Specific and selective peptide-membrane interactions revealed using quartz crystal microbalance.
The skin secretions of Australian tree frogs are rich in peptides with potential antimicrobial activity. They interrupt bacterial cell membranes, although precisely how and whether all peptides have the same mechanism is not known. The interactions of three of these peptides-aurein 1.2, maculatin 1.1, and caerin 1.1 with supported phospholipid bilayers-are examined here using quartz crystal microbalance and atomic force microscopy. These approaches enabled us to reveal variations in material structure and density as a function of distance from the sensor surface when comparing mass sensorgrams over a range of harmonics of the natural resonance of the sensor crystal and hence obtain for the first time to our knowledge a mechanistic assessment of membrane disruption. We found that caerin inserted into the bilayer in a transmembrane manner, regardless of concentration and phospholipid composition consistent with a pore-forming mechanism. In contrast, maculatin and aurein interacted with membranes in a concentration-dependent manner. At low concentrations (<5 microM), maculatin exhibited transmembrane incorporation whereas aurein was limited to surface association. Upon reaching a threshold value of concentration, both peptides lysed the membrane. In the case of maculatin, the lysis progressed in a slow, concentration-dependent manner, forming mixed micelles, as shown by atomic force microscopy imaging. Aurein-induced lysis proceeded to a sudden disruption, which is consistent with the "carpet" mechanism. Both maculatin and aurein exhibit specificity toward phospholipids and thus have potential as candidates as antimicrobial drugs.
Mechler
Adam
A
School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
Praporski
Slavica
S
Atmuri
Kiran
K
Boland
Martin
M
Separovic
Frances
F
Martin
Lisandra L
LL
D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D012680:Sensitivity and Specificity; D014159:Transducers
D023181:Antimicrobial Cationic Peptides; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010455:Peptides
Eur J Biochem. 2000 Apr;267(7):1894-908
10727928
Eur J Biochem. 1997 Jul 15;247(2):545-57
9266696
Biochim Biophys Acta. 1999 Dec 15;1462(1-2):55-70
10590302
Eur J Biochem. 1999 Oct;265(2):627-37
10504394
Biophys J. 1998 Sep;75(3):1397-1402
9726940
Curr Opin Chem Biol. 2000 Dec;4(6):704-9
11102877
Biochim Biophys Acta. 1997 Mar 13;1324(2):309-19
9092717
Biochemistry. 1996 Sep 3;35(35):11361-8
8784191
Peptides. 2001 Oct;22(10):1629-41
11587791
Clin Chem. 1991 Sep;37(9):1497-501
1893574
Biochim Biophys Acta. 2004 Jul 1;1664(1):31-7
15238255
Q Rev Biophys. 1977 Feb;10(1):1-34
327501
Biochemistry. 2002 Feb 26;41(8):2814-24
11851429
Rapid Commun Mass Spectrom. 2001;15(18):1726-34
11555873
Biophys J. 2000 Dec;79(6):3153-63
11106620
Proc Natl Acad Sci U S A. 1984 Oct;81(19):6159-63
6333027
J Electron Microsc (Tokyo). 2002;51(1):1-9
12003236
Langmuir. 2006 Apr 11;22(8):3497-505
16584220
Chem Phys Lipids. 2003 Sep;125(1):69-82
14625077
Biophys J. 1991 Dec;60(6):1401-10
1777565
Phys Rev Lett. 2000 Jun 5;84(23):5443-6
10990964
Eur J Biochem. 2000 Sep;267(17):5330-41
10951191
Biochemistry. 2004 Feb 3;43(4):937-44
14744137
Biophys J. 2005 Sep;89(3):1874-81
15994901
Chem Phys Lipids. 2003 Jan;122(1-2):107-20
12598042
J Pept Sci. 2004 Jul;10(7):414-22
15298176
FEBS Lett. 2002 Feb 13;512(1-3):47-51
11852050
Eur Biophys J. 2004 Apr;33(2):109-16
13680211
Biochim Biophys Acta. 1999 Dec 15;1462(1-2):71-87
10590303
J Biol Chem. 2005 Mar 18;280(11):10646-54
15615707
Science. 1995 Apr 7;268(5207):92-4
7701347
Biophys J. 2001 Sep;81(3):1475-85
11509361
Biophys J. 2003 Nov;85(5):3035-47
14581204
Biochemistry. 1999 Aug 3;38(31):9956-63
10433702
Chem Phys Lipids. 2004 Nov;132(1):3-14
15530443
Biochemistry. 2004 Mar 30;43(12):3590-9
15035629
Anal Chem. 2001 Dec 15;73(24):5796-804
11791547
J Phys Chem B. 2006 Oct 26;110(42):21282-6
17048957
Peptides. 2004 Jun;25(6):1035-54
15203252
J Pept Sci. 1998 Apr;4(2):111-5
9620615
Biopolymers. 2002;66(4):236-48
12491537
Langmuir. 2004 Mar 30;20(7):2809-12
15835157