抗菌肽（AMPs）被視為植物防御系統(tǒng)的一部分,是一種可抑制多種植物病原菌的活性物質。從細菌到植物,抗菌肽可以存在于所有形式的生命中。SM-985是從大芻草（Zea mays ssp.mexicana）c DNA文庫中分離的陽離子抗菌肽。使用具有不同算法的計算預測服務器來篩選大芻草c DNA文庫中的抗菌肽,并且預測結果表明,SM-985具有高概率為抗菌肽。SM-985是一種富含精氨酸的肽,由21個氨基酸組成（分子量:2671.06 Da）,作為抗菌肽其物理化學性質非常理想,凈電荷（+8）,疏水率23%,Boman指數(shù)5.19 kcal/mol,等電點12.95。SM-985肽具有兩親性α-螺旋構象。SM-985對6種植物病原細菌具有抗菌活性,對革蘭氏陽性指示菌Clavibacter fangii,C.michiganesis ssp.michiganesis和B.subtilis 168的MIC為8μM,MBC為16μM;SM-985對革蘭氏陰性指示菌Pseudomonas syringae pv.tomato DC3000,Ralstonia solanacearum,Xanthomo... 

【文章頁數(shù)】：102 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
List of abbreviations
1 INTRODUCTION
    1.1 Literature review
        1.1.1 Teosinte as its relationship with maize
        1.1.2 Complementary DNA(c DNA)library
        1.1.3 Antimicrobial peptides(AMPs)
        1.1.4 Prediction of AMPs
        1.1.5 Different techniques of AMPs isolation
        1.1.6 Antimicrobial activity
        1.1.7 AMPs and plant protection
    1.2 Objectives of the study
2 MATERIALS AND METHODS
    2.1 Construction of induced c DNA library
        2.1.1 The preparation of teosinte c DNA
        2.1.2 Cloning of teosinte c DNAs
    2.2 Screening of c DNA library and bioinformatic analysis
        2.2.1 c DNAs sequencing and analysis
        2.2.2 In silico prediction-based screening for AMPs and bioinformatic analysis
    2.3 In vitro antimicrobial activity
        2.3.1 SM-985 peptide
        2.3.2 Minimal Inhibition Concentration(MIC)and Minimal Bactericidal Concentration(MBC)assays
        2.3.3 Minimal Lethal Concentration(MLC)assay
        2.3.4 Cell membrane integrity assay
    2.4 FITC-Labeled-SM-985 peptide
    2.5 In vivo antimicrobial activity assay
    2.6 Scanning Electron Microscopy(SEM) &Transmission Electron Microscopy assays(TEM)
        2.6.1 Scanning Electron Microscopy
        2.6.2 Transmission Electron Microscopy
    2.7 Influence of calcium chloride on SM-985 antimicrobial activity
3 RESULTS
    3.1 Construction of c DNA library
    3.2 In silico AMP prediction and characteristics of SM-989 peptide
    3.3 In vitro antimicrobial activity
        3.3.1 Determination of MICs and MBCs of SM-985 peptide
        3.3.2 The MLC of SM-985 peptide causes complete death for all bacterial indicators
        3.3.3 SM-985 increases the cell membrane permeability
    3.4 SM-985 localization
        3.4.1 FITC-Labeled SM-985 peptide interacts with bacterial cell membrane
        3.4.2 FITC-SM-985 maintains the antimicrobial activity
    3.5 In vivo antimicrobial activity
    3.6 SM-985 causes distinct damage to the bacterial cell membrane
    3.7 Calcium chloride inhibits the SM-985 antimicrobial activity
4 DISCUSSION
5 CONCLUSIONS,SIGNIFICANCE,AND RESEARCH PROSPECTS
    5.1 Conclusions
    5.2 Significance
    5.3 Research prospects
References
Appendices
Acknowledgments



本文編號：3655727