Table 1: Different PR-protein families and allergens identified.

FamilyProteinsFunctionsAllergens identified with source and allergenic symptoms

PR-1PR-1 a, PR-1 b, and PR-1 cAntifungalCuc m 3 (muskmelon)—oral allergy syndrome
PR-2β-1,3-GlucanasesCleaves β-1,3-glucansHev b 2 (latex)—contact dermatitis
Ole e 9 (olive)—respiratory allergy
Mus a 5 (banana)—oral allergy syndrome
PR-3Chitinase types I, II, IV, V, VI, and VIIEndochitinasePers a 1 (avocado)—itchy eyes or nose, asthma, swelling, and so forth.
Mus a 2 (banana)—food allergy like swelling of lips, anaphylaxis, and so forth
PR-4Chitinase types I and IIAntifungal and chitinaseHev b 6.01, Hev b 6.02, and Hev b 6.03 (latex)—contact dermatitis
PR-5Thaumatin-like proteinsAntifungalJun a 3 (mountain cedar), Cry j 1 (Japanese cedar), and Cup a 3 (Arizona cypress)—rhinitis, conjunctivitis, and asthma
Pru av 2 (cherry), Mal d 2 (apple), Cap a 1 (bell pepper), Act d 2 (kiwi), and Mus a 4 (banana)—oral allergy syndrome
PR-6Tomato proteinase inhibitor I Proteinase inhibitor
PR-7Tomato endoproteinase P Endoproteinase
PR-8Cucumber chitinaseChitinase IIIHevamine (latex)—contact dermatitis.
Ziz m 1 (Indian jujube)—oral allergy syndrome
Cof a 1 (coffee)—eye and airway allergy
PR-9Tobacco lignin-forming peroxidase Peroxidase
PR-10Parsley “PR-1”
Bet v 1, Mal  d  1, Api g 1, and Dau c 1
Ribonuclease-likeBet v 1 (birch pollen)— allergic rhinoconjunctivitis and asthma
Pru av 1 (cherry), Mal  d  1 (apple), Api g 1 (celery), and Dau c 1 (carrot)—oral allergy syndrome
Gly m 4 (soy), Vig r 1 (mung bean), Cor a 1 (hazelnut), and Cas s 1 (chestnut)—oral allergy syndrome
PR-11Tobacco chitinase type VChitinase
PR-12Radish Rs-AFP3Defensin
PR-13Arabidopsis THI2.1Thionin
PR-14Lipid transfer proteinsShuttling of phospholipids and fatty acids Par j 1 (weed)—rhinitis and asthma
Pru p 3 (peach), Mal d 3 (apple), Pru av 3 (cherry), Pru ar 3 (apricot), Cor a 8 (hazelnut), Cas s 8 (chestnut), and Zea m 14 (maize)—oral allergy syndrome
PR-15Barley OxOa Oxalate oxidase
PR-16Barley OxOLPOxalate-like oxidase
PR-17Tobacco PRp27 Unknown