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Infect Immun. Nov 1997; 65(11): 4795–4800.
PMCID: PMC175688

The cytoplasmic membrane is a primary target for the staphylocidal action of thrombin-induced platelet microbicidal protein.


Thrombin-induced platelet microbicidal protein (tPMP-1) is a small, cationic peptide released from rabbit platelets exposed to thrombin in vitro. tPMP-1 is microbicidal against a broad spectrum of bloodstream pathogens, including Staphylococcus aureus. Preliminary evidence suggests that tPMP-1 targets and disrupts the staphylococcal cytoplasmic membrane. However, it is not clear if the cytoplasmic membrane is a direct or indirect target of tPMP-1. Therefore, we assessed the in vitro activity of tPMP-1 versus protoplasts prepared from logarithmic-phase (LOG) or stationary-phase (STAT) cells of the genetically related S. aureus strains 19S and 19R (tPMP-1 susceptible and resistant, respectively). Protoplasts exposed to tPMP-1 (2 microg/ml) for 2 h at 37 degrees C were monitored for lysis (decrease in optical density at 420 nm) and ultrastructural alterations (by transmission electron microscopy [TEM]). Exposure to tPMP-1 resulted in substantial lysis of LOG but not STAT protoplasts of 19S, coinciding with protoplast membrane disruption observed by TEM. Thus, it appears that tPMP-1-induced membrane damage is influenced by the bacterial growth phase but is independent of the staphylococcal cell wall. In contrast to 19S, neither LOG nor STAT protoplasts of 19R were lysed by tPMP-1. tPMP-1-induced membrane damage was further characterized with anionic planar lipid bilayers subjected to various trans-negative voltages. tPMP-1 increased conductance across bilayers at -90 mV but not at -30 mV. Once initiated, a reduction in voltage from -90 to -30 mV diminished conductance magnitude but did not eliminate tPMP-1-mediated membrane permeabilization. Therefore, tPMP-1 appears to directly target the staphylococcal cytoplasmic membrane as a primary event in its mechanism of action. Specifically, tPMP-1 likely leads to staphylococcal death, at least in part by permeabilizing the bacterial membrane in a voltage-dependent manner.

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Selected References

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  • Bechinger B, Zasloff M, Opella SJ. Structure and interactions of magainin antibiotic peptides in lipid bilayers: a solid-state nuclear magnetic resonance investigation. Biophys J. 1992 Apr;62(1):12–14. [PMC free article] [PubMed]
  • Bechinger B, Zasloff M, Opella SJ. Structure and orientation of the antibiotic peptide magainin in membranes by solid-state nuclear magnetic resonance spectroscopy. Protein Sci. 1993 Dec;2(12):2077–2084. [PMC free article] [PubMed]
  • Christensen B, Fink J, Merrifield RB, Mauzerall D. Channel-forming properties of cecropins and related model compounds incorporated into planar lipid membranes. Proc Natl Acad Sci U S A. 1988 Jul;85(14):5072–5076. [PMC free article] [PubMed]
  • Christensen DP, Hutkins RW. Collapse of the proton motive force in Listeria monocytogenes caused by a bacteriocin produced by Pediococcus acidilactici. Appl Environ Microbiol. 1992 Oct;58(10):3312–3315. [PMC free article] [PubMed]
  • Drake TA, Pang M. Staphylococcus aureus induces tissue factor expression in cultured human cardiac valve endothelium. J Infect Dis. 1988 Apr;157(4):749–756. [PubMed]
  • Drake TA, Pang M. Effects of interleukin-1, lipopolysaccharide, and streptococci on procoagulant activity of cultured human cardiac valve endothelial and stromal cells. Infect Immun. 1989 Feb;57(2):507–512. [PMC free article] [PubMed]
  • Fujii G, Selsted ME, Eisenberg D. Defensins promote fusion and lysis of negatively charged membranes. Protein Sci. 1993 Aug;2(8):1301–1312. [PMC free article] [PubMed]
  • Hancock RE. Aminoglycoside uptake and mode of action-with special reference to streptomycin and gentamicin. II. Effects of aminoglycosides on cells. J Antimicrob Chemother. 1981 Dec;8(6):429–445. [PubMed]
  • Hladky SB, Haydon DA. Ion transfer across lipid membranes in the presence of gramicidin A. I. Studies of the unit conductance channel. Biochim Biophys Acta. 1972 Aug 9;274(2):294–312. [PubMed]
  • Hoffmann A, Dimroth P. The electrochemical proton potential of Bacillus alcalophilus. Eur J Biochem. 1991 Oct 15;201(2):467–473. [PubMed]
  • Kagan BL, Selsted ME, Ganz T, Lehrer RI. Antimicrobial defensin peptides form voltage-dependent ion-permeable channels in planar lipid bilayer membranes. Proc Natl Acad Sci U S A. 1990 Jan;87(1):210–214. [PMC free article] [PubMed]
  • Koo SP, Bayer AS, Sahl HG, Proctor RA, Yeaman MR. Staphylocidal action of thrombin-induced platelet microbicidal protein is not solely dependent on transmembrane potential. Infect Immun. 1996 Mar;64(3):1070–1074. [PMC free article] [PubMed]
  • Koo SP, Yeaman MR, Bayer AS. Staphylocidal action of thrombin-induced platelet microbicidal protein is influenced by microenvironment and target cell growth phase. Infect Immun. 1996 Sep;64(9):3758–3764. [PMC free article] [PubMed]
  • Kordel M, Benz R, Sahl HG. Mode of action of the staphylococcinlike peptide Pep 5: voltage-dependent depolarization of bacterial and artificial membranes. J Bacteriol. 1988 Jan;170(1):84–88. [PMC free article] [PubMed]
  • Lehrer RI, Ganz T, Szklarek D, Selsted ME. Modulation of the in vitro candidacidal activity of human neutrophil defensins by target cell metabolism and divalent cations. J Clin Invest. 1988 Jun;81(6):1829–1835. [PMC free article] [PubMed]
  • Lehrer RI, Barton A, Daher KA, Harwig SS, Ganz T, Selsted ME. Interaction of human defensins with Escherichia coli. Mechanism of bactericidal activity. J Clin Invest. 1989 Aug;84(2):553–561. [PMC free article] [PubMed]
  • Ojcius DM, Young JD. Cytolytic pore-forming proteins and peptides: is there a common structural motif? Trends Biochem Sci. 1991 Jun;16(6):225–229. [PubMed]
  • Pestka S. Inhibitors of ribosome functions. Annu Rev Microbiol. 1971;25:487–562. [PubMed]
  • Sahl HG, Kordel M, Benz R. Voltage-dependent depolarization of bacterial membranes and artificial lipid bilayers by the peptide antibiotic nisin. Arch Microbiol. 1987;149(2):120–124. [PubMed]
  • Schuhardt VT, Klesius PH. Osmotic fragility and viability of lysostaphin-induced staphylococcal spheroplasts. J Bacteriol. 1968 Sep;96(3):734–737. [PMC free article] [PubMed]
  • Schüller F, Benz R, Sahl HG. The peptide antibiotic subtilin acts by formation of voltage-dependent multi-state pores in bacterial and artificial membranes. Eur J Biochem. 1989 Jun 1;182(1):181–186. [PubMed]
  • Selsted ME, Szklarek D, Lehrer RI. Purification and antibacterial activity of antimicrobial peptides of rabbit granulocytes. Infect Immun. 1984 Jul;45(1):150–154. [PMC free article] [PubMed]
  • Shimoda M, Ohki K, Shimamoto Y, Kohashi O. Morphology of defensin-treated Staphylococcus aureus. Infect Immun. 1995 Aug;63(8):2886–2891. [PMC free article] [PubMed]
  • Sud IJ, Feingold DS. Phospholipids and fatty acids of Neisseria gonorrhoeae. J Bacteriol. 1975 Nov;124(2):713–717. [PMC free article] [PubMed]
  • Sullam PM, Frank U, Yeaman MR, Täuber MG, Bayer AS, Chambers HF. Effect of thrombocytopenia on the early course of streptococcal endocarditis. J Infect Dis. 1993 Oct;168(4):910–914. [PubMed]
  • Van Schaik FW, Veerkamp JH. Biochemical changes in Bifidobacterium bifidum var. pennsylvanicus after cell wall inhibition. VIII. Composition and metabolism of phospholipids at different stages and conditions of growth. Biochim Biophys Acta. 1975 May 22;388(2):213–225. [PubMed]
  • Wu T, Yeaman MR, Bayer AS. In vitro resistance to platelet microbicidal protein correlates with endocarditis source among bacteremic staphylococcal and streptococcal isolates. Antimicrob Agents Chemother. 1994 Apr;38(4):729–732. [PMC free article] [PubMed]
  • Yeaman MR, Puentes SM, Norman DC, Bayer AS. Partial characterization and staphylocidal activity of thrombin-induced platelet microbicidal protein. Infect Immun. 1992 Mar;60(3):1202–1209. [PMC free article] [PubMed]
  • Yeaman MR, Ibrahim AS, Edwards JE, Jr, Bayer AS, Ghannoum MA. Thrombin-induced rabbit platelet microbicidal protein is fungicidal in vitro. Antimicrob Agents Chemother. 1993 Mar;37(3):546–553. [PMC free article] [PubMed]
  • Yeaman MR, Sullam PM, Dazin PF, Bayer AS. Platelet microbicidal protein alone and in combination with antibiotics reduces Staphylococcus aureus adherence to platelets in vitro. Infect Immun. 1994 Aug;62(8):3416–3423. [PMC free article] [PubMed]
  • Yeaman MR, Soldan SS, Ghannoum MA, Edwards JE, Jr, Filler SG, Bayer AS. Resistance to platelet microbicidal protein results in increased severity of experimental Candida albicans endocarditis. Infect Immun. 1996 Apr;64(4):1379–1384. [PMC free article] [PubMed]
  • Yeaman MR, Tang YQ, Shen AJ, Bayer AS, Selsted ME. Purification and in vitro activities of rabbit platelet microbicidal proteins. Infect Immun. 1997 Mar;65(3):1023–1031. [PMC free article] [PubMed]

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