Thermodynamic and kinetic analysis of peptides derived from CapZ, NDR, p53, HDM2, and HDM4 binding to human S100B.
S100B is a member of the S100 subfamily of EF-hand proteins that has been implicated in malignant melanoma and neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease. Calcium-induced conformational changes expose a hydrophobic binding cleft, facilitating interactions with a wide variety of nuclear, cytoplasmic, and extracellular target proteins. Previously, peptides derived from CapZ, p53, NDR, HDM2, and HDM4 have been shown to interact with S100B in a calcium-dependent manner. However, the thermodynamic and kinetic basis of these interactions remains largely unknown. To gain further insight, we screened these peptides against the S100B protein using isothermal titration calorimetry and nuclear magnetic resonance. All peptides were found to have binding affinities in the low micromolar to nanomolar range. Binding-induced changes in the line shapes of S100B backbone (1)H and (15)N resonances were monitored to obtain the dissociation constants and the kinetic binding parameters. The large microscopic K(on) rate constants observed in this study (≥1 × 10(7) M(-1) s(-1)) suggest that S100B utilizes a "fly casting mechanism" in the recognition of these peptide targets.
Center for Biotechnology and Interdisciplinary Studies and Department of Biology, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.
Lucas N
LN
Wafer
Werner W
WW
Streicher
Scott A
SA
McCallum
George I
GI
Makhatadze
D000595:Amino Acid Sequence; D051347:CapZ Actin Capping Protein / Q000737:chemistry / Q000378:metabolism; D018797:Cell Cycle Proteins; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2 / Q000737:chemistry / Q000378:metabolism; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000737:chemistry / Q000378:metabolism*; D013816:Thermodynamics; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism
D051347:CapZ Actin Capping Protein; D018797:Cell Cycle Proteins; C482775:MDM4 protein, human; D009414:Nerve Growth Factors; D009687:Nuclear Proteins; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; D017346:Protein Serine-Threonine Kinases