Grantee Research Project Results
2000 Progress Report: Conformational Protein Effects of Environmental Mutagens
EPA Grant Number: R826685Title: Conformational Protein Effects of Environmental Mutagens
Investigators: Brandt-Rauf, Paul
Institution: Columbia University in the City of New York
EPA Project Officer: Aja, Hayley
Project Period: October 1, 1998 through September 30, 2001
Project Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $388,644
RFA: Exploratory Research - Human Health (1998) RFA Text | Recipients Lists
Research Category: Human Health
Objective:
The objective of this research is to test the hypothesis that eight different environmentally induced mutations in the p53 tumor suppressor gene produce common conformational changes in the encoded p53 proteins. This is accomplished by conformational energy analysis and molecular dynamics simulations with confirmation by immunohistochemistry of tumor samples known to contain the given mutations using monoclonal antibodies for epitopes of the p53 protein coincident with predicted regions of common conformational change.Progress Summary:
Analysis of the first mutant structure had been completed during the first year of the project showing regions of common conformational change consistent with prior results with results of immunohistochemistry of conformationally altered epitopes. These results have been published.
In the second year of this study, we have been able to complete the calculations on all of the remaining seven p53 mutants, ahead of schedule. The output of RMS deviations of the mutant proteins in comparison to the wild-type protein for each of the amino acid residues clearly shows that the mutants have areas of common conformational changes. The specific nature of these changes in terms of the overall structure of the protein and the location of antibody epitopes remains to be studied. In addition, one of the regions of the mutant proteins that has been identified as undergoing common conformational changes has been investigated as a potential "effector domain." Based on prior experience with other prteins, such flexible regions are in many cases involved in critical interactions of the protein with other cellular elements through which the protein induces its functional effects. In this case, it has been possible to demonstrate through molecular dynamic modeling that this region probably interacts with another region of p53 and that both regions act as regulatory domains for the protein's apoptotic function. Peptides of one of these regions have been synthesized and shown to induce apoptosis of cancer cells in culture that contain p53 mutants (but not cells that contain wild-type p53) by disrupting the interaction between these regulatory domains. These results have also been published.
Future Activities:
The results of the molecular dynamics output for the remaining seven mutants will be analyzed in the next year to determine if they are structurally similar consistent with immunological analyses for epitopes. Further studies on the application of the conformational changes as biomarkers for the presence of mutant p53 based on the detection of common exposed epitopes in human populations to indicate environmentally induced mutations will be pursued. In addition, studies of p53 peptides from conformationally altered regions as inducers of restoration of normal p53 function will be continued.Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 5 publications | 5 publications in selected types | All 5 journal articles |
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Chen JM, Smith SJ, Marion M-J, Pincus MR, Brandt-Rauf PW. Common conformational effects in the p53 protein of vinyl chloride-induced mutations. Journal of Protein Chemistry 1999;18(4):467-472. |
R826685 (2000) R826685 (Final) |
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Kim AL, Raffo AJ, Brandt-Rauf PW, Pincus MR, Monaco R, Abarzua P, Fine RL. Conformational and molecular basis for induction of apoptosis by a p53 C-terminal peptide in human cancer cells. Journal of Biological Chemistry 1999;274(49):34924-34931. |
R826685 (2000) R826685 (Final) |
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Supplemental Keywords:
p53, tumor suppressor gene, protein, mutants, mutations, immunohistochemistry, antibodies., Health, RFA, Scientific Discipline, Health Risk Assessment, Risk Assessments, Disease & Cumulative Effects, cancer risk, carcinogens, health effects, immunohistochemistry, biological markers, environmental stressors, human exposure, molecular characterization, p53 tumor supressor gene, cancer risk assessment, cell biology, multi-pollutant analyses, indicators, environmentally induced mutations, conformational proteinProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.