Study Of Death Domain Fold Proteins

The research on the protein is pioneering and interdisciplinary in the area of life science. The protein is a kind of biological macromolecular polymer, a main substance to keep life's movement. At the same time, protein molecules play all kinds of biological functions in organism, for instance, biological reaction catalyzing, nutritional matter transportation, signal recognition and transferability. It is all known that apoptosis is an important characteristic of growth modulation in cellulous organism and it is a stepwise and active process of autogenetic death in cell, play an important role in process of disease happening. On the other hand death domain fold proteins are absolutely necessary in apoptosis, the importance of this protein is went without saying. We shall study death domain fold proteins in this thesis.This thesis reports works of two aspects on death domain fold proteins:First, protein-protein interaction is the base of life and the reason of some diseases, so study on it can make for preventability, diagnoses of some diseases and count with drug design or target drug. Protein complex is special example of protein-protein interaction. Commonly it is realized that key residues are key factors for protein function and stabilization. Key residues are so called hot spot. In this thesis we define the inter-residue contact with all-atom interaction energy to identify the key residues in the death domain fold proteins. Moreover, the key residues we got are the same as the results of experiment and our results are also consistent with the approved conclusions others got. This gives feasibility to predict hot spot or key residues of complex and help to the study on protein interaction.Second, after Anfinsen's experiment it is widely accepted that the tertiary structure of protein is determined by its amino acid sequence. Based on the conclusion, our work is to study the sequences of death domain fold proteins to find the hidden information which decide the tertiary structure. In order to eliminate the influence of random noise, we use p-value as 0.05, which are considered significant. The results show it really has some similar subsequences in the protein sequence and the sequence is symmetric if the tertiary structure is symmetric. We get different result when using different physical character to classify the amino acids and then relate it with the chemical bonds and physical effect which can stabilize protein. We find the hydrophobicity and hydrophilicity may be more important to structural symmetry.