Epi p 1, an allergenic glycoprotein of Epicoccum purpurascens is a serine protease.
Epicoccum purpurascens (EP) is a ubiquitous saprophytic mould, the inhalant spores and mycelia of which are responsible for respiratory allergic disorders in 5-7% of population worldwide. The diagnosis/therapy of these disorders caused by fungi involves the use of standardized and purified fungal extracts. A 33.5 kDa glycoprotein, Epi p 1 released histamine from whole blood cells of EP allergic patients at a concentration of 50-ng protein. The high specific IgE values detected in EP hypersensitive sera indicated that Epi p 1 is capable of mediating type I hypersensitive reaction in predisposed individuals. It also showed protease activity by virtue of its dose dependent cleavage of serine protease specific synthetic substrate, N-benzoyl arginine ethyl ester hydrochloride (BAEE). The serine protease nature of Epi p 1 was confirmed by its N-terminal sequence (ADG/FIVAVELD/STY) homology to a subtilisin like serine protease. The protease activity of Epi p 1 may be responsible for making its way into the system of pre-disposed individuals through epithelial cell detachment and the histamine releasing ability by cross-linking of IgE antibodies on cell surface is the cause of its allergenic nature.
Bisht
Vandana
V
Institute of Genomics and Integrative Biology, Mall Road, DU Campus, Delhi 7, India. vanbisht@hotmail.com
Arora
Naveen
N
Singh
Bhanu Pratap
BP
Pasha
Santosh
S
Gaur
Shailendra Nath
SN
Sridhara
Susheela
S
D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001203:Ascomycota / Q000201:enzymology* / Q000276:immunology; D005656:Fungal Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D012130:Respiratory Hypersensitivity / Q000209:etiology* / Q000276:immunology; D012697:Serine Endopeptidases / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification
D000485:Allergens; D052179:Antigens, Plant; D005656:Fungal Proteins; D007073:Immunoglobulin E; C494359:Epi p 1 allergen, Epicoccum purpurascens; D012697:Serine Endopeptidases