Isolation and Partial Characterization of Allergen C from Kentucky Blue Grass Pollen

Abstract

An allergenic component, designated as Allergen C, was isolated from the retentate (R) of the aqueous extract of defatted Kentucky blue grass (KBG) pollen by a combination of preparative isoelectrofocussing and gel filtration. Allergen C was found to be a glycoprotein with molecular size of the order of 11,000 daltons and had a pI value of ∼9.7. It possessed all the allergenic determinants collectively present in R. The allergenic activity was found to be associated with the protein moiety of the molecule. Allergen C was one of the 15 antigenic components detectable in R by crossed immunoelectrophoresis with a hyperimmune sheep antiserum to R. Observations based on enzymatic degradation of the molecule suggested that the determinants recognized by murine IgE antibodies were different from those which combined with rabbit precipitating antibodies.

Isolation of Allergenically Active Cytochrome c from Kentucky Blue Grass Pollen

“…An analysis of aller genic relationships between the two glyco protein allergens and KBG-cytochrome c may aid in the understanding of the role of carbohydrate (if any) on the allergenicity of the two glycoprotein allergens. It should be noted that the color, size and charge charac teristics of cytochrome c closely resembled that of allergen C [2] and one may therefore contend that cytochrome c might be con taminated with allergen C. Although such a possibility cannot be completely ruled out, the following observations would suggest that allergen C, if at all present in KBG-cy tochrome c, it would be in trace amounts.…”

“…In earlier studies from our laboratory, protocols were developed for isolating puri fied allergens from the aqueous extract of KBG pollen [1,2,[10][11][12]. In the present study, we report the isolation of an allergenically active cytochrome c from the nondialysable multicomponent fraction, i.e.…”

“…Since asparagine and glut amine in a protein are converted into glut amic and aspartic acids, respectively, dur ing acid hydrolysis, the amounts of aspartic and glutamic acid determined by the acid hydrolysis of KBG-cytochrome c may in deed be higher than their actual values. To obtain the true values, it will be necessary to identify the individual amino acids in the course of the complete sequence analysis of KBG-cytochrome c. A striking difference noted between KBG-cytochrome c and two glycoprotein allergens, C-I-2-6 [11] and al lergen C [2] also isolated from KBG pollen, was that the cytochrome c allergen was de void of carbohydrate. An analysis of aller genic relationships between the two glyco protein allergens and KBG-cytochrome c may aid in the understanding of the role of carbohydrate (if any) on the allergenicity of the two glycoprotein allergens.…”

Physicochemical and immunochemical characterization of allergenic proteins from rye-grass (Lolium perenne) pollen prepared by a rapid and efficient purification method

“…Bound IgE was detected with 125I-labelled rabbit anti-human IgE, raised against the YU IgE myeloma, purified and iodinated as described by Johansson et al (1971). Assay methodology used and calculations of the results have been described in detail by Gleich et al (1974) and Chakrabarty et al (1981).…”

“…Preparative i.e.f. using either polyacrylamide gels or granulated gel beds now offers the potential of preparing components of high quality in good yield (Topping et al, 1978;Ekramaddoullah et al, 1981;Chakrabarty et al, 1981).…”