PMC:4996381 / 44127-45336 JSONTXT

{"project":"2_test","denotations":[{"id":"27600229-22464331-69479434","span":{"begin":1091,"end":1092},"obj":"22464331"}],"text":"Figure 1 Comparison of SPOT intensity differences following SPOT loading capacity reduction. Peptide arrays were prepared using a ratio of Fmoc-β-Alanine to Ac-β-Alanine that ranged from 1:0 to 1:10 in the first step of synthesis, effectively reducing the amount of peptide found on each SPOT of the array. (A) Binding of an His-tag® Antibody HPR conjugated (Novagen) to control peptides carrying 8 histidine residues (His8). Reduction of SPOT density did not show a dramatic difference in SPOT intensity, however SPOTs were much smaller and better defined as the SPOT loading was reduced. (B–F) Normalized SPOT intensity of histone H2A (B), H2B (C), H3 (D) and H4 (E,F) peptides bound to BRD4(1). Weaker peptides exhibited a drop in intensity as the SPOT density decreased, while non-specific peptides showed large variations. Interestingly, strongly binding peptides carrying 2 acetyl-lysine modifications (e.g., shown in F) exhibited overall a decrease in intensity when the SPOT loading was decreased and the binding was 1:1 (as previously determined by in solution binding studies in [3]), however this was not clear when the peptide:protein binding ratio was not 1:1, as in the case of H4K12ac/K16ac. "}