What is Kd for the interaction between HIF and the core of p53? HIF is another protein which can bind to p53 at the central domain- or location which p53 binds to DNA (See Figure 2 on page 1 of the exam). Increased anisotropy indicates that a piece of fluorescently-tagged protein (HIF) is bound to the p53 protein. (increased anisotropy = increased binding). (Snchez-Puig, et al Mol. Cell 2005. (17):11-21.) This anisotropy data was used to construct the Hill Plot which is the insert to the Graph C. 0.2 0.18 0.16 Anisotropy 0.14 log (Bound/Free) 0.5 0.12 -1.5 0.1 -8.5 8.6 -7.5 log p53 core) 0.08 0 5 10 1 107 1.5 107 2 107 [p53corel (M)