Table of Contents
Journal of Allergy
Volume 2011 (2011), Article ID 839682, 11 pages
Review Article

Haptenation: Chemical Reactivity and Protein Binding

Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, MS L-2040, 1095 Willowdale Road, Morgantown, WV 26505, USA

Received 23 February 2011; Accepted 27 April 2011

Academic Editor: Gordon L. Sussman

Copyright © 2011 Itai Chipinda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Low molecular weight chemical (LMW) allergens are commonly referred to as haptens. Haptens must complex with proteins to be recognized by the immune system. The majority of occupationally related haptens are reactive, electrophilic chemicals, or are metabolized to reactive metabolites that form covalent bonds with nucleophilic centers on proteins. Nonelectrophilic protein binding may occur through disulfide exchange, coordinate covalent binding onto metal ions on metalloproteins or of metal allergens, themselves, to the major histocompatibility complex. Recent chemical reactivity kinetic studies suggest that the rate of protein binding is a major determinant of allergenic potency; however, electrophilic strength does not seem to predict the ability of a hapten to skew the response between Th1 and Th2. Modern proteomic mass spectrometry methods that allow detailed delineation of potential differences in protein binding sites may be valuable in predicting if a chemical will stimulate an immediate or delayed hypersensitivity. Chemical aspects related to both reactivity and protein-specific binding are discussed.