Change search
ReferencesLink to record
Permanent link

Direct link
The membrane-induced structure of melittin is correlated with the fluidity of the lipids
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Show others and affiliations
2007 In: Biochimica et biophysica acta, ISSN 0006-3002, Vol. 1768, no 1, 115-121 p.Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2007. Vol. 1768, no 1, 115-121 p.
URN: urn:nbn:se:su:diva-24833ISI: 000243733600014OAI: diva2:198395
Part of urn:nbn:se:su:diva-7488Available from: 2008-05-08 Created: 2008-05-08Bibliographically approved
In thesis
1. Structure and Dynamics of Membrane Associated Peptides
Open this publication in new window or tab >>Structure and Dynamics of Membrane Associated Peptides
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The peptide-membrane interaction is a key element for many biological functions, from cell signaling to cell internalization. In this thesis the peptide-membrane interaction of six different peptides have been studied with respect to their structure, membrane location and dynamics with spectroscopic methods. Penetratin and the N-terminal sequence of the bovine prion protein (1-30), bPrPp, belong to a class of peptides called cell-penetrating peptides (CPPs). CPPs are short, often highly basic peptides that have the ability to facilitate translocation of an attached hydrophilic cargo over cell-membrane. CD and NMR spectroscopy reveled that penetratin, the (supposedly) non-penetrating mutant pentratin(W48F,W56F) and bPrPp are all highly helical in membrane mimicking media. The position with respect to the bilayer is, however, very different for the three peptides, Penetratin is residing on the membrane surface with a slight tilt while bPrPp is transmembrane and penetratin(W48F,W56F) is somewere in between. These differences can explain the different impact these peptides have on membranes

We have also shown that penetratin can escape from vesicles when an electrochemical or pH gradient is present over the membrane, which support endocytotic internalization.

Melittin is a 26 amino acid long residue long peptide and is the major component of the European honey bee venom. Many studies have shown that melittin induces a transient pore that causes leakage in both natural and artificial membranes. In paper IV we used melittin as a model-peptide to investigate how peptides affect lipid dynamics in model-membranes. We showed that carbon-13 relaxation of the lipids could be used to characterize peptide induced changes in lipid dynamics

The voltage sensor is a domain of the voltage-dependent potassium channel containing several positively charged amino acids (usually arginines). The sensor undergoes a conformational change as a response to a membrane potential. Here, we have studied the membrane location of two fragments corresponding to the “paddle” domain of two different potassium channels, KvAP and HsapBK. NMR and fluorescence studies indicate that both peptides reside inside of the hydrophobic interior of the bilayer, which show that the fragment behave the same way as it does in the intact protein.

All six of these peptides interact strongly with model-membranes and adopt a helical conformation even though they have very different biological function. The difference in biological function can instead be explained by the variation in membrane position and membrane dynamics of these peptides

Place, publisher, year, edition, pages
Stockholm: Institutionen för biokemi och biofysik, 2008. 51 p.
National Category
Research subject
urn:nbn:se:su:diva-7488 (URN)978-91-7155-641-7 (ISBN)
Public defence
2008-05-30, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 12 A, Stockholm, 10:00
Available from: 2008-05-08 Created: 2008-05-08Bibliographically approved

Open Access in DiVA

No full text

By organisation
Department of Biochemistry and Biophysics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 48 hits
ReferencesLink to record
Permanent link

Direct link