References of "Dumoulin, Mireille"
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See detailHereditary systemic amyloidosis associated with mutational variants of human lysozyme
Dumoulin, Mireille ULg; Bellotti, Vittorio; Dobson, Christopher

in Sipe, J. (Ed.) In Amyloid Proteins: The Beta Pleated Sheet Conformation and Disease (2005)

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See detailProbing the origins, diagnosis and treatment of amyloid diseases using antibodies.
Dumoulin, Mireille ULg; Dobson, Christopher

in Biochimie (2004), 86

The deposition of proteins in the form of amyloid fibrils is the characteristic feature of more than 20 medical conditions affecting the central nervous system or a variety of peripheral tissues. These ... [more ▼]

The deposition of proteins in the form of amyloid fibrils is the characteristic feature of more than 20 medical conditions affecting the central nervous system or a variety of peripheral tissues. These disorders, which include Alzheimer's disease, the prion diseases and type II diabetes, are of enormous importance in the context of present-day human health and welfare. Extensive research is therefore being carried out to define the molecular details of the mechanism of the pathological conversion of amyloidogenic proteins from their soluble forms into fibrillar structures. This review focuses on recent studies that demonstrate the power of using antibodies or antibody fragments to probe the process of fibril formation, and discusses the emerging potential of these species as diagnostic and therapeutic agents. [less ▲]

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See detailA camelid antibody fragment inhibits the formation of amyloid fibrils by human lysozyme
Dumoulin, Mireille ULg; Last, A. M.; Desmyter, A. et al

in Nature (2003), 424(6950), 783-788

Amyloid diseases are characterized by an aberrant assembly of a specific protein or protein fragment into fibrils and plaques that are deposited in various organs and tissues(1-3), often with serious ... [more ▼]

Amyloid diseases are characterized by an aberrant assembly of a specific protein or protein fragment into fibrils and plaques that are deposited in various organs and tissues(1-3), often with serious pathological consequences. Non-neuropathic systemic amyloidosis (4-6) is associated with single point mutations in the gene coding for human lysozyme. Here we report that a single-domain fragment of a camelid antibody(7-9) raised against wild-type human lysozyme inhibits the in vitro aggregation of its amyloidogenic variant, D67H. Our structural studies reveal that the epitope includes neither the site of mutation nor most residues in the region of the protein structure that is destabilized by the mutation. Instead, the binding of the antibody fragment achieves its effect by restoring the structural cooperativity characteristic of the wild-type protein. This appears to occur at least in part through the transmission of long-range conformational effects to the interface between the two structural domains of the protein. Thus, reducing the ability of an amyloidogenic protein to form partly unfolded species can be an effective method of preventing its aggregation, suggesting approaches to the rational design of therapeutic agents directed against protein deposition diseases. [less ▲]

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See detailIn vitro stability and immunoreactivity of the native and recombinant plant food 2S albumins Ber e 1 and SFA-8
Murtagh, M.; Archer, D.; Dumoulin, Mireille ULg et al

in Clinical & Experimental Allergy : Journal of the British Society for Allergy & Clinical Immunology (2003), 8

Background The ability of an intact protein to reach the circulatory system may be a prerequisite to allergenicity and many allergens, particularly those from plant foods, have been found to be ... [more ▼]

Background The ability of an intact protein to reach the circulatory system may be a prerequisite to allergenicity and many allergens, particularly those from plant foods, have been found to be consistently more resistant to digestion by pepsin than other proteins. Objective This study assessed the pepsinolytic stability of native 2S albumins from Brazil nut and sunflower seed and their recombinant versions produced in Pichia pastoris. The physicochemical stability of native and recombinant Brazil nut 2S albumins and recombinant sunflower seed 2S albumin was also assessed. The immunoreactivity of native Brazil nut 2S albumin and recombinant 2S albumins was compared using serum from patients allergic to Brazil nuts and animals immunized with native 2S albumins. Methods Digestibility was measured in simulated gastric fluid followed by SDS-PAGE. Circular dichroism spectra were used to analyse unfolding, as proteins were denatured by temperature, pH and guanidinium chloride. Immunoreactivity was assessed by immunoblot, RAST and ELISA. Results Brazil nut 2S albumin was significantly more resistant to proteolytic digestion than other Brazil nut proteins. It was also resistant to thermally and chemically induced denaturation. Equally high resistance to proteolytic digestion was observed with sunflower seed 2S albumin. The recombinant albumins mirrored their native counterparts in stability and immunoreactivity. Conclusion The important food allergen Brazil nut 2S albumin is as stable to digestion as is sunflower seed 2S albumin, whose allergenicity has yet to be determined. The 2S albumins and their recombinant counterparts could not be easily denatured by physicochemical treatments. The results suggest that 2S albumin is the only Brazil nut protein to reach the gut immune system intact. The production of properly folded recombinant proteins will facilitate mechanistic studies as well as diagnostic testing and antigen-based therapies. [less ▲]

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See detailSingle-domain antibody fragments with high conformational stability.
Dumoulin, Mireille ULg; Conrath, Katja; Van Meirhaeghe, Annemie et al

in Protein Science : A Publication of the Protein Society (2002), 11(3), 500-15

A variety of techniques, including high-pressure unfolding monitored by Fourier transform infrared spectroscopy, fluorescence, circular dichroism, and surface plasmon resonance spectroscopy, have been ... [more ▼]

A variety of techniques, including high-pressure unfolding monitored by Fourier transform infrared spectroscopy, fluorescence, circular dichroism, and surface plasmon resonance spectroscopy, have been used to investigate the equilibrium folding properties of six single-domain antigen binders derived from camelid heavy-chain antibodies with specificities for lysozymes, beta-lactamases, and a dye (RR6). Various denaturing conditions (guanidinium chloride, urea, temperature, and pressure) provided complementary and independent methods for characterizing the stability and unfolding properties of the antibody fragments. With all binders, complete recovery of the biological activity after renaturation demonstrates that chemical-induced unfolding is fully reversible. Furthermore, denaturation experiments followed by optical spectroscopic methods and affinity measurements indicate that the antibody fragments are unfolded cooperatively in a single transition. Thus, unfolding/refolding equilibrium proceeds via a simple two-state mechanism (N <--> U), where only the native and the denatured states are significantly populated. Thermally-induced denaturation, however, is not completely reversible, and the partial loss of binding capacity might be due, at least in part, to incorrect refolding of the long loops (CDRs), which are responsible for antigen recognition. Most interestingly, all the fragments are rather resistant to heat-induced denaturation (apparent T(m) = 60-80 degrees C), and display high conformational stabilities (DeltaG(H(2)O) = 30-60 kJ mole(-1)). Such high thermodynamic stability has never been reported for any functional conventional antibody fragment, even when engineered antigen binders are considered. Hence, the reduced size, improved solubility, and higher stability of the camelid heavy-chain antibody fragments are of special interest for biotechnological and medical applications. [less ▲]

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See detailStability of recombinant 2 S albumin allergens in vitro
Murtagh, Gareth; Dumoulin, Mireille ULg; Alcocer, Marcos et al

in Biochemical Society Transactions (2002), 30

Two well known 2 S albumins, Ber e 1 from brazil nut and sunflower 2 S albumin 8 (SFA-8), have been expressed in a eukaryotic system and purified. Analysis of recombinant versions of Ber e 1 and SFA-8 ... [more ▼]

Two well known 2 S albumins, Ber e 1 from brazil nut and sunflower 2 S albumin 8 (SFA-8), have been expressed in a eukaryotic system and purified. Analysis of recombinant versions of Ber e 1 and SFA-8 revealed them to be significantly more resistant to digestion by pepsin than BSA, and to be stable for up to 30 min in simulated gastric fluid. Unfolding monitored by CD indicated that both proteins were also very resistant to denaturation induced by heat and low pH. These results suggest that, although the ability of 2 S albumins to reach the circulatory system may be a prerequisite for the allergenicity of this group of proteins, stability is just one of a number of characteristics that provoke a selective immune response. [less ▲]

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See detailThe Disulphide Mapping, Folding and Characterisation of Recombinant Ber e 1, an Allergenic Protein, and SFA8, Two Sulphur-rich 2 S Plant Albumins
Alcocer, Marcos; Murtagh, G. J.; Bailey, Kevin et al

in Journal of Molecular Biology (2002), 324

We have cloned and expressed genes encoding the allergenic brazil nut 2 S albumin (Ber e 1) and the sunflower albumin 8 (SFA8) in the methylotrophic yeast Pichia pastoris. We show that both proteins were ... [more ▼]

We have cloned and expressed genes encoding the allergenic brazil nut 2 S albumin (Ber e 1) and the sunflower albumin 8 (SFA8) in the methylotrophic yeast Pichia pastoris. We show that both proteins were secreted at high levels and that the purified proteins were properly folded. We also showed that Ber e 1 is glycosylated during secretion and that the glycan does not interfere with the folding or immunoreactivity. The disulphide map of the Ber e 1 protein was experimentally established and is in agreement with the conserved disulphide structure of other members of the 2 S albumin family. A model three-dimensional structure of the allergen was generated. During the expression studies and through mutation we have also shown that alteration of the sequences around the Kex2 endoproteolytic processing site in the expressed fusion protein can compromise the secretion by targeting part of the protein for possible degradation. The secreted production of these properly folded sulphurrich plant albumins presents an opportunity to delineate the attributes that make an allergen and to facilitate the diagnosis and therapy of type I allergy. [less ▲]

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See detailContribution of the carbohydrate moiety to conformational stability of the carboxypeptidase Y high pressure study.
Dumoulin, Mireille ULg; Ueno, H.; Hayashi, R. et al

in European Journal of Biochemistry (1999), 262(2), 475-83

The process of pressure-induced denaturation of carboxypeptidase Y and the role of the carbohydrate moiety in its response to pressure and low temperature were investigated by measuring in situ the ... [more ▼]

The process of pressure-induced denaturation of carboxypeptidase Y and the role of the carbohydrate moiety in its response to pressure and low temperature were investigated by measuring in situ the catalytic activity and, the intrinsic and 8-anilino-1-naphthalene sulfonic acid binding fluorescences. Pressure-induced denaturation of carboxypeptidase Y is a process involving at least three transitions. Low pressures (below 150 MPa) induced slight conformational changes characterized by a slight decrease in the center of the spectral mass of intrinsic fluorescence, whereas no changes in 8-anilino-1-naphthalene sulfonic acid binding fluorescence were observed and 80% of the catalytic activity remained. Higher pressure (150-500 MPa) induced further conformational changes, characterized by a large decrease in the center of the spectral mass of intrinsic fluorescence, a large increase in the 8-anilino-1-naphthalene sulfonic acid binding fluorescence and the loss of all catalytic activity. Thus, this intermediate exhibited characteristics of molten globule-like state. A further increase, in pressure (above 550 MPa) induced transition from this first molten globule-like state to a second molten globule-like state. This two-stage denaturation process can be explained by assuming the existence of two independent structural domains in the carboxypeptidase molecule. A similar three-transition process was found for unglycosylated carboxypeptidase Y, but, the first two transitions clearly occurred at lower pressures than those for glycosylated carboxypeptidase Y. These findings indicate that the carbohydrate moiety protects carboxypeptidase Y against pressure-induced denaturation. The origin of the protective effects is discussed based on the known crystallographic structure of CPY. [less ▲]

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See detailContribution of the carbohydrate moiety to conformational stability of the carboxypeptidase Y high pressure study.
Dumoulin, Mireille ULg; Ueno, H.; Hayashi, R. et al

in European Journal of Biochemistry (1999), 262(2), 475-83

The process of pressure-induced denaturation of carboxypeptidase Y and the role of the carbohydrate moiety in its response to pressure and low temperature were investigated by measuring in situ the ... [more ▼]

The process of pressure-induced denaturation of carboxypeptidase Y and the role of the carbohydrate moiety in its response to pressure and low temperature were investigated by measuring in situ the catalytic activity and, the intrinsic and 8-anilino-1-naphthalene sulfonic acid binding fluorescences. Pressure-induced denaturation of carboxypeptidase Y is a process involving at least three transitions. Low pressures (below 150 MPa) induced slight conformational changes characterized by a slight decrease in the center of the spectral mass of intrinsic fluorescence, whereas no changes in 8-anilino-1-naphthalene sulfonic acid binding fluorescence were observed and 80% of the catalytic activity remained. Higher pressure (150-500 MPa) induced further conformational changes, characterized by a large decrease in the center of the spectral mass of intrinsic fluorescence, a large increase in the 8-anilino-1-naphthalene sulfonic acid binding fluorescence and the loss of all catalytic activity. Thus, this intermediate exhibited characteristics of molten globule-like state. A further increase, in pressure (above 550 MPa) induced transition from this first molten globule-like state to a second molten globule-like state. This two-stage denaturation process can be explained by assuming the existence of two independent structural domains in the carboxypeptidase molecule. A similar three-transition process was found for unglycosylated carboxypeptidase Y, but, the first two transitions clearly occurred at lower pressures than those for glycosylated carboxypeptidase Y. These findings indicate that the carbohydrate moiety protects carboxypeptidase Y against pressure-induced denaturation. The origin of the protective effects is discussed based on the known crystallographic structure of CPY. [less ▲]

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See detailTextural properties of pressure-induced gels of food proteins obtained under different temperatures including zero
Dumoulin, Mireille ULg; Osawa, S.; Hayashi, Rikimaru

in Journal of Food Science (1998), 63

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See detailHigh presure: a unique tool for pressurisation
Dumoulin, Mireille ULg; Hayashi, Rikimaru

in Food Science & Technology International (1998), 4

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See detailTextural properties of pressure-induced gels of food proteins obtained under different temperatures
Dumoulin, Mireille ULg; Ozawa, S.; Hayashi, Rikimaru

in Heremans, Karel (Ed.) High Pressure Research in Biosciences and Biotechnology (1997)

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See detailTextural properties of pressure-induced gels of food proteins obtained under different temperatures
Dumoulin, Mireille ULg; Ozawa, S.; Hayashi, Rikimaru

in Suzuki, Atsushi; Hayashi, Rikimaru (Eds.) High Pressure Bioscience and Technology (1997)

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