Conformation and orientation of penetratin in phospholipid membranes

Conformation and orientation of penetratin in phospholipid membranes
Engineering Village 2
2006 Elsevier Inc.
Accession number: 8850266

Title: Conformation and orientation of penetratin in phospholipid membranes

Authors: Clayton, A.H.A.1 ; Atcliffe, B.W.1 ; Howlett, G.J.1 ; Sawyer, W.H.1

Author affiliation: 1 Russell Grimwade Sch. of Biochem. & Molecular Biol., Melbourne Univ., Vic., Australia

Serial title: Journal of Peptide Science

Abbreviated serial title: J. Pept. Sci. (USA)

Volume: 12

Issue: 3

Publication date: March 2006

Pages: 233-8

Language: English

ISSN: 1075-2617


Document type: Journal article (JA)

Publisher: John Wiley & Sons Ltd in Assoc. with the European Peptide Soc

Country of publication: USA

Material Identity Number: H334-2006-003

Abstract: The binding, conformation and orientation of a hydrophilic vector peptide penetratin in lipid membranes and its state of self-association in solution were examined using circular dichroism (CD), analytical ultracentrifugation and fluorescence spectroscopy. In aqueous solution, penetratin exhibited a low helicity and sedimented as a monomer in the concentration range ~50-500 HM. The partitioning of penetratin into phospholipid vesicles was determined using tryptophan fluorescence anisotropy titrations. The apparent penetratin affinity for 20% phosphatidylserine/80% egg phosphatidylcholine vesicles was inversely related to the total peptide concentration implying repulsive peptide-peptide interactions on the lipid surface. The circular dichroism spectra of the peptide when bound to unaligned 20% phosphatidylserine/80% egg phosphatidylcholine vesicles and aligned hydrated phospholipid multilayers were attributed to the presence of both a-helical and ?-turn structures. The orientation of the secondary structural elements was determined using oriented circular dichroism spectroscopy. From the known circular dichroism tensor components of the a-helix, it can be concluded that the orientation of the helical structures is predominantly perpendicular to the membrane surface, while that of the ?-type carbonyls is parallel to the membrane surface. On the basis of our observations, we propose a novel model for penetratin translocation

Number of references: 26

Inspec controlled terms: biochemistry - biological techniques - biomembranes - circular dichroism - fluorescence spectroscopy - lipid bilayers - molecular biophysics

Uncontrolled terms: penetratin orientation - penetratin conformation - phospholipid membranes - hydrophilic vector peptide penetratin - lipid membranes - self-association state - analytical ultracentrifugation spectroscopy - fluorescence spectroscopy - aqueous solution - monomer - phospholipid vesicles - tryptophan fluorescence anisotropy titration - apparent penetratin affinity - phosphatidylserine - egg phosphatidylcholine vesicles - peptide concentration - repulsive peptide-peptide interaction - lipid surface - circular dichroism spectra - hydrated phospholipid multilayers - secondary structural element orientation - oriented circular dichroism spectroscopy - circular dichroism tensor components - penetratin translocation model

Inspec classification codes: A8780 Biophysical instrumentation and techniques - A8720E Natural and artificial biomembranes - A8725F Physics of subcellular structures - A8715K Biomolecular interactions, charge transfer complexes - A8715B Biomolecular structure, configuration, conformation, and active sites - A3345D Optical activity, optical rotation, circular dichroism in molecules - A8715D Physical chemistry of biomolecular solutions; condensed states

Treatment: Experimental (EXP)

Discipline: Physics (A)

DOI: 10.1002/psc.715

Database: Inspec

Copyright 2006, The Institution of Engineering and Technology
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