Hydrolysis of (1->3)-beta-D-glucosidic linkages in (1->3)-beta-D-glucans. Optimum pH is 4.5-6.0. Homodimer. Expressed only in pollen. The N-terminal region (1-350) contains the enzymatic activity while the C-terminal region (360-460) can bind laminarin. Both regions are allergenic by themselves. Glycosylated. Contains two additional disulfide bonds, but it is unclear if they are between the pairs Cys-392-Cys-398 and Cys-407-Cys-453 (PudMed:18096638) or between the pairs Cys-392-Cys-453 and Cys-398-Cys-407 (PudMed:12392450). Causes an allergic reaction in human. Major allergen from olive pollen. Important in Mediterranean countries. Belongs to the glycosyl hydrolase 17 family. The sequences determined for the two internal peptides of Ole e 4 are identical to internal fragments of Ole e 9. However, the apparent molecular weight of the two proteins is different and they are still classified as two separate allergens (PubMed:22385802), even though we may be facing two different isoforms of the same allergen.