Aurein is a cationic antimicrobial peptide, rich in phenylalanine residues. Although the peptide has been extensively studied, its mechanism of action is not fully understood and has not been established. This project...Aurein is a cationic antimicrobial peptide, rich in phenylalanine residues. Although the peptide has been extensively studied, its mechanism of action is not fully understood and has not been established. This project is focused on studying the interactions of aurein with model biological membranes and antimalarials using Fourier Transform Infrared (FTIR), fluorescence, dynamic light scattering (DLS), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. FTIR data revealed conformational changes to the secondary structure of the peptide in the presence of the model membranes. The strongest interactions of aurein were found with DOPC and lipid raft systems. Fluorescence data revealed some differences in the mechanism of interaction between aurein and lipid rafts. Topographical analysis was performed using atomic force microscopy (AFM). AFM images of the peptide with its lipid rafts showed a change in surface roughness suggesting a different mechanism of interaction. DLS data in agreement with FTIR confirmed that aurein interacts differently with the lipid rafts. The results gathered from this study provided new insights on the interaction of aurein. On the other hand, drug-drug interaction issues continue to present a major dilemma for the clinician caring for complex patients such as those infected with infectious disease. This study has examined the interaction of aurein with quinine, primaquine, and chloroquine. Significant interactions between aurein and antimalarials occured at a higher concentration of antimalarials. Interactions between aurein and anti-malarials reveal a strong interaction between aurein and primaquine. Interactions between aurein and quinine or chloroquine were found to be weak and negligible. FTIR, TGA, and DSC may be used in a complementary way to gain insights into the possible drug-drug interactions involving aurein. These studies are needed to initiate in vivo controlled interaction studies between antibiotics and antimalarials.展开更多
文摘目的探讨不同时间高浓度氧对肺泡Ⅱ型细胞(AECII)内质网自噬与肺泡表面活性物质产生功能之间的关系。方法将大鼠RLE-6TN细胞分为对照组(C组,21%O2常规培养72 h)、高氧H1、H2、H3、H4组(95%O2分别培养12、24、48、72 h)。实时荧光定量PCR法检测内质网自噬受体ATL3、CCPG1、FAM134B、RTN3、SEC62的mRNA水平,Western blot法检测内质网自噬相关蛋白ATL3、CCPG1、FAM134B、RTN3、SEC62的水平,ELISA法检测各组二棕榈酰卵磷脂(DPPC)水平。结果与C组相比,H1组ATL3、SEC62的mRNA水平、CCPG1的蛋白水平、DPPC产量下降(P<0.05),CCPG1、FAM134B、RTN3的mRNA水平、ATL3、FAM134B、RTN3、SEC62的蛋白水平显著下降(P均<0.01);H2组ATL3、CCPG1、FAM134B、RTN3、SEC62的mRNA水平、ATL3、CCPG1、FAM134B、RTN3、SEC62的蛋白水平差异无统计学意义(P均>0.05),DPPC产量增高(P<0.05);H3、H4组ATL3、CCPG1、FAM134B、RTN3、SEC62的mRNA水平、ATL3、CCPG1、FAM134B、RTN3、SEC62的蛋白水平、DPPC产量显著下降(P均<0.01)。与H1组相比,H2组CCPG1、FAM134B的mRNA水平、ATL3、RTN3的蛋白水平、DPPC产量显著增高(P<0.01),SEC62的蛋白水平增高(P<0.05);H3组ATL3、SEC62的蛋白水平显著下降(P<0.01),RTN3的mRNA水平、RTN3的蛋白水平下降(P<0.05);H4组ATL3的mRNA水平、CCPG1的蛋白水平下降(P<0.05)、RTN3的mRNA水平、ATL3、RTN3、SEC62的蛋白水平显著下降(P<0.01)。与H2组相比,H3组、H4组ATL3、CCPG1、FAM134B、RTN3的mRNA水平、ATL3、RTN3、SEC62的蛋白水平、DPPC产量显著下降(P均<0.01);H4组SEC62的mRNA水平下降(P<0.05);H3组CCPG1、FAM134B的蛋白水平下降(P<0.05);H4组CCPG1、FAM134B的蛋白水平显著下降(P<0.01);与H3组相比,H4组ATL3、RTN3、SEC62的蛋白水平显著下降(P<0.01);其余各组差异均无统计学意义(P均>0.05)。结论高氧12 h AECII内质网自噬水平、DPPC产量下降;高氧24 h AECII内质网自噬水平恢复到基础值,DPPC产量达到峰值,48 h后内质网自噬水平、DPPC产量再次下降,72 h后AECII内质网自噬水平、DPPC产量衰减仍保持较低水平,AECII内质网自噬与其功能密切相关。
文摘Aurein is a cationic antimicrobial peptide, rich in phenylalanine residues. Although the peptide has been extensively studied, its mechanism of action is not fully understood and has not been established. This project is focused on studying the interactions of aurein with model biological membranes and antimalarials using Fourier Transform Infrared (FTIR), fluorescence, dynamic light scattering (DLS), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. FTIR data revealed conformational changes to the secondary structure of the peptide in the presence of the model membranes. The strongest interactions of aurein were found with DOPC and lipid raft systems. Fluorescence data revealed some differences in the mechanism of interaction between aurein and lipid rafts. Topographical analysis was performed using atomic force microscopy (AFM). AFM images of the peptide with its lipid rafts showed a change in surface roughness suggesting a different mechanism of interaction. DLS data in agreement with FTIR confirmed that aurein interacts differently with the lipid rafts. The results gathered from this study provided new insights on the interaction of aurein. On the other hand, drug-drug interaction issues continue to present a major dilemma for the clinician caring for complex patients such as those infected with infectious disease. This study has examined the interaction of aurein with quinine, primaquine, and chloroquine. Significant interactions between aurein and antimalarials occured at a higher concentration of antimalarials. Interactions between aurein and anti-malarials reveal a strong interaction between aurein and primaquine. Interactions between aurein and quinine or chloroquine were found to be weak and negligible. FTIR, TGA, and DSC may be used in a complementary way to gain insights into the possible drug-drug interactions involving aurein. These studies are needed to initiate in vivo controlled interaction studies between antibiotics and antimalarials.
