scholarly journals Cleavage of bacterial flagellin with cyanogen bromide. Antigenic properties of the protein fragments

1969 ◽  
Vol 113 (3) ◽  
pp. 501-506 ◽  
Author(s):  
C. R. Parish ◽  
R. Wistar ◽  
G. L. Ada
Keyword(s):  
Cyanogen Bromide ◽  
Antigenic Determinants ◽  
Protein Fragments ◽  
Antigenic Activity ◽  
Antigenic Properties ◽  
Bacterial Immobilization ◽  
Test Fragment

1. Four polypeptide fragments, obtained by cyanogen bromide treatment of the protein flagellin from Salmonella adelaide, were tested for their antigenic activity by using them as inhibitors in three different assays: bacterial immobilization, haemagglutination of sensitized erythrocytes and quantitative micro precipitation. Immunodiffusion studies were also performed on the protein fragments. 2. Cleavage of the flagellin molecule in this way gave no detectable loss of antigenic determinants. Fragment A (mol.wt. 18000), the largest of the polypeptides, contained all the antigenic specificities present on flagellin that were recognized by the antisera used. In one test, fragment B (mol.wt. 12000) also contained antigenic activity to an extent not easily explainable by contamination with fragment A. Fragments C (mol.wt. 5500) and D (mol.wt. 4500) appeared to be antigenically inactive.

Immunochemical properties of trypsin fragments of human thyroglobulin

1980 ◽  
Vol 94 (2) ◽  
pp. 188-195 ◽  
Author(s):  
R. Dominici ◽  
G. B. Salabé ◽  
A. Diodato ◽  
M. Sorcini ◽  
M. G. di Iorio ◽  
...  
Keyword(s):  
Gel Filtration ◽  
Rabbit Antiserum ◽  
Antigenic Determinants ◽  
Good Activity ◽  
Autoimmune Process ◽  
Autoimmune Thyroid Diseases ◽  
Autoimmune Thyroid ◽  
Tryptic Digest ◽  
Antigenic Activity ◽  
Antigenic Properties

Abstract. Purified human thyroglobulin (Tg) was enzymatically digested with trypsin. After completion of digestion, the tryptic digest was fractionated by gel filtration on a Biogel A 1.5 m column. Further separation and isolation of the major peak C was carried out on a Sephadex G-75 column. Nine fractions were separated and antigenic properties evaluated by a specific and sensitive radioimmunoassay using a rabbit antiserum to 19S Tg and three different antisera from patients with autoimmune thyroid diseases. The Tg fragments react with both hetero- and auto-antisera. The highest antigenic activity was found on larger fragments, but a fairly good activity was also observed on fragments (C6, C7) with lower molecular weight. Antigenic determinants of Tg differ in individual sera suggesting that different sets of determinants elicit the autoimmune process.

scholarly journals Immunochemical characterization of human plasma fibronectin

1980 ◽  
Vol 191 (3) ◽  
pp. 719-727 ◽  
Author(s):  
M Vuento ◽  
E Salonen ◽  
K Salminen ◽  
M Pasanen ◽  
U K Stenman
Keyword(s):  
Human Plasma ◽  
Antigenic Structure ◽  
Antigenic Determinants ◽  
Proteolytic Degradation ◽  
Plasma Fibronectin ◽  
Native Protein ◽  
Covalent Interaction ◽  
Antigenic Activity ◽  
Haemagglutinating Activity

Human plasma fibronectin has been purified by a non-denaturing affinity chromatography procedure [Vuento & Vaheri, (1979) Biochem.J. 183, 331–337], and antisera have been raised by immunizing rabbits with the native protein. The antisera reacted strongly with native fibronectin, but only weakly with reduced and alkylated fibronectin or with heat-denaturated fibronectin. Denaturation also affected the haemagglutinating and gelatin-binding activities of fibronectin and increased its susceptibility to proteolytic degradation. The antisera reacted with fragments of fibronectin obtained by proteolysis with plasmin. Large fragments (mol.wt. 180000–200000), lacking the region harbouring the interchain disulphide bridges but containing the sites responsible for gelatin-binding and haemagglutinating activity, showed as intense a reaction with the antisera as intact fibronectin. Smaller peptides showed a weaker reaction. All fragments tested showed sensitivity to denaturation in their reaction with the antisera. The results were interpreted as showing that: (1) native fibronectin has an ordered conformation that is easily perturbed by denaturation; (2) most of the antigenic determinants of the protein are dependent on conformation; (3) the region of the fibronectin molecule containing the interchain disulphide bridges has only few antigenic determinants; and (4) covalent interaction of the two subunits does not contribute to the antigenic structure recognized by rabbit antisera. The observed correlation between the antigenic activity and a structural and functional intactness of fibronectin suggests that the antibodies to native fibronectin could be used as a conformational probe in studies on this protein.

scholarly journals Shared Antigenic Determinants Between Spermatozoa and Bacteria: An Experimental Study

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Escherichia Coli ◽  
Experimental Study ◽  
Streptococcus Pyogenes ◽  
Secretory Protein ◽  
Antigenic Determinants ◽  
Morphological Alterations ◽  
Bacterial Immobilization ◽  
Sperm Immobilization ◽  
Motile Bacteria

Sperm immobilization factor (SIF), the secretory protein of Staphylococcus aureus, is known to cause complete immobilization, death and morphological alterations in mouse spermatozoa in vitro. However, the present study aims to explore a newer dimension of SIF i.e., to bind to motile and non-motile bacteria and its ability to induce immobilization of motile bacteria in vitro. The results showed that 800µg of SIF caused complete immobilization of motile bacteria, however, death and morphological alterations could not be observed even with 1000µg of SIF. Furthermore, this SIF-mediated bacterial immobilization was reversed when each of the SIF-binding receptor from mouse spermatozoa and bacteria (Escherichia coli and Streptococcus pyogenes) was incubated with bacteria, thereby, providing an experimental evidence of similarity between the antigenic determinants present on spermatozoa and bacteria against a common ligand, SIF.

scholarly journals IMMUNOCHEMICAL ANALYSIS OF RECOMBINANT CHIMERIC POLYPEPTIDE OspCgar+afz OF BORRELIA GARINII AND B. AFZELIIISOLATES

2016 ◽  
pp. 37-44
Author(s):  
VS. .. Karavaev ◽  
E. S. Oleinikova ◽  
M. Sh. Azaev ◽  
A. B. Beklemishev'
Keyword(s):  
Recombinant Proteins ◽  
Western Siberia ◽  
West Siberia ◽  
Amino Acid Sequences ◽  
Borrelia Garinii ◽  
Test Systems ◽  
Antigenic Activity ◽  
Escherichia Coli Cells ◽  
Antigenic Properties ◽  
Chimeric Polypeptide

Aim. Comparative study of antigenic properties of recombinant proteins OspCgar and OspCafz and recombinant chimeric polypeptide OspCgar+afZ, that contains amino acid sequences of mature immune dominant OspC proteins of West-Siberian isolates of Borrelia garinii (OspCgar) and B. afzelii (OspCafz), and evaluation of possibility of their use as antigens during creation of test-systems for serodiagnostics of Lyme borreliosis (LB) on the territory of Western Siberia. Materials and methods. Recombinant chimeric polypeptide OspCgar+afz and recombinant mature proteins OspCgar and OspCafz, obtained by expression of the corresponding genes in Escherichia coli cells, purified by affinity chromatography in Ni-NTA-sepharose CL-6B and studied by EIA method for the ability to bind antibodies from sera of LB patients. Results. A difference in sensitivity of determination by EIA method of specific IgM and IgG against borreliae in blood sera of LB patients with localized stage of the disease during use of OspCgar, OspCafz and OspCgar+afZ chimera as antigens was shown. Chimeric antigen OspCgar+afz was established to show higher antigenic activity compared with each of the OspCgar or OspCafZ antigens separately. Conclusion. The results of the study allow to examine the recombinant chimeric polypeptide OspCgar+afz as a possible component during creation of test-systems for serodiagnostics of LB on the territory of West Siberia.

scholarly journals IMMUNE RESPONSE TO CHEMICALLY MODIFIED FLAGELLIN

1971 ◽  
Vol 134 (1) ◽  
pp. 21-47 ◽  
Author(s):  
C. R. Parish
Keyword(s):  
Immune Response ◽  
Antibody Formation ◽  
Delayed Type Hypersensitivity ◽  
Antigenic Determinants ◽  
Cell Mediated Immunity ◽  
Specific Cell ◽  
Adult Rats ◽  
Antigenic Activity ◽  
Cellular Immune ◽  
Derivatives Of

Flagellin (mol.wt. 40,000) from S. adelaide organisms and a series of acetoacetyl derivatives of flagellin were tested for their ability to induce humoral and cell-mediated immunity in adult rats. It was found that unmodified flagellin was an excellent inducer of antibody formation but a poor inducer of delayed-type hypersensitivity. In contrast, increasing acetoacetylation steadily destroyed the ability of flagellin to initiate antibody formation but enhanced the capacity of the molecule to induce flagellin-specific cell-mediated immunity and antibody tolerance. In fact, it appeared that in adult rats antibody formation and cell-mediated immunity may well be opposing immunological processes. Furthermore, the affinity of the acetoacetyl flagellins for anti-flagellin antibodies appeared to determine the type of immune response which predominated. High affinity antigen produced antibody formation whereas low affinity antigen induced cell-mediated immunity and antibody tolerance. The importance of affinity was further evidenced by the fact that a CNBr digest of flagellin induced humoral and cellular immune responses identical to an acetoacetylated flagellin of comparable antigenic activity. From these studies it was proposed that both humoral and cell-mediated immunity can be directed against the same antigenic determinants but that the specificity requirements for delayed hypersensitivity (and antibody tolerance) are less than those required for antibody formation. Some remarkable immunological features of the flagellin system were revealed. Flagellin induced comparable delayed-type hypersensitivity when injected in either saline or FCA. Furthermore, FCA only slightly enhanced the delayed responses induced by the acetoacetyl flagellins and in fact these preparations produced antibody tolerance whether injected in saline or adjuvant. Finally, in contrast to the adult tolerance induced by the acetoacetylated flagellins, which existed only at the antibody level, tolerance in neonatal rats existed at the level of both humoral and cell-mediated immunity. This finding is the first indication of a fundamental difference between neonatal and adult tolerance. The significance of these findings is discussed in the light of current immunological concepts and a hypothesis proposed to explain these phenomena.

Characterization of cross-reacting serotypes of Campylobacter jejuni

1989 ◽  
Vol 35 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Martin A. Preston ◽  
J. L. Penner
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Campylobacter Jejuni ◽  
Outer Membrane Protein ◽  
Antigenic Determinants ◽  
Protein Patterns ◽  
Cross Reactions ◽  
Antigenic Properties ◽  
Dna Restriction ◽  
Reference Strains

Some strains of Campylobacter jejuni react with more than one reference antiserum from the serotyping scheme based on heat-stable lipopolysaccharide antigens. To investigate the molecular basis of these cross-reactions, lipopolysaccharides from the reference strains for serotypes 4, 13, 16, 43, and 50 and isolates recovered during two different outbreaks of C. jejuni enteritis were analyzed by passive haemagglutination and sodium dodecyl sulphate – polyacrylamide gel electrophoresis coupled with silver staining or immunoblotting. The results showed that lipopolysaccharides from the reference strains and the isolates reacted with antisera prepared against heterologous strains in various combinations and that both silver-stainable, low Mr and non-silver-stainable, high Mr lipopolysaccharide components provided the antigenic determinants associated with the cross-reactions. There were strain-to-strain differences in the structural and antigenic properties of these macromolecules and shared antigenic determinants were not always provided by a common structure. Analysis of the silver-stained lipopolysaccharide profiles, outer membrane protein patterns, and chromosomal DNA restriction patterns indicated that strains with the same lipopolysaccharide profile could have the same outer membrane protein pattern and the same DNA restriction pattern. These results provided evidence for the presence of clones within this antigenic complex and implicated antigenic variation in some strains as the phenomenon responsible for the multiplicity of cross-reactions.Key words: Campylobacter, serotypes, cross-reaction.

scholarly journals Identification in human plasma of low M r protein fragments with antigenic determinants of kininogen

FEBS Letters ◽  
1982 ◽  
Vol 138 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Ulla Hamberg ◽  
Ann-Christine Syvänen ◽  
Sirkka Siimesmaa
Keyword(s):  
Human Plasma ◽  
Antigenic Determinants ◽  
Protein Fragments

scholarly journals The antigenicity of tobacco mosaic virus

1999 ◽  
Vol 354 (1383) ◽  
pp. 559-568 ◽  
Author(s):  
M. H. V. van Regenmortel
Keyword(s):  
Coat Protein ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Quaternary Structure ◽  
Antigenic Determinants ◽  
Bottom Surface ◽  
Protein Subunit ◽  
Segmental Mobility ◽  
Protein Subunits ◽  
Antigenic Properties

The antigenic properties of the tobacco mosaic virus (TMV) have been studied extensively for more than 50 years. Distinct antigenic determinants called neotopes and cryptotopes have been identified at the surface of intact virions and dissociated coat protein subunits, respectively, indicating that the quaternary structure of the virus influences the antigenic properties. A correlation has been found to exist between the location of seven to ten residue–long continuous epitopes in the TMV coat protein and the degree of segmental mobility along the polypeptide chain. Immunoelectron microscopy, using antibodies specific for the bottom surface of the protein subunit, showed that these antibodies reacted with both ends of the stacked disk aggregates of viral protein. This finding indicates that the stacked disks are bipolar and cannot be converted directly into helical viral rods as has been previously assumed. TMV epitopes have been mapped at the surface of coat protein subunits using biosensor technology. The ability of certain monoclonal antibodies to block the co–translational disassembly of virions during the infection process was found to be linked to the precise location of their complementary epitopes and not to their binding affinity. Such blocking antibodies, which act by sterically preventing the interaction between virions and ribosomes may, when expressed in plants, be useful for controlling virus infection.

scholarly journals Ultrastructural and Immunofluorescence Studies of the Cells Associated With µ-Chain Disease

Blood ◽  
1971 ◽  
Vol 37 (3) ◽  
pp. 257-271 ◽  
Author(s):  
DOROTHEA ZUCKER-FRANKLIN ◽  
EDWARD C. FRANKLIN
Keyword(s):  
Electron Microscopy ◽  
Secretory Pathway ◽  
Plasma Cells ◽  
Bone Marrow Cells ◽  
Light Chains ◽  
Antigenic Determinants ◽  
Protein Fragments ◽  
Fluorescence And Electron Microscopy ◽  
Golgi Zone ◽  
Heavy Chain Disease

Abstract Fluorescence and electron microscopy studies were carried out on the blood and bone marrow cells of the first patient observed to have µ-chain disease. Since previously reported cases of γ and α heavy-chain disease did not elaborate any light chains, it was of interest to determine whether both the µ-chain fragments and the κ chains found in the serum of this patient originated in the same cell or whether mutations had affected two different clones. The use of rhodamine-conjugated and fluorescein-conjugated antisera to heavy and light chains respectively established that both antigenic determinants were present in the same cell. On electron microscopy, the plasma cells showed large vacuoles which appeared to form in the vicinity of the Golgi zone and frequently extended to the surface of the cell. It is postulated that the structural defect in the µ chain interferes with proper assembly of the gamma-globulin molecule. This in turn may preclude transport via the normal secretory pathway. The accumulated protein fragments may be released by a process of limited cytolysis.

Sign in / Sign up

Export Citation Format

Share Document