Title: Effect of d-amino acids on IgE binding to peanut allergens Authors
Submitted to: Journal of Allergy Clinical Immunology
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2013
Publication Date: March 4, 2013
Citation: Chung, S., Reed, S.S. 2013. Effect of d-amino acids on IgE binding to peanut allergens. Journal of Allergy Clinical Immunology. Vol 131, Issue 2, Supplement, 2013 - AB20. Technical Abstract: D-amino acids are formed when L-amino acids are exposed to heat. The objective was to determine the existence of D-amino acids in roasted peanut and their effect on IgE binding. Raw and roasted peanut protein extracts were hydrolyzed in 6 N HCL under vacuum. The hydrolysates were then analyzed for D- and L-amino acids using a reversed phase HPLC. For IgE-binding analyses, mixtures of commercial D-amino acids were each incubated with a pooled plasma from peanut-allergic patients in a plate coated with a peanut extract, and then probed with a monoclonal anti-human IgE HRP and color substrate. HPLC analyses indicated that of the D-amino acids known, only D-glutamic acid (Glu) and D-aspartic acid (Asp) were detected in peanuts. Roasted peanuts did not differ from raw in L/D ratio (Glu or Asp). ELISA data indicated that D-Asp and D-Glu in combination at 4 mg/mL inhibited IgE binding. D-Asp or D-Glu alone had little effect. Other D- or L-amino acids had no effect. The D form in combination appeared to exhibit a stronger inhibition effect than the L form. D-Glu and D-Asp were detected, but were not different in ratio between raw and roasted peanuts. Both amino acids (4 mg/mL) in combination, but not others, synergistically inhibited IgE binding to peanut allergens. D form appeared to have a stronger inhibition effect than the L form.