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C Capiau

Publications and source records attributed to C Capiau.

32 records · Page 2Linked to original sources
PubMed1991

Development of an acellular pertussis vaccine and its administration as a booster in healthy adults.

An acellular pertussis vaccine which contains highly purified pertussis toxoid (PT) and filamentous haemagglutinin (FHA) has been developed. These proteins have been shown to be stable, with essentially no significant reversion of the pertussis toxoid after a new detoxification procedure. Two clinical trials using this vaccine as a booster in 45 healthy adults have been performed. Results show that the vaccine was well tolerated, causing essentially mild, transient symptoms after administration. It induced an increase in anti-PT and anti-FHA antibody titres in all vaccinees.

Adult↗
PubMed1991

The cell mediated and humoral immune response to vaccination with acellular and whole cell pertussis vaccine in adult humans.

The cell mediated immune response (CMI) against pertussis antigens following vaccination with the traditional Danish whole cell pertussis vaccine (WC-P) and the Japanese acellular pertussis vaccine (A-PV) JNIH-3 was studied in four adult human volunteers. Vaccination with the A-PV induced an in vitro proliferative response of peripheral blood lymphocytes to pertussis toxin (PT) subunits S2-S4, S3-S4 and S5 and the filamentous hemagglutinin (FHA), and a better serological response to native PT, detoxified PT (dPT) and FHA than the WC-PV. The induced CMI and serological response were followed over a period of 17 weeks, and were not seen to decline during this period. Further, an in vitro proliferative response to Bordetella pertussis agglutinogen 2 and 3 were demonstrated using lymphocytes from recently and not-so-recently pertussis-vaccinated adults.

Adhesins, Bacterial↗
PubMed1990

Genetic characterization of Bordetella pertussis filamentous haemagglutinin: a protein processed from an unusually large precursor.

The nucleotide sequence of the structural gene for filamentous haemagglutinin (FHA), fhaB, a crucial adherence factor for Bordetella pertussis, has been determined. Its 10774 nucleotides are far more than necessary to encode the 220 kD biologically active, mature polypeptide product, suggesting a role for co- or post-translational processing. Fusion proteins derived from various portions of the fhaB open reading frame (ORF) were used to generate polyclonal antisera. Western immunoblot analysis of purified FHA and Bordetella sp. whole cell extracts with these antisera indicated that the 220 kD product is encoded by the 5' portion of the ORF and that the smaller polypeptide species are breakdown products of this polypeptide. These data, as well as N-terminal amino acid sequencing of the major polypeptide species, suggest a scheme for the proteolytic processing of an FHA precursor polypeptide.

Adhesins, Bacterial↗
PubMed1989

Identification of amino acid residues essential for the enzymatic activities of pertussis toxin.

The enzymatic ADP-ribosyltransferase activity associated with the S1 subunit of pertussis toxin is considered to be responsible for its biological effects. Although pertussis toxin has no significant homology to other ADP-ribosylating toxins such as diphtheria toxin and Pseudomonas aeruginosa exotoxin A, the results presented in this paper show that, as for diphtheria toxin and exotoxin A, tryptophan and glutamic acid residues are essential for the enzymatic activities of pertussis toxin. Moreover, a structural motif can be identified around the critical glutamic acid residue. Chemical modification or site-directed deletion or replacement of Trp-26 abolishes ADP-ribosyltransferase and the associated NAD glycohydrolase activities. Both enzymatic activities are also abolished when Glu-129 is deleted or replaced by aspartic acid. Mutations at the Glu-106 position do not significantly reduce the enzymatic activities of the S1 subunit. The mutations do not affect the ability of the different S1 forms to be recognized by a variety of monoclonal antibodies, including neutralizing antibodies. Pertussis toxin containing a deletion or replacement of Trp-26, Glu-129, or both in the S1 subunit should thus be devoid of toxic activities without losing its reactivity with protective antibodies and, therefore, could be safely included in new generation vaccines against whooping cough.

2-Hydroxy-5-nitrobenzyl Bromide↗
PubMed1988

Structural characterization of recombinant hepatitis B surface antigen protein by mass spectrometry.

The primary structure of recombinant hepatitis B surface antigen protein produced in yeast has been confirmed by mass spectrometric peptide mapping. These studies corroborate more than 85% of the amino acid sequence derived by sequencing of the gene and identified the presence of an acetyl moiety on approximately 70% of the NH2-terminal methionine residues. Prior to the present work, direct structural analysis was largely prevented by the insolubility of this integral membrane protein and its primary degradation fragments in aqueous buffers and by partial blockage of the NH2 terminus. These difficulties were overcome by preparative isolation using electroelution of the monomeric 226 amino acid protein from a polyacrylamide electrophoretic gel in the presence of sodium dodecyl sulfate. Chymotryptic digestion of the reduced and carboxymethylated monomer produced a large number of small, predominantly hydrophobic peptides ideally suited for peptide mapping by fast atom bombardment mass spectrometry. The percentage of NH2-terminal methionine blocked by acetyl was determined by a new strategy involving cyanogen bromide cleavage, permethylation, and gas chromatography/mass spectrometry identification and quantitation of the N-methyl-N-acetylhomoserine produced.

Amino Acid Sequence↗
PubMed1987

Development of a hepatitis B vaccine from transformed yeast cells.

The production in yeast cells of the recombinant DNA hepatitis B vaccine of SmithKline Biologicals involves an optimized fermentation process followed by cell disruption and extraction, together with other soluble yeast components of the surface antigen of the hepatitis B virus. The subsequent purification process includes precipitation steps, ion exchange and gel permeation chromatography, and caesium chloride ultracentrifugation. The yeast-derived antigen occurs as spherical particles containing the non-glycosylated HBsAg polypeptide, lipid, and Tween 20. The purity of the polypeptide is above 95% and confirmed by the absence of an immune response to yeast-derived contaminants in vaccinees. Yeast DNA levels were less than 10 pg/vaccine dose. Various biochemical analyses showed that the recombinant polypeptide was faithfully expressed and did not undergo unwanted processing or degradation during fermentation or purification. These results indicate that the recombinant HBsAg can be effectively produced in yeast and processed to a high degree of purity to yield HBsAg particles displaying most of the characteristic properties of plasma-derived HBsAg.

Amino Acid Sequence↗
PubMed1986

Protein-chemical analysis of pertussis toxin reveals homology between the subunits S2 and S3, between S1 and the A chains of enterotoxins of Vibrio cholerae and Escherichia coli and identifies S2 as the haptoglobin-binding subunit.

The purified toxin of Bordetella pertussis was dissociated in 5 M urea in the presence of immobilized haptoglobin. The toxin was dissociated in free S1, free S5 and the free complexes S2-S4 and S3-S4, with S2-S4 as the only haptoglobin-binding moiety, identifying S2 as the haptoglobin-binding protein. Partial NH2-terminal amino acid sequences were obtained from the dissimilar toxin subunits, after separation by SDS-polyacrylamide gel electrophoresis followed by electroblotting onto polybrene-coated glass-fiber sheets. The sequences reveal extensive homology of the N-terminal portions of the constitutive subunits S2 and S3 and between S1 and the enterotoxin A chains of Vibrio cholerae and Escherichia coli.

Amino Acid Sequence↗
PubMed1985

The complete amino acid sequence of diphtheria toxin fragment B. Correlation with its lipid-binding properties.

The complete amino acid sequence of fragment B from diphtheria toxin has been determined. The polypeptide chain was split with cyanogen bromide, o-iodosobenzoic acid, clostripain and trypsin; all amino acid sequence analyses were made by automated Edman degradation. Fragment B, which corresponds to the carboxy terminus of the toxin molecule, contains 342 amino acids and has an Mr of 37240. The proposed amino acid sequence fully confirms the structure recently deduced from the nucleotide sequence of the structural gene. The complete sequence is analyzed in relationship with the role of fragment B in the transfer of diphtheria toxin fragment A from the extracellular medium into the cell cytoplasm.

Amino Acid Sequence↗
PubMed1982

Structure-activity relationships of the B fragment of diphtheria toxin: the lipid-binding domains.

Two different lipid-associating domains have previously been identified in diphtheria toxin fragment B: one of the surface type in the N-terminus of B and one of the transverse type in its middle region. We have now determined about 85% of the primary structure of fragment B and show, here, that the middle part of fragment B contains a highly hydrophobic region of 72 amino acid residues (polarity index: 295) which includes the transverse lipid-associating domain. That this domain is actually involved in a process of membrane penetration is suggested by lipid bilayer conductance measurements of the CNBr peptides of fragment B and trypsin treatment of fragment B-multilamellar liposome complexes.

Amino Acid Sequence↗
PubMed1980

Primary structure of diphtheria toxin fragment B: structural similarities with lipid-binding domains.

Two different lipid-associating domains have been identified in the B fragment of diphtheria toxin using automated Edman degradation of its cyanogen bromide peptides, secondary structure prediction analysis, and comparisons with known phospholipid-interacting proteins. The first domain is located in the highly hydrophilic (polarity index [PI] = 61.0%) 9.00-dalton N-terminal region of fragment B. This region shows primary and predicted secondary structures dramatically similar to those found for the phospholipid headgroup-binding domains of human apolipoprotein A1 (surface lipid-associating domain). The second domain is located in the highly hydrophobic (PI = 32.4%) middle region of fragment B. Its structure resembles that found for the membranous domain of intrinsic membrane proteins (transverse lipid-associating domain). In contrast, the hydrophilic C-terminal 8,000-dalton region of fragment B (PI = 53.8%) does not show structural similarity with lipid-associating domains.

Amino Acid Sequence↗