While it appears that Oto and Wnt3a bind directly, other linking proteins or binding partners may be present at low concentrations, and although we think it unlikely, it is possible that minor residual disulfide bridges and/or protein denaturation may contribute to the observed Oto/Wnt association.
If these conditions are met, it can be concluded that detergent treatment can cause conformational changes in the protein and binding sites may be present on the protein.
Hydrogen peroxide is known to promote peptide bond cleavage (Stadtman and Levine 2003), so an additional ferrous ion binding site may be present in ACCO that produces hydrogen peroxide in the presence of Asc and oxygen in a Fenton-type reaction.
Multiple zinc finger (ZF) domains, each capable of binding to dsRNA, may be present in dsRBZFPs; for example, the dsRNA-binding zinc finger protein a (ZFa) contains seven dsRNA-binding zinc finger domains.
At the same time, it is unknown whether LDL-CIC contain only modified LDL, or also native LDL; the last is possible due to common immunoglobulin-binding sites, which may be present in both native and modified LDL.
Imbalance between testosterone and estrogen is caused by some kinds of sex hormone-binding globulin, which may be present in hyperthyroidism, chronic liver diseases and the use of medications, such as spironolactone.
However, enhancers with H3K4me1 and/or P300 occupancy are not always active [ 3, 11], since H3K4me1 precedes enhancer-binding factors and P300 may be present in poised and intermediate enhancer states [ 36].
In addition, specific DnaA-binding sequences for each bacterium may be present in close proximity to oriC.
Also, the evolution of binding sites is not strictly qualitative: a site may be present, but with a changed binding rate.
