Purification of the major group 1 allergen from Bahia grass pollen, Pas n 1.
BACKGROUND
Group 1 grass pollen allergens are glycoproteins of the β-expansin family. They are a predominant component of pollen and are potent allergens with a high frequency of serum IgE reactivity in grass pollen-allergic patients. Bahia grass is distinct from temperate grasses and has a prolonged pollination period and wide distribution in warmer climates. Here we describe the purification of the group 1 pollen allergen, Pas n 1, from Bahia grass (Paspalum notatum), an important subtropical aeroallergen source.


METHODS
Pas n 1 was purified from an aqueous Bahia grass pollen extract by ammonium sulphate precipitation, hydrophobic interaction and size exclusion chromatography, and assessed by one- and two-dimensional gel electrophoresis, immunoblotting and ELISA.


RESULTS
Pas n 1 was purified to a single 29-kDa protein band containing two dominant isoforms detected by an allergen-specific monoclonal antibody and serum IgE of a Bahia grass pollen-allergic donor. The frequency of serum IgE reactivity with purified Pas n 1 in 51 Bahia grass pollen-allergic patients was 90.6%. Serum IgE reactivity with purified Pas n 1 was highly correlated with serum IgE reactivity with Bahia grass pollen extract and recombinant Pas n 1 (r = 0.821 and 0.913, respectively).


CONCLUSIONS
Pas n 1 is a major allergen reactive at high frequency with serum IgE of Bahia grass pollen-allergic patients. Purified natural Pas n 1 has utility for improved specific diagnosis and immunotherapy for Bahia grass pollen allergy.
Cooperative Research Centre for Asthma and Airways, Sydney, N.S.W., Australia.
Alexander C
AC
Drew
Janet M
JM
Davies
Thanh D
TD
Dang
Jennifer M
JM
Rolland
Robyn E
RE
O'Hehir
D000485:Allergens / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D052179:Antigens, Plant / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D031781:Paspalum / Q000737:chemistry / Q000276:immunology*; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D011058:Pollen / Q000737:chemistry* / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; D007073:Immunoglobulin E