InterPro domain: IPR034088

This entry includes pollen allergen Pla a 1 protein from Platanus acerifolia (London plane tree) and its homologues, including pectinesterase inhibitor 12 from Arabidopsis [ 1 ].

The major Platanus acerifolia pollen allergen Pla a 1 belongs to a class of allergens related to proteinaceous invertase and pectin methylesterase inhibitors. Platanus acerifolia is an important cause of pollinosis; Pla a 1 has a prevalence of about 80% among plane tree pollen-allergic patients [ 2 ]. Recombinant Pla a 1 binds IgE in vitro, similar to its natural counterpart, rendering it suitable for specific diagnosis and structural studies [ 3 ].

Invertase inhibitors are structurally similar to those of pectin methylesterase (PMEIs), an enzyme that is involved in the control of pectin metabolism and is structurally unrelated to invertases [ 4 ]. All inhibitors share a size of about 18kDa, two strictly conserved disulfide bridges and only moderate sequence homology (about 20% sequence identity) [ 5 ].

1. Three pectin methyl esterase inhibitors protect cell wall integrity for immunity to Botrytis. Plant Physiol.
2. Purification and characterization of Pla a 1, a major allergen from Platanus acerifolia pollen. Allergy 57, 221-7
3. The major Platanus acerifolia pollen allergen Pla a 1 has sequence homology to invertase inhibitors. Clin. Exp. Allergy 33, 978-85
4. The plant invertase inhibitor shares structural properties and disulfide bridges arrangement with the pectin methylesterase inhibitor. J. Protein Chem. 22, 363-9
5. Multiple crystal forms of the cell-wall invertase inhibitor from tobacco support high conformational rigidity over a broad pH range. Acta Crystallogr. D Biol. Crystallogr. 62, 665-70