کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10796737 | 1053184 | 2015 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Studies of the interactions of ursane-type bioactive terpenes with the model of Escherichia coli inner membrane-Langmuir monolayer approach
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Pentacyclic triterpenes (PT), ursolic acid (Urs), and α-amyrin (AMalf) are natural products exhibiting broad spectrum of antibacterial activity. These compounds are membrane-active and can disorder bacterial membranes when incorporated; however, the exact mechanism of their membrane activity is unknown. In our studies, we applied Langmuir monolayer technique supported by Brewster angle microscopy to model the interactions of the selected PT with the lipid matrix of E. coli inner membrane. As the model membrane, we applied mixtures (75/25 mole/.mole %) of the representative Escherichia coli phosphatidylethanolamine (POPE), with the cardiolipin (ECCL) or phosphatidylglycerol (ECPG) extracted from the E. coli inner membrane. On the basis of the recorded isotherms, we performed thermodynamic analysis and calculated free energy of mixing ÎGexc. It turned out that the phospholipids forming the inner membrane of E. coli are ideally miscible, whereas in binary systems composed of PT and POPE, negative deviations from ideality indicating attractive interactions between the investigated PT and POPE molecules were observed. On the other hand, in ternary systems composed of PT, POPE and one of the E. coli anionic phospholipids large positive changes in ÎGexc were observed. Thus, both PT exhibit disorganizing effect on the model E. coli membrane. It was also proved that at low terpene proportion, AMalf can be more active than Urs. However, at higher proportion Urs incorporation can lead to the disintegration of cardiolipin-rich domains present in bacterial membrane.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1848, Issue 2, February 2015, Pages 469-476
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1848, Issue 2, February 2015, Pages 469-476
نویسندگان
Marcin Broniatowski, Patrycja Mastalerz, MichaÅ FlasiÅski,