A smaller promiscuous biotin ligase for proximity biotinylation called BioID2 enables more-selective targeting of fusion proteins, requires less biotin supplementation, exhibits enhanced labeling of proximate proteins, and demonstrates the use of a flexible linker to modulate the biotin-labeling radius.

The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

The potential epitope of a recombinant food allergen protein, cashew Ana o 1, reactive to monoclonal antibody, mAb 2G4, has been mapped by solution-phase amide backbone H/D exchange (HDX) monitored by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Purified mAb 2G4 was incubated with recombinant Ana o 1 (rAna o 1) to form antigen:monoclonal antibody (Ag:mAb) complexes. Complexed and uncomplexed (free) rAna o 1 were then subjected to HDX-MS analysis. Five regions protected from H/D exchange upon mAb binding are identified as potential conformational epitope-contributing segments.

There are a number of examples of immunologic cross-reactivity elicited by pollens, fruits, seeds, and nuts of closely related plant species. Such cross-reactivity is of particular concern for patients with food allergies. In this report, we investigated a spice (mahleb) that is prepared from the kernel of the St. Lucie cherry, Prunus mahaleb, for cross-reactivity with almond (Prunus dulcis), using enzyme-linked immunosorbent assay (ELISA) and Western blot. Almond and mahleb are members of the same genus. Cross-reactivity between the mahleb and almond was demonstrated by reaction of cherry and almond kernel protein extracts with antibodies raised against almond proteins. Almond-specific murine monoclonal IgG, rabbit polyclonal IgG, and almond-allergic serum IgE each exhibited cross-reactivity with cherry kernel protein. Because of the demonstrated cross-reactivity between almond and mahleb, these findings should be of special concern to almond-allergic patients and attending medical personnel.