Protein quaternary structure and aggregation in relation to allergenicity

E.L. van Boxtel

Research output: Thesisinternal PhD, WUAcademic

Abstract

In order to induce systemic food allergic reactions in humans, proteins after digestion in the human gastro-intestinal tract should still be able to bind IgE. The aim of the work presented in this thesis was to determine the effects of heating on the structure and digestibility of cupin and prolamin food allergens from peanuts, Brazil nuts and soybeans and to determine the effects of digestion on the IgE binding capacity of these allergens. Representative allergen preparations were purified prior to the investigations. To this end, a large-scale purification method was developed for the purification of Brazil nut allergen Ber e 1, comprising its complete isoform pool. The denaturation temperature of the latter allergen at the common pH values of foods (5-7) appeared to be very high. As a result, this protein is assumed not to be denatured during common food processing and to be digested (mainly) in its native form. The native form of Ber e 1 is known to have a high stability towards peptic digestion, which likely explains the allergenicity of this protein. The representative quaternary structure of vicilin allergen Ara h 1 from peanuts appeared to be an oligomeric structure, in which the protein is assumed to interact with proanthocyanidins via a specific distribution of proline residues on its surface. Heat-induced aggregation prior to peptic hydrolysis under in vitro conditions did not affect the digestibility of Ara h 1, whereas heat-induced aggregation of legumin allergens Ara h 3 from peanuts and glycinin from soybeans (slightly) decreased the digestion rates. Regardless of pre-heating, the IgE binding capacity of the latter allergens diminished fast during pepsin digestion. As a result, in terms of systemic food allergic reactions, legumin allergens from peanuts and soybeans might not be very important allergens. Vicilin allergen Ara h 1 could still bind IgE after prolonged peptic digestion. Two pepsin-resistant epitopes were deduced and indications for four additional pepsin-resistant epitopes are presented. These epitopes are all situated on the unique N-terminal part of the allergen, which might explain why allergic reactions to peanuts are often severe, compared to other legume allergies.  
LanguageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Gruppen, Harry, Promotor
  • van den Broek, Ben, Co-promotor
  • Koppelman, S.J., Co-promotor, External person
Award date18 Dec 2007
Place of Publication[S.l.]
Publisher
Print ISBNs9789085047827
Publication statusPublished - 2007

Fingerprint

protein quaternary structure
allergenicity
allergens
digestion
peanuts
hypersensitivity
pepsin
Brazil nuts
epitopes
vicilin
legumin
heat
binding capacity
soybeans
digestibility
glycinin
purification methods
prolamins
proteins
protein structure

Keywords

  • allergens
  • proteins
  • denaturation
  • chemical structure
  • food allergies
  • soya protein
  • groundnut protein
  • Brazil nuts
  • protein digestion

Cite this

van Boxtel, E.L.. / Protein quaternary structure and aggregation in relation to allergenicity. [S.l.] : S.n., 2007. 152 p.
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title = "Protein quaternary structure and aggregation in relation to allergenicity",
abstract = "In order to induce systemic food allergic reactions in humans, proteins after digestion in the human gastro-intestinal tract should still be able to bind IgE. The aim of the work presented in this thesis was to determine the effects of heating on the structure and digestibility of cupin and prolamin food allergens from peanuts, Brazil nuts and soybeans and to determine the effects of digestion on the IgE binding capacity of these allergens. Representative allergen preparations were purified prior to the investigations. To this end, a large-scale purification method was developed for the purification of Brazil nut allergen Ber e 1, comprising its complete isoform pool. The denaturation temperature of the latter allergen at the common pH values of foods (5-7) appeared to be very high. As a result, this protein is assumed not to be denatured during common food processing and to be digested (mainly) in its native form. The native form of Ber e 1 is known to have a high stability towards peptic digestion, which likely explains the allergenicity of this protein. The representative quaternary structure of vicilin allergen Ara h 1 from peanuts appeared to be an oligomeric structure, in which the protein is assumed to interact with proanthocyanidins via a specific distribution of proline residues on its surface. Heat-induced aggregation prior to peptic hydrolysis under in vitro conditions did not affect the digestibility of Ara h 1, whereas heat-induced aggregation of legumin allergens Ara h 3 from peanuts and glycinin from soybeans (slightly) decreased the digestion rates. Regardless of pre-heating, the IgE binding capacity of the latter allergens diminished fast during pepsin digestion. As a result, in terms of systemic food allergic reactions, legumin allergens from peanuts and soybeans might not be very important allergens. Vicilin allergen Ara h 1 could still bind IgE after prolonged peptic digestion. Two pepsin-resistant epitopes were deduced and indications for four additional pepsin-resistant epitopes are presented. These epitopes are all situated on the unique N-terminal part of the allergen, which might explain why allergic reactions to peanuts are often severe, compared to other legume allergies.  ",
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van Boxtel, EL 2007, 'Protein quaternary structure and aggregation in relation to allergenicity', Doctor of Philosophy, Wageningen University, [S.l.].

Protein quaternary structure and aggregation in relation to allergenicity. / van Boxtel, E.L.

[S.l.] : S.n., 2007. 152 p.

Research output: Thesisinternal PhD, WUAcademic

TY - THES

T1 - Protein quaternary structure and aggregation in relation to allergenicity

AU - van Boxtel, E.L.

N1 - WU thesis, nr. 4347

PY - 2007

Y1 - 2007

N2 - In order to induce systemic food allergic reactions in humans, proteins after digestion in the human gastro-intestinal tract should still be able to bind IgE. The aim of the work presented in this thesis was to determine the effects of heating on the structure and digestibility of cupin and prolamin food allergens from peanuts, Brazil nuts and soybeans and to determine the effects of digestion on the IgE binding capacity of these allergens. Representative allergen preparations were purified prior to the investigations. To this end, a large-scale purification method was developed for the purification of Brazil nut allergen Ber e 1, comprising its complete isoform pool. The denaturation temperature of the latter allergen at the common pH values of foods (5-7) appeared to be very high. As a result, this protein is assumed not to be denatured during common food processing and to be digested (mainly) in its native form. The native form of Ber e 1 is known to have a high stability towards peptic digestion, which likely explains the allergenicity of this protein. The representative quaternary structure of vicilin allergen Ara h 1 from peanuts appeared to be an oligomeric structure, in which the protein is assumed to interact with proanthocyanidins via a specific distribution of proline residues on its surface. Heat-induced aggregation prior to peptic hydrolysis under in vitro conditions did not affect the digestibility of Ara h 1, whereas heat-induced aggregation of legumin allergens Ara h 3 from peanuts and glycinin from soybeans (slightly) decreased the digestion rates. Regardless of pre-heating, the IgE binding capacity of the latter allergens diminished fast during pepsin digestion. As a result, in terms of systemic food allergic reactions, legumin allergens from peanuts and soybeans might not be very important allergens. Vicilin allergen Ara h 1 could still bind IgE after prolonged peptic digestion. Two pepsin-resistant epitopes were deduced and indications for four additional pepsin-resistant epitopes are presented. These epitopes are all situated on the unique N-terminal part of the allergen, which might explain why allergic reactions to peanuts are often severe, compared to other legume allergies.  

AB - In order to induce systemic food allergic reactions in humans, proteins after digestion in the human gastro-intestinal tract should still be able to bind IgE. The aim of the work presented in this thesis was to determine the effects of heating on the structure and digestibility of cupin and prolamin food allergens from peanuts, Brazil nuts and soybeans and to determine the effects of digestion on the IgE binding capacity of these allergens. Representative allergen preparations were purified prior to the investigations. To this end, a large-scale purification method was developed for the purification of Brazil nut allergen Ber e 1, comprising its complete isoform pool. The denaturation temperature of the latter allergen at the common pH values of foods (5-7) appeared to be very high. As a result, this protein is assumed not to be denatured during common food processing and to be digested (mainly) in its native form. The native form of Ber e 1 is known to have a high stability towards peptic digestion, which likely explains the allergenicity of this protein. The representative quaternary structure of vicilin allergen Ara h 1 from peanuts appeared to be an oligomeric structure, in which the protein is assumed to interact with proanthocyanidins via a specific distribution of proline residues on its surface. Heat-induced aggregation prior to peptic hydrolysis under in vitro conditions did not affect the digestibility of Ara h 1, whereas heat-induced aggregation of legumin allergens Ara h 3 from peanuts and glycinin from soybeans (slightly) decreased the digestion rates. Regardless of pre-heating, the IgE binding capacity of the latter allergens diminished fast during pepsin digestion. As a result, in terms of systemic food allergic reactions, legumin allergens from peanuts and soybeans might not be very important allergens. Vicilin allergen Ara h 1 could still bind IgE after prolonged peptic digestion. Two pepsin-resistant epitopes were deduced and indications for four additional pepsin-resistant epitopes are presented. These epitopes are all situated on the unique N-terminal part of the allergen, which might explain why allergic reactions to peanuts are often severe, compared to other legume allergies.  

KW - allergenen

KW - eiwitten

KW - denaturatie

KW - chemische structuur

KW - voedselallergieën

KW - sojaeiwit

KW - aardnoteneiwit

KW - paranoten

KW - eiwitvertering

KW - allergens

KW - proteins

KW - denaturation

KW - chemical structure

KW - food allergies

KW - soya protein

KW - groundnut protein

KW - Brazil nuts

KW - protein digestion

M3 - internal PhD, WU

SN - 9789085047827

PB - S.n.

CY - [S.l.]

ER -