Mathematical Model And Application Research Of P53Tumorres-suppsor Gene

The p53is a gene that codes for a protein that regulates the cell cycle and hence functions as a tumor suppressor. It is very important in maintaining genetic stability and regulating the cell cycle. However, when the wild p53mutates, it can change the normal gene, whether human or animal, into the cancer gene.The main contents are listed as follows:1. In order to study between anticodon different positions of the bases of p53mutations in Head and Neck Cancer and the physical and chemical properties of amino acids. The algebraic structure of oncogene was established, in this paper the Euclidean distance named d was defined on the basic of the algebraic structure. And the Euclidean distance was weighted by using improved variation coefficient method. Got a new weighted Euclidean distance d*.The p53mutations in head and neck cancer was analyzed by using d and d*.The method based on the d*can judge which bases of the p53mutation codon had been changed more obviously. When d is more than1.5, the second base has been changed, and it shows that the physical and chemical properties of amino acids has also been changed. When d is less than1.2, the first or the third base has been changed, but it can’t change the physical and chemical properties of amino acids. The result shows that the second base has the biggest influence of amino codon, the first has small influence, and the third has almost no impact in the physical and chemical properties of amino acids.2. In order to study human p53tumor protein further, seven latest human p53tumor protein mRNA sequences were selected from GenBank, and their codon bias was analyzed. The relative usage degree of the synonymous codon (RSCU) was obtained by using MEGA4.0software. In order to explain this seven mRNA sequence’s synonymous codon bias practicability, the QRSCU of the synonymous codon was calculated. The homology of the seven mRNA sequences reached above99.9%, and their protein sequences’homology reached above99.1%. By analyzing and comparing, the method based on the classification of Quasi-amino acid showed its synonymous codon consistent bias more obviously. P53mutated genes preference use codons ending with c/g, and the result is certain significance to the research of its cancerous genes and cancer genes.3. In order to study human p53tumor protein further, twenty-six human TP53, TP63and TP73mRNA sequences were analyzed. By using fuzzy comprehensive evaluation and establishing membership functions, codons ending with different bases(a,c,g,u(t)) having effect on the hydrophobicity of amino acids of human p53, p63and p73tumor proteins was explored. The result shows that the codon ending with c has the greatest influence on the hydrophobicity of amino acids in human Tp53, Tp63and Tp73mRNA sequences, the codon ending with u(t) has the greater influence, the codon ending with g has ordinary influence and the codon ending with a has the weakest influence.The innovations are listed as follows:1. Work out the weights by using the improved variation coefficient method.2. Define the Weighted Euclidean distance between the two condons.3. By analyzing and comparing, the method based on the classification of Quasi-amino acid showed its synonymous codon consistent bias more obviously. 4. Using fuzzy comprehensive evaluation method combined with the selected p53gene sequence established the characteristics of the subordinate function, p53and their family members to analysis.