During the last 3 years, (i) high yields (>30 mg purified protein/liter media) of S 100B, S 100A 1, S 100A3, CAN19, mtsl, p53, p53(324-393), p53(303-393), p53(303-367), hepatitis B viral protein X (HBVX), SUMO-1, C-terminal fragment of myosin IIA(1900-1961), and the HMG A box of the high mobility group protein- 1 (HMG-1) were prepared in minimal media as necessary for isotopic labeling (2H, 13C, 15N, etc). (ii) We determined the solution structures of apo-S 100B, apo-S 100A 1, calcium-bound S 100B, and calcium-bound S 100B in a complex with the negative regulatory domain of p53 (residues 367-388). (iii) We showed that dimeric S 100B is the physiologically relevant oligomerization state of S 100B, and that S 100B inhibits protein kinase C (PKC) phosphorylation of p53. (iv) We developed cellular-based assays for p53 and showed that p53 function is inhibited in tumor cell lines as a result of the calcium-dependent p53-S 100B interaction. This interaction includes both the oligomerization and negative regulatory domains at the C-terminus of p53. We plan to continue characterizing the calcium-dependent interaction of S 100B with the tumor suppressor protein p53. The effects that p53 phosphorylation, acetylation, and sumoylation have on S 100B binding will be examined. The binding of zinc to S 100B and heterodimer formation (i.e. S 100A 1/S 100B, CaN 19/S 100B and mts 1/S 100B etc.) will also be characterized. These data are necessary to determine whether covalent modifications of p53 and/or other S100B binding events affect S100B-p53 complex formation and function We will also determine the 3D structure of calcium-bound S100B complexed with a larger construct of p53 that includes both the oligomerization and the C-terminal regulatory domains of p53 (residues 324-393; Kd=24nM). Heteronuclear relaxation measurements for backbone and sidechain resonances are planned for all of the structures that we solve (or have solved) in order to clarify how calcium and p53 binding affects the dynamics of S100B (and p53). These dynamic data will be used in a search for small molecule inhibitors of the S 100B-p53 interaction. Lastly, the 3D solution structures of other proteins that bind the C-terminus of p53 will be examined including the metastasis protein 1 (mts 1), S100A3, the CaN 19 tumor suppressor, the hepatitis B viral protein (HBVX), the p53 binding domain of BLM, and the A box ofHMG-1. It will be interesting to determine whether these or other p53-binding proteins enhance and/or compete with the S 100B-p53 interaction. ? ? ?

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-SSS-B (01))
Program Officer
Wehrle, Janna P
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Maryland Baltimore
Schools of Medicine
United States
Zip Code
Melville, Zephan; Aligholizadeh, Ehson; McKnight, Laura E et al. (2017) X-ray crystal structure of human calcium-bound S100A1. Acta Crystallogr F Struct Biol Commun 73:215-221
Melville, Zephan; Hernández-Ochoa, Erick O; Pratt, Stephen J P et al. (2017) The Activation of Protein Kinase A by the Calcium-Binding Protein S100A1 Is Independent of Cyclic AMP. Biochemistry 56:2328-2337
Cavalier, Michael C; Melville, Zephan; Aligholizadeh, Ehson et al. (2016) Novel protein-inhibitor interactions in site 3 of Ca(2+)-bound S100B as discovered by X-ray crystallography. Acta Crystallogr D Struct Biol 72:753-60
Roth, Braden M; Varney, Kristen M; Rustandi, Richard R et al. (2016) (1)H(N), (13)C, and (15)N resonance assignments of the CDTb-interacting domain (CDTaBID) from the Clostridium difficile binary toxin catalytic component (CDTa, residues 1-221). Biomol NMR Assign 10:335-9
Cavalier, Michael C; Ansari, Mohd Imran; Pierce, Adam D et al. (2016) Small Molecule Inhibitors of Ca(2+)-S100B Reveal Two Protein Conformations. J Med Chem 59:592-608
Bresnick, Anne R; Weber, David J; Zimmer, Danna B (2015) S100 proteins in cancer. Nat Rev Cancer 15:96-109
Hartman, Kira G; Vitolo, Michele I; Pierce, Adam D et al. (2014) Complex formation between S100B protein and the p90 ribosomal S6 kinase (RSK) in malignant melanoma is calcium-dependent and inhibits extracellular signal-regulated kinase (ERK)-mediated phosphorylation of RSK. J Biol Chem 289:12886-95
Dhar, Amlanjyoti; Mallick, Shampa; Ghosh, Piya et al. (2014) Simultaneous inhibition of key growth pathways in melanoma cells and tumor regression by a designed bidentate constrained helical peptide. Biopolymers 102:344-58
Cavalier, Michael C; Pierce, Adam D; Wilder, Paul T et al. (2014) Covalent small molecule inhibitors of Ca(2+)-bound S100B. Biochemistry 53:6628-40
Hartman, Kira G; McKnight, Laura E; Liriano, Melissa A et al. (2013) The evolution of S100B inhibitors for the treatment of malignant melanoma. Future Med Chem 5:97-109

Showing the most recent 10 out of 64 publications