To overcome this limitation, we developed HDXMEM, a novel NMR method, and elucidated three clinically relevant IgE-binding epitopes of the mugwort pollen allergen Art v 3. Recombinant Art v 3 was used to immunize mice for subsequent generation of mAbs. NMR approach termed hydrogen/deuterium exchange memory space (HDXMEM). It relies on the slow exchange between the invisible antigen-mAb complex and the free15N-labeled antigen whose1H-15N correlations are recognized. Due to a memory effect, changes of NH safety during antibody binding are measured. Variations in H/D exchange rates and analyses of mAb reactivity to homologous LTPs exposed three structural epitopes: two partially cross-reactive areas around -helices 2 and 4 as well as a novel Art v 3specific epitope in the Pronase E Pronase E C terminus. Protein variants with exchanged epitope residues confirmed the antibody-binding sites and Pronase E exposed strongly reduced IgE reactivity. Using the novel HDXMEM for NMR epitope mapping allowed recognition of the 1st structural epitopes of an allergenic pollen LTP. This knowledge enables improved cross-reactivity prediction for individuals suffering from LTP allergy and facilitates design of therapeutics. Keywords:allergen, monoclonal antibody, epitope mapping, NMR spectroscopy, lipid transfer protein, hydrogen/deuterium exchange, Art v 3, mugwort pollen, allergen, epitope mapping, nuclear magnetic resonance (NMR), immunoglobulin E (IgE), immunoglobulin G (IgG) Connection of antibodies with their antigen-binding sites (epitopes) is vital to maintain health but may also contribute to immunological diseases. To understand these interactions, dedication of binding specificities and exact epitope localization is definitely a crucial but not trivial task (1). A reliable technique to investigate binding of an antigen with its respective antibody is definitely X-ray crystallography. This, however, typically requires production and extensive screening of truncated antibody fragments that need to generate high-quality (co-)crystals (2,3). More recently, MS-based approaches possess used hydrogen/deuterium exchange to reveal binding areas (4,5). Variations Pronase E in exchange rates can be measured in the peptide mass level, but resolution is typically poor, because it mostly depends on the convenience of proteolytic cleavage sites. Another optioni.e.testing of immobilized synthetic peptides covering the entire antigen sequence is straightforward but limited to analysis of continuous, linear epitopes (6,7). A powerful technique for mapping protein interactions is definitely NMR spectroscopy using chemical shift deviations (8). However, the large molecular size of the mAb-antigen complexes prevents a straightforward software. Analogous to X-ray crystallography, so far Fab fragments of the mAbs acquired by enzymatic cleavage are a standard prerequisite for analyses (9). However, Fab fragments often display low stability, and although the size of the Fab-antigen complex is still large and demanding for NMR measurements, it was successful in several instances. Typically, additional deuteration of the protein and unique NMR techniques like TROSY experiments are required (10). Whereas this strategy seems successful for NMR epitope mapping (1116), it relies on the availability of isolated Fab fragments and works best with relationships under a fast-exchange program. Whereas fragile relationships typically having a fast-exchange program can be well-analyzed, limited relationships with lowkoffrates are demanding. Moderately tight relationships involving large proteins can be analyzed by cross-saturation experiments like chemical exchange saturation transfer or dark-state exchange saturation transfer as long as right now there is sufficient exchange during the NMR experiment, ideally with exchange time scales between 10 ms and 1 s (17,18). However, these methods rely on exchange between the free and the bound form, and they fail if thekoffrates are much slower than a scan of the NMR experiment. For relationships with antibodies, deuteration of the15N-labeled binding partner mainly improves the overall performance (16). Another strategy for limited relationships involves weakening of affinitye.g.by the use of detergents (15). However, such improvements might influence the results, as the collapse and stability of the antibody and antigen can be affected. NMR-detected H/D exchange has also been utilized for connection mapping with antibodies, either based on directly observable fragments (19,20) or on a tedious protocol including quenching the H/D exchange, separating the antigen from your mAb FLJ13165 and detecting the amount of NH in spectra of the separated antigen for each time point (20,21). Considering all described applications, we currently lack a straightforward, high-resolution method for dedication of structural epitopes of antigens interacting very tightly with undamaged antibodies under native conditions. Id of antibody-binding epitopes must research IgE cross-reactivity Pronase E effectively, design book vaccines, and monitor allergen immunotherapies (22). At the moment, a lot more than 100 tertiary buildings of allergens have already been resolved, but information on the antibody-binding epitopes is quite limited (23). This also pertains to non-specific lipid transfer protein (LTPs) which were identified as.