Raphaël Panzani

Ric c 1 and Ric c 3, the Allergenic 2S Albumin Storage Proteins of Ricinus communis: Complete Primary Structures and Phylogenetic Relationships

The 2S albumin storage protein of Ricinus communis consists of the two heterodimeric proteins Ric c 1 and Ric c 3 each of which is composed of a small and a large subunit linked together by disulphide bridges. The complete primary structures of both heterodimeric proteins were determined by enzymatic degradation and automated Edman degradation. The sequences of all four chains correspond to the known cDNA sequence of the gene of a presumed precursor molecule and to the previously determined partial sequences for Ric c 1 and Ric c 3. In addition, few differences in amino acid positions were found which seem to be related to different varieties of R. communis. Sequence comparisons with 2S albumin from other plant genera revealed high degrees of homology and support the view of a common genetic origin of this protein family. Ric c 1 and Ric c 3 which have 11,212 and 12,032 daltons, respectively, share a similar molecular size, biological function and allergenicity with the 2S albumins from Brassica juncea (Bra j 1E) and Sinapis alba L (Sin a 1). Ric c 1 and Ric c 3 may be classified as isoallergens if, additionally, the high degree of similarity in the position of polar residues is taken into account.

Allergy to green coffee: Failure of patients allergic to green coffee to react to chlorogenic acid, roasted coffee, or orange

Abstract Clinical skin tests upon twenty-nine French patients and allergic human serum transfer tests in monkeys indicate that primary allergy to green coffee does not involve chlorogenic acid or its known isomers. Allergy to green coffee appears to be a typical example of atopic hypersensitivity to proteins specific, in this allergy, to the green coffee bean. There were no cross-reactions to castor beans or oranges, nor were there any reaginic reactions to roasted coffee or to coffee beverage.

Vacuolar Serine Protease Is a Major Allergen of Cladosporium cladosporioides

Background:Cladosporium is an important allergenic fungus worldwide. We report here a major allergen of C. cladosporioides.Methods: Major C. cladosporioides allergens were characterized by immunoblotting, N-terminal amino acid sequencing, protein purification and cDNA cloning. Results: Seventy-four sera (38%) from 197 bronchial asthmatic patients demonstrated IgE binding against C. cladosporioides extracts. Among these 74 sera, 41 (55%) and 38 (51%) showed IgE binding against a 36- and a 20-kDa protein of C. cladosporioides, respectively. Both IgE-reacting components reacted with FUM20, a monoclonal antibody against fungal serine proteases. N-terminal amino acid sequencing results suggest that they are vacuolar serine proteases, and the 20-kDa component is possibly a degraded product of the 36-kDa allergen. A corresponding 5′-truncated 1,425-bp cDNA fragment was isolated. The mature protein after N-terminal processing starts with an N-terminal serine that is the ninth residue encoded by the 5′-truncated cDNA. The protein sequence deduced shares 69–72% sequence identity with Penicillium vacuolar serine proteases and was designated as Cla c 9. The purified 36-kDa Cla c 9 allergen showed proteolytic activity with peptide Z-Ala-Ala-Leu-pNA as substrate. IgE cross-reactivity was detected between the purified Cla c 9 and serine protease allergens from Aspergillusfumigatus and Penicillium chrysogenum.Conclusion: We identified a vacuolar serine protease as a major allergen of C. cladosporioides (Cla c 9) and a major pan-allergen of prevalent airborne fungi. IgE cross-reactivity among these highly conserved serine protease pan-fungal allergens was also detectable.

Nondiffusible allergenic contaminant isolated from samples of chlorogenic acid causing allergic reactions: Pure chlorogenic acid not an allergen

Abstract A sample of chlorogenic acid submitted by Sehon and Freedman as the allergen of green coffee was subjected to simple dialysis in cellophane bags. The diffusible low-molecular-weight component (dialysate) contained all of the chlorogenic acid of the original sample but was shown by Prausnitz-Kustner tests to be nonallergenic. The nondiffusible high-molecular-weight component retained within the dialysis bag contained no chlorogenic acid but did contain a coffee-specific antigen that caused positive skin reactions in Prausnitz-Kustner tests with sera from patients with atopy to green coffee. Samples of chlorogenic acid obtained from commerical sources contained nondiffusible antigen. A sample of synthetic chlorogenic acid from M. L. Scarpatis laboratory was found to be without allergenic activity in clinical tests upon French patients with severe allergy to green coffee. Nuclear magnetic resonance (NMR) spectra determined on all samples studied showed that all were correctly identified as chlorogenic acid (3-caffeoylquinic acid). These results together with our previous studies show that the coffee-specific allergenicity (antigenicity) present in some samples of chlorogenic acid is due entirely to protein present as a contaminant. It appears to be highly improbable that chlorogenic acid ever functions as an allergen in human atopic hypersensitivity to materials of plant origin.

Neutralization of Specific Reagins in Monkeys Passively Sensitized by Cross-Reactive Allergy Sera

Summary Blood sera from 60 allergy patients in Marseille, France, were examined by the reagin passive transfer test in macaque monkeys. Twenty-six of the sera were highly reactive with partially purified castor bean seed protein. Six of the reactive sera were also highly reactive with castor pollen extract. By utilization of the phenomenon of reagin neutralization (specific desensitization) with castor pollen extract, sites passively sensitized with these 6 sera were rendered non-reactive to the pollen allergens: the pollen-desensitized sites were still highly reactive to the seed protein. The results appear to support the conclusion that allergy to castor bean pomace may be hypersensitivity to one or more of several components of the seed, pollen, or female blossoms.