Proteomics Expression Profiles And Data Base Construction For The Fluoride-resistant Strain And Parental Strain Of The Streptococcus Mutans

Proteomics Expression Profiles and Data Base Construction for the Fluoride-resistant Strain and Parental Strain of the Streptococcus MutansCaries is a kind of bacteria-infected disease of the tooth hard tissue, which is also the most common disease occurred in oral cavity. However, its occurrence has very special character, which is different from other kinds of bacteria-infected diseases. So it is a very important subject to investigate its occurrence, development and new method of prevention in this field. The development of the theory and lab technology in biochemistry and proteomics, esp. the genome sequence of the Streptococcus Mutans(S.M.) strain, UA159, has greatly promoted the research of caries eteology and prevention, which had a profound effect on the screening of anti-caries medicine and the design of treatment vaccine.The S.M. is the main pathogenic bacteria. It has the character of acidogenicity, acid proof and high adherence to hard tissue. It also can produce polysaccharide both in vivo and in vitro of cells. The prevention of caries is mainly obtainned by interferring the chemical process of caries, and the appliance of fluoride was one of the most important outcomes in the field of preventive dentistry in 20th century. In recent years, the prevalence of caries in some developed countries had been greatly controlled, which was closely related with the appliance of fluoride. The fluoride could be used topically, as well as systematically. Now, researchers had come to the conclusion that the anti-caries effect of fluoride mainly occurred topically, instead of systematically. Long-term use of fluoride preparation could induce the fluoride-resistant strain of M.S.. From those patients who had used high concentration of fluoride sodium gel for rampant caries prevention, researchers had successfully insolated the fluoride-resistant Strain of M.S.. Then, some other investigaters had also insolated the fluoride-resistant strain of M.S. from Xerostomia patients. These researches suggested that the fluoride-resistant strain of M.S. could live in some special people. The fluoride-resistant strain of M.S. could reduce the anti-caries effect of fluoride and are more difficult to be suppressed, which had given us a new question in this area focussed by many scholars.Our prophase research about the acid-proof-related genes of ffh, fhs, dgk and dltc from the fluoride-resistant strain of the S.M. showed that these genes have some mutations to different extent compared with that from the parental strain, but we are still short of the data about their encoded proteins. The functions of most newly founded gene-encoded proteins by genome sequencing are still unknown. The functions of those well-known proteins were mostly inferred by analogizing the gene homologues. However, the information about the proteins got from their genes are half-baked. We could not get the informations about decoration, transportation, construction, interactions between proteins themselves, and between proteins and nucleic acids from the level of genome. Genes are the carriers of hereditary information, and their encoded products, the proteins, are the executors of biological activities. The sequence of genome gives us only the hereditary information data, however, the encoded proteins could give us the law of biological activities. This is how the proteomics comes into being, which mainly investigates the compositions and activities of the whole encoded proteins within the cells.The main techonologies in proteomics incluseds two-dimensional electrophoresis (2-DE), new type mass spectra, gel image processing, the sequencing of N-terminal and C-terminal of proteins and polypeptides and their amino acid analysis, two-hybridization system, data base and research system etc. They are mostly used to isolate and identify proteins, and to investigate their interactions.Shotgun is a kind of non-gel isolation and identification technique of proteomics. First, the extracted protein solutions were enzyme digested, then the peptides mixtures were isolated and analysed with capillary liqued phase chromatography fractionation and tandem mass spectrometry respectively. With these results, it sesearches the data base and get the first-stage construction information of the peptides by a special arithmetic method, and get the identification results of the proteins. This method is specially suitable for the low protein content samples, which is also the key point success for our research.The identification of microorganism-related proteins is the fundamental goal of microorganism proteomics research. The related genomes could be expressed under different environments. The microorganism stress phosiology is the main part of microorganism proteomics, and it could thoroghly clarify the mechanism by which the microorganism adapt the multiple environments.There have some achievements about the proteomics of the S.M. from abroad, which concentrate mainly on two points:one is the comparison of the proteomics between biofilm state and floating state of the S.M., the other is the comparison of the S.M. proteomics between neutral and acid cultural conditions. By comparing the difference between peoteomics, we could get the peoteins related with caries in pathogenic bacteria.The results from genome sequence of the S.M. showed that it is highly homologinized with the Streptococcus Pneumoniae, and about half of the proteins from the S.M. have similar functions with those from the Streptococcus Pneumoniae. Now, it has been certified that one gene could encode more than one coresponding proteins, and one gene could not decide directly one functional protein. Thus, our research started from all the protein information we have got. We insolated and identified the whole proteomics of the fluoride-resistant strain and parental strain of the S.M. with the shotgun technique. We finally got 814 kinds of proteins from the fluoride-resistant strain of the S.M. with new type mass spectra and data base research system, of which we got 246 kinds of proteins with high reliability, and 58 kinds of independently expressed proteins. Among the 246 kinds of proteins, the molecular function of 32.9% of them are already known, with the rest 67.1% unkown; and the biological process of 29.2% of them are already known, with the rest 70.8% unkown. The cellular location of all of them remains unknown until now. From all the results, we have successfully constructed the proteomics data base of the fluoride-resistant strain and parental strain of the S.M..The innovation of our research was that it is the first time to analyse the proteomics of the fluoride-resistant strain and parental strain(UA159) of the S.M. with the technique of Shotgun. On basis of the protein identification and related information searched from the NCBI protein data base of the S.M., we have preliminarily constructed the protein expression atlas and proteomics data base of the fluoride-resistant strain and parental strain of the S.M.. The results could provide the theoretical, technical, and experimental basis for analysing the functions of proteins encoded by caries-related genes from the fluoride-resistant strain and parental strain of the S.M..