scholarly journals Extracellular Proteome Analysis Shows the Abundance of Histidine Kinase Sensor Protein, DNA Helicase, Putative Lipoprotein Containing Peptidase M75 Domain and Peptidase C39 Domain Protein in Leptospira interrogans Grown in EMJH Medium

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 852
Author(s):  
Abhijit Sarma ◽  
Dhandapani Gunasekaran ◽  
Devasahayam Arokia Balaya Rex ◽  
Thoduvayil Sikha ◽  
Homen Phukan ◽  
...  
Keyword(s):  
Culture Medium ◽  
Proteome Analysis ◽  
Dna Helicase ◽  
Extracellular Proteins ◽  
Surface Proteins ◽  
Secretory Proteins ◽  
Extracellular Proteome ◽  
Cell Pellet ◽  
The Difference ◽  
Leptospira Species

Leptospirosis is a re-emerging form of zoonosis that is caused by the spirochete pathogen Leptospira. Extracellular proteins play critical roles in the pathogenicity and survival of this pathogen in the host and environment. Extraction and analysis of extracellular proteins is a difficult task due to the abundance of enrichments like serum and bovine serum albumin in the culture medium, as is distinguishing them from the cellular proteins that may reach the analyte during extraction. In this study, extracellular proteins were separated as secretory proteins from the culture supernatant and surface proteins were separated during the washing of the cell pellet. The proteins identified were sorted based on the proportion of the cellular fractions and the extracellular fractions. The results showed the identification of 56 extracellular proteins, out of which 19 were exclusively extracellular. For those proteins, the difference in quantity with respect to their presence within the cell was found to be up to 1770-fold. Further, bioinformatics analysis elucidated characteristics and functions of the identified proteins. Orthologs of extracellular proteins in various Leptospira species were found to be closely related among different pathogenic forms. In addition to the identification of extracellular proteins, this study put forward a method for the extraction and identification of extracellular proteins.

scholarly journals Proteomics of Protein Secretion by Bacillus subtilis: Separating the “Secrets” of the Secretome

2004 ◽  
Vol 68 (2) ◽  
pp. 207-233 ◽  
Author(s):  
Harold Tjalsma ◽  
Haike Antelmann ◽  
Jan D.H. Jongbloed ◽  
Peter G. Braun ◽  
Elise Darmon ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Protein Secretion ◽  
Cell Envelope ◽  
Extracellular Proteins ◽  
Secretory Proteins ◽  
Bacterial Survival ◽  
Gram Positive ◽  
Extracellular Proteome ◽  
Control Functions ◽  
The Impact

SUMMARY Secretory proteins perform a variety of important“ remote-control” functions for bacterial survival in the environment. The availability of complete genome sequences has allowed us to make predictions about the composition of bacterial machinery for protein secretion as well as the extracellular complement of bacterial proteomes. Recently, the power of proteomics was successfully employed to evaluate genome-based models of these so-called secretomes. Progress in this field is well illustrated by the proteomic analysis of protein secretion by the gram-positive bacterium Bacillus subtilis, for which ∼90 extracellular proteins were identified. Analysis of these proteins disclosed various“ secrets of the secretome,” such as the residence of cytoplasmic and predicted cell envelope proteins in the extracellular proteome. This showed that genome-based predictions reflect only∼ 50% of the actual composition of the extracellular proteome of B. subtilis. Importantly, proteomics allowed the first verification of the impact of individual secretion machinery components on the total flow of proteins from the cytoplasm to the extracellular environment. In conclusion, proteomics has yielded a variety of novel leads for the analysis of protein traffic in B. subtilis and other gram-positive bacteria. Ultimately, such leads will serve to increase our understanding of virulence factor biogenesis in gram-positive pathogens, which is likely to be of high medical relevance.

scholarly journals Scanning Electron-Assisted Dielectric Microscopy Reveals Autophagosome Formation by LC3 and ATG12 in Cultured Mammalian Cells

2021 ◽  
Vol 22 (4) ◽  
pp. 1834
Author(s):  
Tomoko Okada ◽  
Toshihiko Ogura
Keyword(s):  
Mammalian Cells ◽  
Culture Medium ◽  
Related Gene ◽  
Autophagosome Formation ◽  
Intact Cells ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
The Difference ◽  
Related Proteins ◽  
Scanning Electron

Autophagy is an intracellular self-devouring system that plays a central role in cellular recycling. The formation of functional autophagosomes depends on several autophagy-related proteins, including the microtubule-associated proteins 1A/1B light chain 3 (LC3) and the conserved autophagy-related gene 12 (Atg12). We have recently developed a novel scanning electron-assisted dielectric microscope (SE-ADM) for nanoscale observations of intact cells. Here, we used the SE-ADM system to observe LC3- and Atg12-containing autophagosomes in cells labelled in the culture medium with antibodies conjugated to colloidal gold particles. We observed that, during autophagosome formation, Atg12 localized along the actin meshwork structure, whereas LC3 formed arcuate or circular alignments. Our system also showed a difference in the distribution of LC3 and Atg12; Atg12 was broadly distributed while LC3 was more localized. The difference in the spatial distribution demonstrated by our system explains the difference in the size of fluorescent spots due to the fluorescently labelled antibodies observed using optical microscopy. The direct SE-ADM observation of cells should thus be effective in analyses of autophagosome formation.

SHEDDING OF SURFACE PROTEINS BY PORCINE THYROID CELLS

1980 ◽  
Vol 85 (2) ◽  
pp. 245-251 ◽  
Author(s):  
A. BRENNAN ◽  
P. M. POVEY ◽  
B. REES SMITH ◽  
R. HALL
Keyword(s):  
Cell Surface ◽  
Sodium Dodecyl Sulphate ◽  
Culture Medium ◽  
Cell Metabolism ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Half Time ◽  
Thyroid Cells ◽  
Peptide Cleavage ◽  
Membrane Bound

Isolated porcine thyroid cells were surface-labelled with 125I using the lactoperoxidase technique. Samples of the cells were then cultured and harvested at various intervals for up to 7 days. The labelled proteins remaining on the cells or shed into the culture medium were analysed by electrophoresis on polyacrylamide gels run in sodium dodecyl sulphate. These studies indicated that the several different surface proteins of the thyroid cells were lost from the cell surface at similar rates (half-time of approximately 28 h) as the result, at least in part, of a process which depended on active cell metabolism. In addition, the gel profiles obtained from analysis of both medium and membrane-bound labelled proteins were similar and this suggested that peptide cleavage was not involved in the shedding of the majority of these proteins.

scholarly journals Construction and Characterization of anagr Deletion Mutant of Staphylococcus epidermidis

2000 ◽  
Vol 68 (3) ◽  
pp. 1048-1053 ◽  
Author(s):  
Cuong Vuong ◽  
Friedrich Götz ◽  
Michael Otto
Keyword(s):  
Staphylococcus Epidermidis ◽  
Deletion Mutant ◽  
Protein Pattern ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Accessory Gene ◽  
Accessory Gene Regulator ◽  
Sds Page ◽  
The Difference

ABSTRACT The physiological significance of the accessory gene regulator (agr) system of Staphylococcus epidermidis was investigated by construction of an agr deletion mutant via allelic replacement with a spectinomycin resistance cassette. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the protein pattern was strongly altered in the mutant; the amounts of most surface proteins were higher, whereas the amounts of most exoproteins were lower. The agrsystem of S. epidermidis thus appears to have an important impact on growth phase-dependent protein synthesis as has been shown for Staphylococcus aureus. The activity of the exoenzymes lipase and protease, assumed to be involved in staphylococcal pathogenicity, was investigated by agar diffusion assays and SDS-PAGE activity staining. A general reduction of these enzyme activities in the agr mutant was found. The difference in overall lipase activity was small, but zymographic analysis suggested a clear defect in lipase processing in the agr mutant.

Proteome Analysis of Colorectal Cancer Cell Line SW480 Released Extracellular Vesicles

2018 ◽  
Vol 762 ◽  
pp. 3-7
Author(s):  
Ilva Nakurte ◽  
Kaspars Jekabsons ◽  
Elina Zandberga ◽  
Arturs Abols ◽  
Aija Line ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Extracellular Vesicles ◽  
Cancer Cell Line ◽  
Surface Protein ◽  
Proteome Analysis ◽  
Research Area ◽  
Surface Proteins ◽  
Colorectal Cancer Cell Line ◽  
Protein Fragments ◽  
Early Cancer Diagnosis

The detection and profiling of disease-specific extracellular vesicles (EVs) from body fluids has been challenging research area during recent years. However, the question – can EVs surface proteins be exploited as a credible tool for early cancer diagnosis – is still not answered. Objective of the current study was to find out whether hypoxia induces differences in protein profiles of EVs released from hypoxic human colorectal cancer cells SW480 (EVHyp) and EVs released from these cells grown in normoxic conditions – EVNorm. Obtained results show differences in EVs surface protein samples. Some protein fragments were found only or mostly in EVHyp surface protein samples. Finding of one or two such EVHyp protein fragments allows us to suggest that deciphered EVHyp surface proteins might be indices of hypoxia-induced proteome changes and might serve as a hint to find a cancer specific protein.

scholarly journals Uropathogenic Escherichia coli Biofilm-Forming Capabilities are not Predictable from Clinical Details or from Colonial Morphology

Diseases ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 11 ◽  
Author(s):  
Shane Whelan ◽  
Mary Claire O’Grady ◽  
Dan Corcoran ◽  
Karen Finn ◽  
Brigid Lucey
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Culture Medium ◽  
Recurrent Infection ◽  
Positive Control ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
Recurrent Uti ◽  
Colonial Morphology ◽  
The Difference

Antibiotic resistance is increasing to an extent where efficacy is not guaranteed when treating infection. Biofilm formation has been shown to complicate treatment, whereby the formation of biofilm is associated with higher minimum inhibitory concentration values of antibiotic. The objective of the current paper was to determine whether biofilm formation is variable among uropathogenic Escherichia coli isolates and whether formation is associated with recurrent urinary tract infection (UTI), and whether it can be predicted by phenotypic appearance on culture medium A total of 62 E. coli isolates that were reported as the causative agent of UTI were studied (33 from patients denoted as having recurrent UTI and 29 from patients not specified as having recurrent UTI). The biofilm forming capability was determined using a standard microtitre plate method, using E. coli ATCC 25922 as the positive control. The majority of isolates (93.6%) were found to be biofilm formers, whereby 81% were denoted as strong or very strong producers of biofilm when compared to the positive control. Through the use of a Wilcox test, the difference in biofilm forming propensity between the two patient populations was found to not be statistically significant (p = 0.5). Furthermore, it was noted that colony morphology was not a reliable predictor of biofilm-forming propensity. The findings of this study indicate that biofilm formation is very common among uropathogens, and they suggest that the biofilm-forming capability might be considered when treating UTI. Clinical details indicating a recurrent infection were not predictors of biofilm formation.

scholarly journals Multicompartment modeling of protein shedding kinetics during vascularized tumor growth

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gautam B. Machiraju ◽  
Parag Mallick ◽  
Hermann B. Frieboes
Keyword(s):  
Tumor Growth ◽  
Compartment Model ◽  
Vessel Diameter ◽  
Cellular Protein ◽  
Extracellular Proteins ◽  
Surface Proteins ◽  
Ca 125 ◽  
Model Parameters ◽  
Marker Selection ◽  
Protein Shedding

Abstract Identification of protein biomarkers for cancer diagnosis and prognosis remains a critical unmet clinical need. A major reason is that the dynamic relationship between proliferating and necrotic cell populations during vascularized tumor growth, and the associated extra- and intra-cellular protein outflux from these populations into blood circulation remains poorly understood. Complementary to experimental efforts, mathematical approaches have been employed to effectively simulate the kinetics of detectable surface proteins (e.g., CA-125) shed into the bloodstream. However, existing models can be difficult to tune and may be unable to capture the dynamics of non-extracellular proteins, such as those shed from necrotic and apoptosing cells. The models may also fail to account for intra-tumoral spatial and microenvironmental heterogeneity. We present a new multi-compartment model to simulate heterogeneously vascularized growing tumors and the corresponding protein outflux. Model parameters can be tuned from histology data, including relative vascular volume, mean vessel diameter, and distance from vasculature to necrotic tissue. The model enables evaluating the difference in shedding rates between extra- and non-extracellular proteins from viable and necrosing cells as a function of heterogeneous vascularization. Simulation results indicate that under certain conditions it is possible for non-extracellular proteins to have superior outflux relative to extracellular proteins. This work contributes towards the goal of cancer biomarker identification by enabling simulation of protein shedding kinetics based on tumor tissue-specific characteristics. Ultimately, we anticipate that models like the one introduced herein will enable examining origins and circulating dynamics of candidate biomarkers, thus facilitating marker selection for validation studies.

scholarly journals Hypoxic Response of Mycobacterium tuberculosis Studied by Metabolic Labeling and Proteome Analysis of Cellular and Extracellular Proteins

2002 ◽  
Vol 184 (13) ◽  
pp. 3485-3491 ◽  
Author(s):  
Ida Rosenkrands ◽  
Richard A. Slayden ◽  
Janne Crawford ◽  
Claus Aagaard ◽  
Clifton E. Barry ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Proteome Analysis ◽  
Peptide Mass Fingerprinting ◽  
Extracellular Proteins ◽  
Metabolic Labeling ◽  
Low Oxygen ◽  
Hypoxic Response ◽  
Peptide Mass ◽  
Oxygen Conditions

ABSTRACT The events involved in the establishment of a latent infection with Mycobacterium tuberculosis are not fully understood, but hypoxic conditions are generally believed to be the environment encountered by the pathogen in the central part of the granuloma. The present study was undertaken to provide insight into M. tuberculosis protein expression in in vitro latency models where oxygen is depleted. The response of M. tuberculosis to low-oxygen conditions was investigated in both cellular and extracellular proteins by metabolic labeling, two-dimensional electrophoresis, and protein signature peptide analysis by liquid chromatography-mass spectrometry. By peptide mass fingerprinting and immunodetection, five proteins more abundant under low-oxygen conditions were identified from several lysates of M. tuberculosis: Rv0569, Rv2031c (HspX), Rv2623, Rv2626c, and Rv3841 (BfrB). In M. tuberculosis culture filtrates, two additional proteins, Rv0363c (Fba) and Rv2780 (Ald), were found in increased amounts under oxygen limitation. These results extend our understanding of the hypoxic response in M. tuberculosis and potentially provide important insights into the physiology of the latent bacilli.

A new strategy for efficient secretory expression of extracellular proteins into culture medium of E. coli

2008 ◽  
Vol 136 ◽  
pp. S719-S720 ◽  
Author(s):  
Jing Wu ◽  
Zhaofeng Li ◽  
Bin Li ◽  
Cheng Cheng ◽  
Jian Chen
Keyword(s):  
Culture Medium ◽  
Extracellular Proteins ◽  
Secretory Expression ◽  
E Coli ◽  
New Strategy

scholarly journals Invasion and Killing of Human Endothelial Cells by Viridans Group Streptococci

2003 ◽  
Vol 71 (5) ◽  
pp. 2365-2372 ◽  
Author(s):  
Murray W. Stinson ◽  
Susan Alder ◽  
Sarmishtha Kumar
Keyword(s):  
Endothelial Cells ◽  
Infective Endocarditis ◽  
Culture Medium ◽  
Umbilical Vein ◽  
Bovine Liver ◽  
Surface Proteins ◽  
Oral Streptococci ◽  
Bovine Liver Catalase ◽  
Umbilical Vein Endothelial Cells ◽  
Viridans Group Streptococci

ABSTRACT Colonization of the cardiovascular endothelium by viridans group streptococci can result in infective endocarditis and possibly atherosclerosis; however, the mechanisms of pathogenesis are poorly understood. We investigated the ability of selected oral streptococci to infect monolayers of human umbilical vein endothelial cells (HUVEC) in 50% human plasma and to produce cytotoxicity. Planktonic Streptococcus gordonii CH1 killed HUVEC over a 5-h period by peroxidogenesis (alpha-hemolysin) and by acidogenesis but not by production of protein exotoxins. HUVEC were protected fully by addition of supplemental buffers and bovine liver catalase to the culture medium. Streptococci were also found to invade HUVEC by an endocytic mechanism that was dependent on polymerization of actin microfilaments and on a functional cytoskeleton, as indicated by inhibition with cytochalasin D and nocodazole. Electron microscopy revealed streptococci attached to HUVEC surfaces via numerous fibrillar structures and bacteria in membrane-encased cytoplasmic vacuoles. Following invasion by S. gordonii CH1, HUVEC monolayers showed 63% cell lysis over 4 h, releasing 64% of the total intracellular bacteria into the culture medium; however, the bacteria did not multiply during this time. The ability to invade HUVEC was exhibited by selected strains of S. gordonii, S. sanguis, S. mutans, S. mitis, and S. oralis but only weakly by S. salivarius. Comparison of isogenic pairs of S. gordonii revealed a requirement for several surface proteins for maximum host cell invasion: glucosyltransferase, the sialic acid-binding protein Hsa, and the hydrophobicity/coaggregation proteins CshA and CshB. Deletion of genes for the antigen I/II adhesins, SspA and SspB, did not affect invasion. We hypothesize that peroxidogenesis and invasion of the cardiovascular endothelium by viridans group streptococci are integral events in the pathogenesis of infective endocarditis and atherosclerosis.

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