Possesses beta-1,3-endoglucanase activity in vitro (PubMed:25700348). Is thought to be an important plant defense-related product against fungal pathogens (Probable). Hydrolysis of (1->3)-beta-D-glucosidic linkages in (1->3)-beta-D-glucans. Optimum pH is 4.5-5.0. The enzyme from cv. GT.1 displays a second optimum pH at 6.7. Monomer. Expressed at highest levels in laticifer cells of the petiole. Glycosylated in cv. GT.1 and cv. RRIM 600 but not in cv. PR 261. Asn-350 is glycosylated only in cv. GT.1 due to the presence of Ser-352. In cv. PR 261 and cv. RRIM 600, Ser-352 is replaced by Gly so Asn-350 is not glycosylated. In cv. GT.1, four different forms of the enzyme have been detected with differently processed C-termini. In cv. PR 261 and cv. RRIM 600, only 2 forms are detected, a major form which is processed at residue 352 and a minor form which is processed at residue 354. The enzyme from cv. GT.1 displays a 3-5 fold lower specific activity than the enzyme from cv. PR 261. Causes an allergic reaction in human (PubMed:25700348). Binds to IgE of patients allergic to rubber latex (PubMed:25700348). Binds to IgE of patients allergic to fruits (PubMed:25700348). Associated to the latex-fruit syndrome, an hypersensitivity to latex developed by individuals who are allergic to consumed fruits (Probable). Belongs to the glycosyl hydrolase 17 family.