of the O-Antigen from an Escherichia coli Strain, LL004, Representing a Novel Serogroup.

The O-antigen is the outermost component of the lipopolysaccharide layer in Gram-negative bacteria, and the variation of O-antigen structure provides the basis for bacterial serological diversity. Here, we determined the O-antigen structure of an Escherichia coli strain, LL004, which is totally different from all of the E. coli serogroups. The tetrasaccharide repeating unit was determined as →4)-β-d-Galp-(1→3)-β-d-GlcpNAc6OAc(~70%)-(1→3)-β-d-GalpA-(1→3)-β-d-GalpNAc-(1→ with monosaccharide analysis and NMR spectra. We also characterized the O-antigen gene cluster of LL004, and sequence analysis showed that it correlated well with the O-antigen structure. Deletion and complementation testing further confirmed its role in O-antigen biosynthesis, and indicated that the O-antigen of LL004 is assembled via the Wzx/Wzy dependent pathway. Our findings, in combination, suggest that LL004 should represent a novel serogroup of E. coli.

High-resolution mapping of metal ions reveals principles of surface layer assembly in Caulobacter crescentus cells

SummarySurface layers (S-layers) are proteinaceous crystalline coats that constitute the outermost component of most prokaryotic cell envelopes. In this study, we have investigated the role of metal ions in the formation of the Caulobacter crescentus S-layer using high-resolution structural and cell biology techniques, as well as molecular simulations. Utilizing optical microscopy of fluorescently tagged S-layers, we show that calcium ions facilitate S-layer lattice formation and cell-surface binding. We report all-atom molecular dynamics simulations of the S-layer lattice, revealing the importance of bound metal ions. Finally, using electron cryomicroscopy and long-wavelength X-ray diffraction experiments, we mapped the positions of metal ions in the S-layer at near-atomic resolution, supporting our insights from the cellular and simulations data. Our findings contribute to the understanding of how C. crescentus cells form a regularly arranged S-layer on their surface, with implications on fundamental S-layer biology and the synthetic biology of self-assembling biomaterials.

SARS CoV-2 SPIKE GLYCOPROTEIN MUTATIONS AND CHANGES IN PROTEIN STRUCTURE

Severe Acute Respiratory Syndrome Corona Virus-2 (SARS CoV-2) is a single-stranded positive polarity RNA virus with a high virulence effect. Spike (S) glycoprotein is the outermost component of the SARS CoV-2 virion and is important in the entry of the virus into the cell via the angiotensin converting enzyme 2 (ACE2) receptor. ACE2 plays an important role in the regulation of human blood pressure by converting the vasoconstrictor angiotensin 2 to the vasodilator angiotensin 1-7. In this study, the changes that mutations in Asian isolates may cause in S glycoprotein structure were analyzed and modeled to contribute to drug and vaccine targeting studies. Genome, proteome and mutation analyses were done using bioinformatics tools (MAFFT, MegaX, PSIPRED, MolProbity, PyMoL). Protein modelling was performed using ProMod3. We detected 26 mutations in the S glycoprotein. The changes that these mutations reveal in the general topological and conformational structure of the S glycoprotein may affect the virulence features of SARS CoV-2. It was determined that mutations converted the receptor binding domain (RBD) from down-formation to like-up formation. It is thought that conformational change occurring after mutation in RBD may cause an increase in receptor affinity. These findings could be beneficial for disease prevention of and drug/vaccine development for SARS CoV-2.

Long‐Range Chiral Induction by a Fully Noncovalent Approach in Supramolecular Porphyrin–Calixarene Assemblies

The hierarchical assembly, in aqueous solution, of a new multi-metalloporphyrin/calixarene aggregate has been accomplished. In this supramolecular system transfer of chirality, from the outermost components to the central porphyrin reporter, takes place as a result of favorable and fully noncovalent long-range electronic communication.

S-layer protein modulates the stimulatory effects of Lactobacillus acidophilus CICC 6074 by triggering PKC signaling cascade in RAW 264.7 cells

Lactic acid bacteria (LAB) are demonstrably beneficial on the digestive and immune systems. S-layer protein (SlpA), as the outermost component of the cell wall, exerts an anti-inflammatory activity in lactobacilli, while the pro-inflammatory properties of SlpA in cross-talk with immune cells have rarely been investigated. Here, we showed that SlpA isolated from Lactobacillus acidophilus CICC 6074 exhibits more pronounced pro-inflammatory behavior through activating MAPK and NF-κB signaling, which was further corroborated by an increase in the NF-κB translocation from cytoplasm to the nucleus and DNA binding activity of NF-κB, triggered by SlpA treatment. Notably, a specific PKC inhibitor, chelerythrine, significantly blocked SlpA-elicited pro-inflammatory response, indicating that SlpA could act as stimulators of the innate immune system by triggering PKC to MAPK and NF-κB signaling pathway. This study provides important insights on the immunomodulatory properties of cell surface components in lactobacilli.

Sensor Design Migration: The Case of a VRG

Vibrating ring gyroscopes (VRG) have been shown to achieve a high scale-factor with low non-linearity while some structural modification can help increase their shock resistance in space applications. With some tuning, their quadrature error can be nearly eliminated, thus, minimizing device sensitivity to external factors while keeping a good alignment between the drive and sense-mode frequencies. VRG design is optimized for high scale-factor, low non-linearity, and high shock-resistance while satisfying process related constraints. When the device wafer is processed independent of the capping wafers, the process imposes topology constraints on the device trenches and forces anchors and other stator features to be on the outside of the device. In this paper, we have shown how a VRG that has been designed with a radially outwards topology, having its anchor in the center as the innermost component, can be reconfigured into a VRG with a radially inwards topology with its anchors at the rim as the outermost component. This design transformation can be construed as a VRG design migration from a three-wafer process to a single-wafer process. The process-driven reconfiguration comes at the cost of a lower scale-factor but with no impact on the operating range of the original design. The paper further proposes the use of directional masses to achieve better inertial modal control of the VRG. The resulting radially inwards VRG has been fabricated in the standard SOIMUMPS process, and preliminary experimental results have shown the functionality of the device under atmospheric pressure.

Genetic Determinants of Virulence between Two Foot-and-Mouth Disease Virus Isolates Which Caused Outbreaks of Differing Severity.

Individual foot-and-mouth disease virus (FMDV) strains reveal different degrees of infectivity and pathogenicity in host animals. The differences in severity among outbreaks might be ascribable to these differences in infectivity among FMDV strains. To investigate the molecular mechanisms underlying these differences, we estimated the infectivity of O/JPN/2000 and O/JPN/2010, which caused outbreaks of markedly different scales, in cell lines, Holstein cattle, and suckling mice. Viral growth of the two strains in cells was not remarkably different; however, O/JPN/2000 showed apparently low transmissibility in cattle. Mortality rates of suckling mice inoculated intraperitoneally with a 50% tissue culture infective dose (TCID50) of 10 for O/JPN/2000 and O/JPN/2010 also differed, at 0% and 100%, respectively. To identify genes responsible for this difference in infectivity, genetic regions of the full-length cDNA of O/JPN/2010 were replaced with corresponding fragments of O/JPN/2000. A total of eight recombinant viruses were successfully recovered, and suckling mice were intraperitoneally inoculated. Strikingly, recombinants having either VP1 or 3D derived from O/JPN/2000 showed 0% mortality in suckling mice, whereas other recombinants showed 100% mortality. This finding indicates that VP1, the outermost component of the virus particle, and 3D, an RNA-dependent RNA polymerase, are individually involved in the virulence of O/JPN/2010. Three-dimensional structural analysis of VP1 confirmed that amino acid differences between the two strains were located mainly at the domain interacting with the cellular receptor. On the other hand, measurement of their mutation frequencies demonstrated that O/JPN/2000 had higher replication fidelity than O/JPN/2010.IMPORTANCE Efforts to understand the universal mechanism of foot-and-mouth disease virus (FMDV) infection may be aided by knowledge of the molecular mechanisms which underlie differences in virulence beyond multiple topotypes and serotypes of FMDV. Here, we demonstrated independent genetic determinants of two FMDV isolates which have different transmissibility in cattle, namely, VP1 and 3D protein. Findings suggested that the selectivity of VP1 for host cell receptors and replication fidelity during replication were important individual factors in the induction of differences in virulence in the host as well as in the severity of outbreaks in the field. These findings will aid the development of safe live vaccines and antivirals which obstruct viral infection in natural hosts.

Intranasal curcumin protects against LPS-induced airway remodeling by modulating toll-like receptor-4 (TLR-4) and matrixmetalloproteinase-9 (MMP-9) expression via affecting MAP kinases in mouse model.

Bacterial infections can exacerbate asthmatic inflammation depending on lipopolysaccharide (LPS) composition, the outermost component of cell wall, its exposure timings as well as host's immune status. In present study, Balb/c mice were exposed to antigen (ovalbumin) and LPS simultaneously to establish an asthmatic model. Curcumin (diferuloylmethane), well known for its anti-inflammatory potential, was administered through intranasal route 1h before LPS and OVA (ovalbumin) exposure to evaluate its efficacy against airway structural changes. Inflammatory cell infiltration in lungs was measured by flow cytometry and further eosinophils were especially measured by immunofluorescence detection of major basic protein (MBP) as marker of eosinophilc granule protein. We also measured reactive oxygen species (ROS) in BALF by spectrofluorometry. MMP-9 activity was evaluated by gelatin zymography and mRNA expressions of MMP-9, TIMP-1, TGF-β1, IL-13, Collagen-1 and TLR-4 were measured in lungs. Protein expression of MAP kinases (P-ERK, P-JNK, P-p38), TLR-4, Cox-2, Lox-5 and Eotaxin was measured by western blotting. Hydroxyproline level and masson's trichrome staining were used to evaluate collagen deposition in lung. Exposure to LPS (0.1µg) exacerbates airway inflammation and induces structural changes in lungs by enhanced ROS production, collagen deposition, expression of genes involved in airway remodeling and activation of MAP kinases pathway enzymes. Intranasal curcumin pretreatment had significantly suppressed inflammatory mediators and airway remodeling proteins. Our results strongly suggest that intranasal curcumin effectively protects LPS-induced airway inflammation and structural changes by modulating genes involved in airway remodeling in safer way; hence, it can be considered as supplementary alternative towards asthma treatments.

Targeting Outer Membrane Protein Component AdeC for the Discovery of Efflux Pump Inhibitor against AdeABC Efflux Pump of Multidrug Resistant Acinetobacter baumannii.

The structure and functioning of multidrug efflux systems provide us with a better understanding of the transport of various antibiotics, thus giving a path for the discovery of effective compounds for combating the multidrug resistance in Acinetobacter baumannii. In the present study, a number of computational techniques have been used to search for an inhibitor for the RND efflux pump, AdeABC, of A. baumannii targeting specifically its outermost component, i.e., AdeC. We have prepared the three-dimensional structure for AdeC using MODELLER v9.16 and identified its active binding site using SiteMap. Using high-throughput virtual screening, we identified compounds from a large library of biogenic compounds on the basis of their effective interaction at the binding site of AdeC. The validation of docking step was performed by plotting ROC curve (enrichment calculations). The docked complexes were further analyzed for their binding free energies by molecular mechanics using Generalized Born model and Solvent Accessibility (MMGBSA). The molecular dynamics simulation was performed for AdeC-ZINC77257599 complex using GROMACS. The present rational drug designing, molecular mechanics and molecular dynamics data provided an inhibitor, i.e, ZINC77257599 [(3R,4Z,6E,8E)-3-hydroxy-2,2,4-trimethyl-10-oxazol-5-yl-deca-4,6,8-trienamide], for the outer membrane protein component (AdeC) of efflux pump AdeABC of A. baumannii.

Characterization of a Putative S-layer Protein of a Colonial Microcystis Strain.

Cell surface structure plays a key role in Microcystis colony formation. The S-layer is a crystalline array of monomolecular proteins that constitute the outermost component of the cyanobacterial cell envelope. To date, no biochemical characterization of the S-layer protein in Microcystis has been reported. Here, we compared S-layer on the cell wall of the unicellular strain Microcystis aeruginosa PCC7806 with the colonial strain M. aeruginosa XW01. We observed crystalline S-layers in XW01 cell walls; however, similar structures were not observed in PCC7806. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed a thick putative S-layer protein band with an apparent molecular weight of 70kDa extracted from XW01 cells, as well as an S-layer peptide fragment with the sequence ETYPLLAAPGAATDATR, similar to the translated product from PCC7806 unknown gene CAO89090.1. The amino acid composition of the translated CAO89090.1 product shared biochemical characteristics with those of bacterial S-layer proteins. Furthermore, a 1002-bp DNA fragment amplified from XW01 displayed 95% similarity with the CAO89090.1 gene, while the S-layer gene expression in XW01 was 36-fold higher than that observed in PCC7806. These data suggested that the S-layer protein plays a key role in Microcystis colony formation due to its significant contribution to cell surface hydrophobicity.

Self-Assembling 2D Nano-Crystalline of Recombinant Surface Layer Proteins (S-Layer) on Solid Substrates and Electrical Responses

ABSTRACTS-layer proteins of various lattice-forming types are the most abundant protein by mass on earth. They form the outermost cell crystalline component in a broad range of bacteria and archaea. They are porous monomolecular layer with unit cell size in tens of nanometers. These monomer proteins are capable of forming self-assembled mono- or double layers. Isolated from cell surfaces or through recombinant protein production, they are able to form ordered 2D crystal lattice on a variety of non-cellular surfaces. We study S-layer SbpA protein, which is found in mesophilic organism Lysinibacillus sphaericus with square lattice crystallinity. The recombinant SbpA (rSbpA) can be genetically modified and expressed in E. coli in different truncated forms. Using both the wtSpbA and truncated rSbpA, we reproduced the unique two-dimensional self-assembly pattern on several solid or flexible surfaces of interests towards electronic devices. By surface modification we can promote the self-assembly of SbpA on low affinity substrates. This enables a potential mean of creating complex functional bio-nanostructure. Delicate control of the self-assembly processes of S-layer on surfaces also serves the prerequisite of building the supramolecular structure as bio-electronic platform through protein fusing. Understanding of the electrical response from s-layer proteins provides a bridge between biological systems and electronic devices. Scale-up production and understanding the detailed interaction of the S-layer interface will likely be useful for nanobiotechnology and synthetic biology.

Probiotic Properties of Lactobacillus crispatus 2,029: Homeostatic Interaction with Cervicovaginal Epithelial Cells and Antagonistic Activity to Genitourinary Pathogens.

Lactobacillus crispatus 2029 isolated upon investigation of vaginal lactobacilli of healthy women of reproductive age was selected as a probiotic candidate. The aim of the present study was elucidation of the role of L. crispatus 2029 in resistance of the female reproductive tract to genitourinary pathogens using cervicovaginal epithelial model. Lactobacillus crispatus 2029 has surface layers (S-layers), which completely surround cells as the outermost component of their envelope. S-layers are responsible for the adhesion of lactobacilli on the surface of cervicovaginal epithelial cells. Study of interactions between L. crispatus 2029 and a type IV collagen, a major molecular component of epithelial cell extracellular matrix, showed that 125I-labeled type IV collagen binds to lactobacilli with high affinity (Kd = (8.0 ± 0.7) × 10(-10) M). Lactobacillus crispatus 2029 consistently colonized epithelial cells. There were no toxicity, epithelial damage and apoptosis after 24 h of colonization. Electronic microscope images demonstrated intimate association between L. crispatus 2029 and epithelial cells. Upon binding to epithelial cells, lactobacilli were recognized by toll-like 2/6 receptors. Lactobacillus crispatus induced NF-κB activation in epithelial cells and did not induce expression of innate immunity mediators IL-8, IL-1β, IL-1α and TNF-α. Lactobacillus crispatus 2029 inhibited IL-8 production in epithelial cells induced by MALP-2 and increased production of anti-inflammatory cytokine IL-6, maintaining the homeostasis of female reproductive tract. Lactobacillus crispatus 2029 produced H2O2 and provided wide spectrum of antagonistic activity increasing colonization resistance to urinary tract infections by bacterial vaginosis and vulvovaginal candidiasis associated agents.

A New Addition to the Cell Plan of Anammox Bacteria: "Candidatus Kuenenia stuttgartiensis" Has a Protein Surface Layer as the Outermost Layer of the Cell

Anammox bacteria perform anaerobic ammonium oxidation (anammox) and have a unique compartmentalized cell consisting of three membrane-bound compartments (from inside outwards): the anammoxosome, riboplasm, and paryphoplasm. The cell envelope of anammox bacteria has been proposed to deviate from typical bacterial cell envelopes by lacking both peptidoglycan and a typical outer membrane. However, the composition of the anammox cell envelope is presently unknown. Here, we investigated the outermost layer of the anammox cell and identified a proteinaceous surface layer (S-layer) (a crystalline array of protein subunits) as the outermost component of the cell envelope of the anammox bacterium "Candidatus Kuenenia stuttgartiensis." This is the first description of an S-layer in the phylum of the Planctomycetes and a new addition to the cell plan of anammox bacteria. This S-layer showed hexagonal symmetry with a unit cell consisting of six protein subunits. The enrichment of the S-layer from the cell led to a 160-kDa candidate protein, Kustd1514, which has no homology to any known protein. This protein is present in a glycosylated form. Antibodies were generated against the glycoprotein and used for immunogold localization. The antiserum localized Kustd1514 to the S-layer and thus verified that this protein forms the "Ca. Kuenenia stuttgartiensis" S-layer.

The T2K Side Muon Range Detector (SMRD)

The T2K experiment is a long baseline neutrino oscillation experiment aiming to observe the appearance of νe in a νμ beam. The νμ beam is produced at the Japan Proton Accelerator Research Complex (J-PARC), observed with the 295km distant Super-Kamiokande Detector and monitored by a suite of near detectors at 280m from the proton target. The near detectors include a magnetized off-axis detector (ND280) which measures the unoscillated neutrino flux and neutrino cross-sections. The present paper describes the outermost component of ND280 which is a Side Muon Range Detector (SMRD) composed of scintillation counters with embedded wavelength shifting fibers and Multi-Pixel Photon Counter readout. The components, performance and response of the SMRD are presented.

Wet-surface–enhanced ellipsometric contrast microscopy identifies slime as a major adhesion factor during bacterial surface motility

In biology, the extracellular matrix (ECM) promotes both cell adhesion and specific recognition, which is essential for central developmental processes in both eukaryotes and prokaryotes. However, live studies of the dynamic interactions between cells and the ECM, for example during motility, have been greatly impaired by imaging limitations: mostly the ability to observe the ECM at high resolution in absence of specific staining by live microscopy. To solve this problem, we developed a unique technique, wet-surface enhanced ellipsometry contrast (Wet-SEEC), which magnifies the contrast of transparent organic materials deposited on a substrate (called Wet-surf) with exquisite sensitivity. We show that Wet-SEEC allows both the observation of unprocessed nanofilms as low as 0.2 nm thick and their accurate 3D topographic reconstructions, directly by standard light microscopy. We next used Wet-SEEC to image slime secretion, a poorly defined property of many prokaryotic and eukaryotic organisms that move across solid surfaces in absence of obvious extracellular appendages (gliding). Using combined Wet-SEEC and fluorescent-staining experiments, we observed slime deposition by gliding Myxococcus xanthus cells at unprecedented resolution. Altogether, the results revealed that in this bacterium, slime associates preferentially with the outermost components of the motility machinery and promotes its adhesion to the substrate on the ventral side of the cell. Strikingly, analogous roles have been proposed for the extracellular proteoglycans of gliding diatoms and apicomplexa, suggesting that slime deposition is a general means for gliding organisms to adhere and move over surfaces.

Role of Cell Wall Polysaccharides during Recognition of Candida albicans by the Innate Immune System

Candida albicans is a dimorphic, opportunistic fungal pathogen responsible for most of the systemic candidiasis reported worldwide. The cell wall is the outermost component of this pathogen, which protects the cell from sudden changes in the external environment, is in close contact with host tissues and cells, and is elaborated by polysaccharides that are not synthesized by human cells. Thus, it is not surprising that the wall is the main source of pathogen-associated molecular patterns that are recognized by immune cells, and recognition of such components is critical for the establishment of a protective anti-Candida response. Here we summarize the current information related to the C. albicans innate immune sensing, underlying the importance of cell wall polysaccharides for the recognition of this pathogen.

Pulse Width Measurements for Pulsars

There are a few methods of measuring pulse widths. Among the most often used pulse widths there are W pp (the distance between two peak value points), W 50 (the width at the place of 50% of the highest peak intensity) and W10 (the width at the place of 10% of the highest peak intensity). In addition, there are also the width W c50 at the place of 50% of their respective intensities and the width Wc10 at the place of 10% of the respective intensities of the two outermost components. The data of the pulse profiles of the sample of 16 double-cone peak pulsars and 7 core-cone triple peak pulsars at 1.4 GHz are utilized to measure 5 kinds of pulse widths. The pulsars with the data of the magnetic inclination α and impact angle β are employed to derive the corresponding radiation beam radius ρ, and the relation between ρ and the pulsar period P, ρ ∝ P −0.5, is verified. Via a comparison between the qualities of the relation between ρ and P derived from the 5 kinds of pulse widths it is found that the width between the outermost components is better than any one of the first 3 kinds of widths, of which the correlative relation obtained from the W c50 width is the best. From this it is considered that W c50 is the measured value that can fully reflect the emission beam width. The symmetry of the pulse profile is also discussed and it is found that from the comparison with the preceding cone emission component the following cone emission component is much closer to the core emission component, and the widths of the two cone emission components are basically the same according to statistics.