Skip to main content
Log in

Molecular shape and dipole moment of alamethicin-like synthetic peptides

  • Published:
European Biophysics Journal Aims and scope Submit manuscript

Abstract

The peptides Boc-(l-Ala-Aib-l-Ala-Aib-l-Ala)n-OMe, with n=2 (P10) and n=4 (P20), have been synthesized as purely hydrophobic models of the antibiotic alamethicin, which is known to be a voltage-dependent pore former in membranes and is apparently α-helical in lipophilic media. These peptides were investigated in 1-octanol, a solvent which resembles the membrane environment. From dielectric dispersion studies quantitative information on the molecular shape and dipole moments could be derived. Further independent data concerning conformation and extent of aggregation of the peptides were obtained by circular dichroism and ultracentrifuge measurements. The results suggest that the peptides assume the form of elongated particles having a significant amount of ordered secondary structure and carrying a dipole parallel to the long axis. Apparently the monomeric peptide molecules undergo, to some extent, a head-to-tail aggregation which is slightly enhanced at lower temperatures. Based on the high-frequency parts of the dielectric dispersion curves the lengths, diameters, and dipole moments of the monomer particles have been determined as 22.5 Å, 10 Å, 36 D (P10) and 28.5 Å, 12 Å, 64 D (P20).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bevington PR (1969) Data reduction and error analysis for the physical sciences, chap 11. McGraw-Hill, New York

    Google Scholar 

  • Boheim G, Kolb HA (1978) Analysis of the multi-pore system of alamethicin in a lipid membrane. J Membr Biol 38:99–150

    Google Scholar 

  • Boheim G, Hanke W, Jung G (1983) Alamethicin pore formation: Voltage-dependent flip-flop of α-helix dipoles. Biophys Struct Mech 9:181–191

    Google Scholar 

  • Brückner H, Jung G (1982) Synthesis of l-Prolyl-leucyl-α-aminoisobutyryl-α-aminoisobutyryl-glutamyl-valinol and proof of identity with the isolated C-terminal fragment of trichotoxin A40. Liebigs Ann Chem 1982:1677–1699; and refs. cited therein

    Google Scholar 

  • Chen YH, Yang JT, Chau KH (1974) Determination of the helix and β-form of proteins in aqueous solution by circular dichroism. Biochemistry 13:3350–3359

    Google Scholar 

  • Fox RO, Richards FM (1982) A voltage gated ion channel model inferred from the crystal structure of alamethicin at 1.5 Å resolution. Nature (London) 300:325–330

    Google Scholar 

  • Hall JE, Vodyanov I, Balasubramanian TM, Marshall GR (1984) Alamethicin. A rich model for channel behavior. Biophys J 45:233–247

    Google Scholar 

  • Hanke W, Methfessel C, Wilmsen H-U, Katz E, Jung G, Boheim G (1983) Melittin and chemically modified trochotoxin form alamethicin-like multistate pores. Biochim Biophys Acta 727:108–114

    Google Scholar 

  • Jung G, Dubischar W, Leibfritz D (1975) Conformational changes of alamethicin induced by solvent and temperature. Eur J Biochem 54:395–409

    Google Scholar 

  • Jung G, Bosch R, Katz E, Schmitt H, Voges KP, Winter W (1983 a) Stabilizing effects of 2-methylalanine residues on β-turns and α-helices. Biopolymers 22:241–246

    Google Scholar 

  • Jung G, Katz E, Schmitt H, Voges KP, Menestrina G, Boheim G (1983 b) Conformational requirements for the potential dependent pore formation of the peptide antibiotics alamethicin, suzukacillin and trichotoxin. In: Spach G (ed) Physical chemistry of transmembrane ion motions. Stud Phys Theor Chem, vol 24. Elsevier, Amsterdam, pp 349–357

    Google Scholar 

  • Jung G, Boheim G, Bosch R, Brückner H, Hartter P, Katz E, König WA, Schmitt H, Voges KP, Winter W (1984) Primary and secondary structures of peptides which form voltage-dependent pores in lipid bilayers. In: Voelter W et al. (eds) Chemistry of peptides and proteins, vol 2. W de Gruyter, Berlin, pp 215–226

    Google Scholar 

  • Mathew MK, Balaram P (1983) A helix dipole model for alamethicin and related transmembrane channels. FEBS Lett 157:1–5

    Google Scholar 

  • Meyer P, Reusser F (1967) A polypeptide antibacterial agent isolated from Trichoderma Viride. Experientia (Basel) 23:85–86

    Google Scholar 

  • Mumford SA, Phillips JWC (1950) The physical properties of some aliphatic compounds. J Chem Soc (London) 75–81

  • Riddick JA, Bunger WB (1970) Organic solvents. In: Weissberger A (ed) Techniques of chemistry, vol 2. Wiley Interscience, New York, p 181

    Google Scholar 

  • Sano T, Schwarz G (1983) Structure and dipole moment of melittin molecules in butanol/water as derived from dielectric dispersion and circular dichroism. Biochim Biophys Acta 745:189–193

    Google Scholar 

  • Schwarz G (1977) Chemical transitions of biopolymers induced by an electric field and their effects in dielectrics and birefringence. Ann NY Acad Sci 303:190–197

    Google Scholar 

  • Schwarz G, Savko P (1982) Structural and dipolar properties of the voltage-dependent pore former alamethicin in octanol/dioxane. Biophys J 39:211–219

    Google Scholar 

  • Schwarz G, Savko P, Jung G (1983) Solvent dependent structural features of the membrane active peptide trichotoxin 40 as reflected in its dielectric dispersion. Biochim Biophys Acta 718:419–428

    Google Scholar 

  • Wada A (1976) The α-helix as an electric macro-dipole. Adv Biophys 9:1–63

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rizzo, V., Schwarz, G., Voges, K.P. et al. Molecular shape and dipole moment of alamethicin-like synthetic peptides. Eur Biophys J 12, 67–73 (1985). https://doi.org/10.1007/BF00260429

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00260429

Key words

Navigation