Haptomer
A haptomer is a molecule or part of a molecule that is responsible for binding to the cell membrane of a target cell in larger molecules or molecular complexes . A mostly toxic effectomer can be bound to the haptomer as a further component . The binding of a haptomer to the cell membrane of the target cell thus enables the effectomer to develop its effect.
The terms haptomer and effectomer are used in particular for lectins and other toxic proteins in order to distinguish the cell-binding from the toxic part.
| Protein / protein complex | Haptomer | Effectomer | Specificity of the haptomer |
|---|---|---|---|
| Abrin | B subunit | A subunit | Mannose receptor |
| Cholera toxin | B subunits | A subunit | Gangliosides |
| Diphtheria toxin | B subunit | A subunit | |
| Ricin | B subunit | A subunit | Galactose-β1-4-N-acetylgalactosamine-β1 residues, mannose receptor |
| Shiga toxin | B subunits | A subunit | Globotriaosylceramide |
literature
- Pei-Show Juo: Concise Dictionary of Biomedicine and Molecular Biology , 2nd edition, CRC Press, 2010, ISBN 1420041304 .