Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function
Artikel i vetenskaplig tidskrift, 2012

Cell-penetrating peptides and antimicrobial peptides are two classes of positively charged membrane active peptides with several properties in common. The challenge is to combine knowledge about the membrane interaction mechanisms and structural properties of the two classes to design peptides with membrane-specific actions, useful either as transporters of cargo or as antibacterial substances. Membrane active peptides are commonly rich in arginine and tryptophan. We have previously designed a series of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations assay (MIC), circular dichroism (CD) and linear dichroism (LD). The results show that the arg/trp peptides inhibit the growth of the two gram positive strains Staphylococcus aureus and Staphylococcus pyogenes, with some individual variations depending on the position of the tryptophans. No inhibition of the gram negative strains Proteus mirabilis or Pseudomonas aeruginosa was noticed. CD indicated that when bound to lipid vesicles one of the peptides forms an a-helical like structure, whereas the other five exhibited rather random coiled structures. LD indicated that all six peptides were somehow aligned parallel with the membrane surface. Our results do not reveal any obvious connection between membrane interaction and antimicrobial effect for the studied peptides. By contrast cell-penetrating properties can be coupled to both the secondary structure and the degree of order of the peptides.

lipid-membranes

circular-dichroism

orientation

Cell-penetrating peptide

melittin

linear dichroism

rich peptides

bacteria

mechanisms

antimicrobial peptides

Circular

Antimicrobial peptide

Arginine-rich peptide

cell-penetrating peptides

Tryptophan

Författare

Hanna Rydberg

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Nils Carlsson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Bengt Nordén

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Biochemical and Biophysical Research Communications

0006-291X (ISSN) 1090-2104 (eISSN)

Vol. 427 261-265

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Livsvetenskaper och teknik

Materialvetenskap

Ämneskategorier

Biokemi och molekylärbiologi

DOI

10.1016/j.bbrc.2012.09.030