Related Experiment Video
Updated: Jul 16, 2026

Harvesting Venom Toxins from Assassin Bugs and Other Heteropteran Insects
Published on: April 21, 2018
Natural and recombinant enzymatically active or inactive bee venom phospholipase A2 has the same potency to release
E Förster1, T Dudler, M Gmachl
1Pediatric and First Department of Dermatology, University of Vienna, Austria.
Background:
A complementary DNA encoding the major bee venom allergen phospholipase A2 (PLA) has been characterized recently. Recombinant PLA was produced in Escherichia coli and purified to apparent homogeneity. Natural PLA was compared with recombinant PLA in its ability to release histamine from blood basophils.
Methods:
A synthetic gene encoding the mature form of PLA was expressed in E. coli, and the polypeptide was purified to homogeneity by affinity chromatography and refolded, yielding fully enzymatically active PLA. In addition, we have produced a genetically engineered enzymatically inactive variant by substitution of a single amino acid residue in the catalytic center. A standard histamine release assay was used to compare the potency of natural PLA with correctly folded enzymatically active and inactive recombinant PLA to release histamine from blood basophils of nine patients with bee venom allergy.
Results:
Recombinant enzymatically active PLA and purified natural protein were equally effective in releasing histamine from sensitized basophils. By comparing the histamine-releasing capacity of enzymatically active and inactive recombinant allergen, we further demonstrate that catalytic activity is not a requirement for allergenicity in the effector phase. Denaturation of natural PLA or incorrect folding of recombinant protein resulted in a total loss of allergenic potency.
Conclusion:
We demonstrate the feasibility of producing native-like recombinant allergens with or without enzymatic activity. We also provide evidence for the requirement of correct three-dimensional structure of PLA to induce histamine release from basophils and thus evidence for its recognition by IgE.
Related Concept Videos
Allergic Reactions
Allergic Drug Reactions
Adrenergic Agonists: Direct-Acting Agents
These agents can be classified...
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Allergic Reactions: Anaphylaxis

