Molecular cloning and immunological characterisation of Cyn d 7, a novel calcium‐binding allergen from Bermuda grass pollen¹

Characterization and Immunolocalization of a Cytosolic Calcium-Binding Protein from Brassica napus and Arabidopsis Pollen1

“…This linkage is highly conserved among diverse species. In addition to the Brassica proteins, highly related pollen allergens have been identified in Betula verrucosa (Engel et al, 1997;Twardosz et al, 1997), Olea europaea (Batanero et al, 1997), Artemisia vulgaris (Engel et al, 1997), and the monocots Cynodon dactylon (Suphioglu et al, 1997), Phleum pratens, and Lilium longiflorum (Engel et al, 1997;Twardosz et al, 1997). The present study also describes cloning of APC1, a homolog from Arabidopsis, and demonstrates the presence of related sequences in Antirrhinum but not in tobacco (Nicotiana tabacum).…”

“…In the presence of calcium, rBPC1 may assume a more compact conformation than in the apo state, enabling it to elute as a smaller protein. Conformational changes in response to calcium have been demonstrated in related proteins (Engel et al, 1997;Suphioglu et al, 1997;Twardosz et al, 1997). Second, it is possible that rBPC1 may interconvert between a monomeric and dimeric state in response to calcium.…”

“…The presence of multiple forms of the protein coincides with our DNA-blot data revealing a small gene family in B. napus, an amphidiploid derived from B. rapa and B. oleracea. Betula verrucosa and C. dactylon have also been shown to have at least two versions of the protein (Knox et al, 1992;Suphioglu et al, 1997;Twardosz et al, 1997). Two hybridizing DNA sequences were also detected in Arabidopsis, suggesting the presence of a second gene related to APC1.…”

“…Immunolocalization of some BPC1 in the pollen walls was observed after hydration and germination, suggesting that leakage of the protein from the cytosol to the wall occurred as the grains hydrated. In addition, BPC1-related proteins have been characterized as human allergens (Knox et al, 1992;Toriyama et al, 1995;Batenero et al, 1997;Engel et al, 1997;Suphioglu et al, 1997;Twardosz et al, 1997), as have the BET vIII and BET vI pollen proteins, which have 2-to 2.5-fold greater molecular masses than BPC1 (Vrtala et al, 1993;Seiberler et al, 1994). This allergenicity implies a pollen-surface location or release upon pollen hydration.…”

Solution Structure, Dynamics, and Hydrodynamics of the Calcium-bound Cross-reactive Birch Pollen Allergen Bet v 4 Reveal a Canonical Monomeric Two EF-Hand Assembly with a Regulatory Function

“…10,11 A series of allergenic polcalcins have been reported in the literature, namely Aln g 4 from alder (Alnus glutinosa), 12 Ole e 3 from olive (Olea europaea), 13,14 Syr v 3 from lilac (Syringa vulgaris; Ledesma et al, unpublished), Bra n 1 or BPC1 and Bra n 2 from oilseed rape (Brassica napus) as well as Bra r 1 and Bra r 2 from turnip rape (Brassica rapa), 15 -18 Phl p 7 from timothy grass (Phleum pratense), 19 and Cyn d 7 from Bermuda grass (Cynodon dactylon). 20,21 Aln g 4, Syr v 3, Bra n 1 or BPC1, Bra n 2, Bra r 1, Bra r 2 and Phl p 7 as well as the polcalcin APC1 from mouse-ear cress (Arabidopsis thaliana), 18 however, have not been included in the official allergen list of the International Union of Immunological Societies (IUIS) yet and the allergen designations Bra n 1 and Bra r 2 even conflict with two unrelated allergens. 22 These polcalcins share more than 65% sequence identity with Bet v 4 ( Figure 1) and due to their widespread distribution over the plant kingdom and their high IgE cross-reactivity 10 -13,17,19 -21 they might constitute so-called panallergens.…”