Production and characterization of a noncytotoxic deletion variant of the Aspergillus fumigatus allergen Aspf1 displaying reduced IgE binding.
Aspergillus fumigatus is responsible for many allergic respiratory diseases, the most notable of which - due to its severity - is allergic bronchopulmonary aspergillosis. Aspf1 is a major allergen of this fungus: this 149-amino acid protein belongs to the ribotoxin family, whose best characterized member is alpha-sarcin (EC 3.1.27.10). The proteins of this group are cytotoxic ribonucleases that degrade a unique bond in ribosomal RNA impairing protein biosynthesis. Aspf1 and its deletion mutant Aspf1Delta(7-22) have been produced as recombinant proteins; the deleted region corresponds to an exposed beta-hairpin. The conformation of these two proteins has been studied by CD and fluorescence spectroscopy. Their enzymatic activity and cytotoxicity against human rhabdomyosarcoma cells was also measured and their allergenic properties have been studied by using 58 individual sera of patients sensitized to Aspergillus. Aspf1Delta(7-22) lacks cytotoxicity and shows a remarkably reduced IgE reactivity. From these studies it can be concluded that the deleted beta-hairpin is involved in ribosome recognition and is a significant allergenic region.
Garciá-Ortega
Lucía
L
Departamento de Bioquímica y Biología Molecular I, Facultad de Química, Universidad Complutense, Madrid, Spain.
Lacadena
Javier
J
Villalba
Mayte
M
Rodríguez
Rosalía
R
Crespo
Jesús F
JF
Rodríguez
Julia
J
Pascual
Cristina
C
Olmo
Nieves
N
Oñaderra
Mercedes
M
del Pozo
Alvaro Martínez
AM
Gavilanes
José G
JG
D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001232:Aspergillus fumigatus / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D004722:Endoribonucleases / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011500:Protein Synthesis Inhibitors / Q000737:chemistry / Q000276:immunology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment
C081947:ASPF1 protein, Aspergillus fumigatus; D000485:Allergens; D052179:Antigens, Plant; D005656:Fungal Proteins; D011500:Protein Synthesis Inhibitors; D011994:Recombinant Proteins; C014801:alpha-sarcin; D007073:Immunoglobulin E; D004722:Endoribonucleases