Serogroups of the beer spoilage bacterium Megasphaera cerevisiae correlate with the molecular weight of the major EDTA-extractable surface protein

2000 ◽  
Vol 46 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Barry Ziola ◽  
Lori Gee ◽  
Nancy N Berg ◽  
Sun Y Lee

Megasphaera cerevisiae is a Gram-negative obligate anaerobe that causes turbidity and off-flavour and aroma in beer. Seven isolates of M. cerevisiae were obtained worldwide, and their extractable surface antigens were focused upon to determine if there is more than one serogroup of this bacterium. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of ethylenediaminetetraacetic acid (EDTA) bacterial extracts revealed a predominant protein with apparent molecular weights of 46 000, 45 000, and 43 000 for three, two, and two isolates, respectively. When mouse antiserum generated against any of the EDTA extracts was reacted with denatured bacterial proteins in immunoblots, all bacterial isolates exhibited extensive cross-reactivity involving three antigens, one being the major EDTA-extractable protein. In contrast, when the sera were tested for surface reactivity with intact bacteria, three cross-reactivity groups were observed, with the groups individually comprised of bacteria having the same size major EDTA-extractable surface protein. When BALB/c mice immunized with a bacterium from each of the three serogroups were used for monoclonal antibody (Mab) hybridoma production, bacterial surface-reactive Mabs were obtained whose reactivities parallel the three polyclonal antibody-defined serogroups. Through combining these surface-reactive Mabs, it will be possible to rapidly detect and identify beer contamination by M. cerevisiae belonging to any serogroup. Key words: beer spoilage bacteria, Megasphaera cerevisiae, monoclonal antibodies, surface proteins, serogroups.

1974 ◽  
Vol 140 (3) ◽  
pp. 345-354 ◽  
Author(s):  
Robert E. Cone ◽  
John J. Marchalonis

Accessible surface proteins of thymus-derived lymphocytes (T-cells) of normal CBA mice and bone-marrow-derived lymphocytes (B-cells) of congenitally athymic nu/nu mice were analysed. The surfaces of lymphocytes were radioiodinated by using the enzyme lactoperoxidase (EC 1.11.1.7), then solubilized either in acid–urea or in the non-ionic detergent Nonidet P-40. These lysates were then precipitated with antisera specific to either immunoglobulin or the θ-alloantigen in order to assess the presence of these surface markers. Comparable amounts of radioactivity in proteins specifically precipitable as immunoglobulin were obtained from T-lymphocytes and B-lymphocytes when the cells were disrupted by acid–urea. This immunoglobulin had mol. wt. approx. 180000 and was composed of light chains and μ-type heavy chains. When radioiodinated lymphocytes were solubilized with Nonidet P-40, 3–4% of radioiodinated high-molecular-weight protein of B-cells consisted of immunoglobulin, a result similar to that found with acid–urea extraction. However, with the detergent extraction, only 0.1% of T-cell surface protein was precipitable by anti-globulin reagents. The θ-alloantigen was isolated from CBA T-cells both by acid–urea and by detergent lysis. This protein possessed a mobility on polyacrylamide-gel electrophoresis in sodium dodecyl sulphate which was consistent with a mol. wt. of 60000. An identical component was isolated from the θ-positive thymoma WEHI 105. The θ-antigen was not isolated from B-cells by either of the extraction procedures used. These results provide further evidence that the surface membranes of normal T-cells and B-cells differ in physicochemical properties. In particular, various surface components possess differential solubilities in non-ionic or organic solvents. This observation provides an explanation for discrepant results that have appeared in the literature concerning the isolation of immunoglobulin from T-lymphocytes.


Parasitology ◽  
1997 ◽  
Vol 115 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Y. SPIEGEL ◽  
I. KAHANE ◽  
L. COHEN ◽  
E. SHARON

Characterization of surface coat (SC) proteins including carbohydrate-binding proteins and glycoproteins of the plant-parasitic nematode Meloidogyne javanica 2nd-stage juvenile (J2) is reported. Extraction of surface proteins with sodium dodecyl sulfate (SDS) and separation by denaturing polyacrylamide gel electrophoresis (SDS–PAGE) results with bands at 6, 9, 14, 22, 26, 31, 46, 49, 58, 66, 80, 205 and 250 kDa. On Western blots, the neoglycoprotein, fucosylated-, mannosylated- and glucosylated-bovine serum albumin, reacted with the 14, 22, 26, 58 and 66 kDa bands. The lectins, Concanavalin A and wheat-germ agglutinin (WGA) labelled surface protein bands of 6, 9, 14, 31, 58 and 66 kDa; WGA also labelled the 22 and 26 kDa bands. Biotin reagents were used to specifically trace surface proteins on live J2. SDS–PAGE of biotinylated J2 extracts revealed only 2 specific biotin-protein bands at 46 and 49 kDa. The labile and transitory nature of Meloidogyne javanica SC was demonstrated by the dynamics of human red blood cells (HRBC) adherence to J2 of different ages. HRBC adherence was also used to demonstrate the SC recovery of detergent-treated J2, which was further exhibited in the SDS–PAGE profiles.


2021 ◽  
Vol 9 (8) ◽  
pp. 1587
Author(s):  
Matteo Dell’Anno ◽  
Carlotta Giromini ◽  
Serena Reggi ◽  
Mariagrazia Cavalleri ◽  
Alessandra Moscatelli ◽  
...  

Limosilactobacillus reuteri and Lactiplantibacillus plantarum strains, previously isolated from weaned piglets, were considered for the evaluation of their adhesive characteristics. Lactobacilli were treated with LiCl in order to remove the surface protein layer, and probiotic activity was compared with those of untreated strains. The autoaggregation, co-aggregation to E. coli F18+, and adhesive abilities of LiCl-treated Limosilactobacillus reuteri and Lactiplantibacillus plantarum were significantly inhibited (p < 0.05) compared with the respective untreated strain. The hydrophobic and basic phenotypes were observed due to the strong affinity to chloroform and low adherence to ethyl acetate. In particular, L. plantarum showed higher hydrophobicity compared to L. reuteri, which may reflect their different colonizing ability. After treatment with LiCl to remove surface proteins, the adherence capabilities of L. reuteri and L. casei on IPEC-J2 cells decreased significantly (p < 0.001) and L. reuteri adhered more frequently. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that both L. reuteri and L. plantarum had several bands ranging from 20 to 100 kDa. Two-dimensional gel electrophoresis showed an acidic profile of the surface-layer polypeptides for both bacterial strains, and more studies are needed to characterize their profile and functions. The results confirm the pivotal role of surface proteins in the probiotic potential of L. reuteri and L. plantarum.


1986 ◽  
Vol 64 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Malcolm B. Perry ◽  
Leann MacLean ◽  
Douglas W. Griffith

The phenol-phase soluble lipopolysaccharide isolated from Escherichia coli 0:157 by the hot phenol–water extraction procedure was shown by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, periodate oxidation, methylation, and 13C and 1H nuclear magnetic resonance studies to be an unbranched linear polysaccharide with a tetrasaccharide repeating unit having the structure:[Formula: see text]The serological cross-reactivity of E. coli 0:157 with Brucella abortus, Yersinia enterocolitica (serotype 0:9), group N Salmonella, and some other E. coli species can be related immunochemically to the presence of 1,2-glycosylated N-acylated 4-amino-4,6-dideoxy-α-D-mannopyranosyl residues in the O-chains of their respective lipopolysaccharides.


1986 ◽  
Vol 6 (9) ◽  
pp. 3240-3245
Author(s):  
G A Bannon ◽  
R Perkins-Dameron ◽  
A Allen-Nash

The presence of specific proteins (known as immobilization antigens) on the surface of the ciliated protozoan Tetrahymena thermophila is under environmental regulation. There are five different classes (serotypes) of surface proteins which appear on the cell surface when T. thermophila is cultured under different conditions of temperature or incubation medium; three of these are temperature dependent. The appearance of these proteins on the cell surface is mutually exclusive. We used polyclonal antibodies raised against 30 degrees C (designated SerH3)- and 40 degrees C (designated SerT)-specific surface antigens to study their structure and expression. We showed that these surface proteins contain at least one disulfide bridge. On sodium dodecyl sulfate-denaturing polyacrylamide gels, the nonreduced 30 degrees C- and 40 degrees C-specific surface proteins migrated with molecular sizes of 69 and 36 kilodaltons, respectively. The reduced forms of the proteins migrated with molecular sizes of 58 and 30 kilodaltons, respectively. The synthesis of the surface proteins responded rapidly and with a time course similar to that of the incubation temperature. The synthesis of each surface protein was greatly reduced within 1 h and undetectable by 2 h after a shift to the temperature at which the protein is not expressed. Surface protein synthesis resumed by the end of 1 h after a shift to the temperature at which the protein is expressed. The temperature-dependent induction of these surface proteins appears to be dependent on the synthesis of new mRNA, as indicated by a sensitivity to actinomycin D. Surface protein syntheses were mutually exclusive except at a transition temperature. At 35 degrees C both surface proteins were synthesized by a cell population. These data support the potential of this system as a model for the study of the effects of environmental factors on the genetic regulation of cell surface proteins.


2020 ◽  
Vol 67 (2) ◽  
Author(s):  
Snatashree Mohanty ◽  
M. Makesh ◽  
K. V. Rajendran ◽  
P. P. Suresh Babu ◽  
Deepika Anand ◽  
...  

Serum immunoglobulins (Ig) of mrigal Cirrhinus mrigala (Hamilton 1822) immunised with bovine serum albumin (BSA), were purified by affinity chromatography using BSA-CL agarose column. The purified mrigal Ig (m-Ig) was characterised under reducing condition by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) which revealed two bands of 85 and 26 kDa corresponding to heavy and light chain, respectively. Following fusion of splenocytes from Balb/c mice immunised with purified m-Ig with myeloma cells, three hybridomas showing reactivity with m-Ig were cloned by limiting dilution. The monoclonal antibodies (MAbs) generated by these clones were designated as 3B2-E12, 3B2-F9 and 4C3-B2 and characterised by western blotting and isotyping. Western blot analysis of the supernatant from the three clones with purified m-Ig indicated that, all the three MAbs were specific to heavy chain. Isotyping revealed that 3B2-E12 MAb was of IgG1 isotype whereas the other two MAbs were of IgG2a isotype. Cross reactivity of anti-mrigal Ig MAb (3B2-E12) was observed with serum Ig of Catla catla and Labeo rohita indicating semi-conserved nature of Ig in Indian major carps.


2019 ◽  
Vol 25 (3) ◽  
pp. 310-319
Author(s):  
Yuan Dong ◽  
Hanjin Hou ◽  
An Chen ◽  
Wei Ma ◽  
Moli Yin ◽  
...  

D-dimer is an essential diagnostic index of thrombotic diseases. Since the existing anti-D-dimer antibodies vary in quality and specificity, a search for alternative anti-D-dimer antibodies is required. The present study aimed to screen a novel monoclonal antibody (mAb) against D-dimer using a light-initiated chemiluminescence assay (LiCA). In this work, mice were immunized with antigen prepared from human plasma by enzyme hydrolysis. After screening, a novel mAb, DD 2G11, was obtained. The results of sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis indicated that DD 2G11 could be used as a standard marker for D-dimer. The isotype of DD 2G11 was IgG1, the Ka value was 0.646 nM-1, and the Kd value was 50 nM, indicating that the binding affinity to D-dimer was very high. Furthermore, no cross-reactivity between DD 2G11 and other fibrinogen degradation products (FgDPs) was found. Finally, the correlation between DD 2G11 and the reference antibody (commercial antibody) was investigated by analyzing 56 clinical samples using a latex-enhanced turbidimetric immunoassay (LTIA). The R2 value of the linear regression was 0.94538, indicating that DD 2G11 met clinical requirements. In conclusion, the present study provides a more expeditious protocol to screen mAbs and provides a clinically usable mAb against D-dimer.


Blood ◽  
1983 ◽  
Vol 61 (6) ◽  
pp. 1072-1080 ◽  
Author(s):  
B Rucinski ◽  
A Poggi ◽  
P James ◽  
JC Holt ◽  
S Niewiarowski

Abstract Two heparin-neutralizing proteins secreted by thrombin-stimulated platelets were purified to homogeneity by means of heparin-agarose affinity chromatography. These proteins, termed porcine platelet basic protein (PBP) and porcine platelet factor 4 (PF4), were eluted from a heparin-agarose column at 0.6–0.9 M NaCl and at 1–1.4 M NaCl, respectively. The molecular weight of porcine platelet basic protein was 7,000–7,700 daltons, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and amino acid analysis. The isoelectric point of this protein was at pH 9.0. The amino acid composition of porcine platelet basic protein resembled that of human low affinity platelet factor 4 (LA-PF4), except that the porcine protein did not contain tyrosine. The molecular weight of porcine platelet factor 4 ranged from 10,000 (estimated from amino acid analysis) to 14,000 (estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis). The amino acid compositions of human platelet factor 4 and of porcine platelet factor 4 were similar. Monospecific antibodies against porcine platelet factor 4 and porcine platelet basic protein were raised in rabbits. Competitive radioimmunoassay demonstrated a low but significant immunologic cross-reactivity between human and porcine platelet factor 4, and between porcine platelet basic protein and a group of human secreted platelet proteins that bind to heparin with low affinity (beta-thromboglobulin [beta TG] and low affinity platelet factor 4). Experiments with direct immuno- precipitation of 125I-labeled antigens suggested that all four proteins investigated (human platelet factor 4, porcine platelet factor 4, human low affinity platelet factor 4 or human beta-thromboglobulin, and porcine platelet basic protein) share common antigenic determinants. However, there was a higher degree of immunologic cross-reactivity between heterologous antigens with similar heparin binding affinity (human platelet factor 4 and porcine platelet factor 4) than between heterologous antigens with different binding affinity (human platelet factor 4 and porcine platelet basic protein). In conclusion, our finding suggests a significant structural homology among the four proteins.


Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 496-500 ◽  
Author(s):  
M Wolf ◽  
C Boyer ◽  
A Tripodi ◽  
D Meyer ◽  
MJ Larrieu ◽  
...  

Abstract A qualitative defect of antithrombin III (AT III) has been demonstrated over three generations in eight members of an Italian family by the discrepancy between a normal amount of antigen and decreased antithrombin and anti-Xa activity in the presence or in the absence of heparin. By two-dimensional immunoelectrophoresis in the absence of heparin, two peaks of AT III were present in all patients' plasma. AT III was purified from normal and propositus plasma by sulfate dextran precipitation followed by heparin affinity chromatography. The elution profile of the patient's AT III was abnormal and allowed the separation of two populations of AT III, normal and abnormal. The first fraction (normal AT III) contained AT III activity, migrated as a single peak by two-dimensional immunoelectrophoresis and by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), demonstrated a single band with a molecular weight (mol wt) identical to that of normal AT III (60,000). Conversely, the last fraction, devoid of AT III activity, migrated as a single abnormal peak by two-dimensional immunoelectrophoresis in the absence of heparin. By SDS-PAGE, two bands were observed: one with a mol wt of 60,000 and a second one with a mol wt of 120,000. Western blots clearly demonstrated cross-reactivity of the 120,000 and 60,000 mol wt bands with monospecific antisera to human AT III. Reduction of the 120,000 mol wt band converted it to a single 60,000 mol wt band, suggesting the presence of an abnormal dimeric form of AT III. The name AT III Milano is proposed for this new variant.


2000 ◽  
Vol 68 (3) ◽  
pp. 1048-1053 ◽  
Author(s):  
Cuong Vuong ◽  
Friedrich Götz ◽  
Michael Otto

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.


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