The use of fluoresceinphosphatidylethanolamine (FPE) as a real-time probe for peptide-membrane interactions.
The characterization of fluoresceinphosphatidylethanolamine (FPE) as a real-time indicator of the electrostatic nature of a membrane surface is described. The conditions appropriate for the labelling of membranes and the implementation of FPE as a tool to monitor the interactions of various peptides with model membranes are outlined. It is shown that of the membrane-active peptides studied, Naja naja kaouthia cardiotoxin and pyrularia thionin bind to certain model membranes without insertion. Whereas the leader sequence of the nuclear encoded subunit IV of mammalian cytochrome c oxidase (E.C. 1.9.3.1), known as p-25, and melittin appear to bind and then partially insert into the membrane. It seems evident also that melittin does not adopt a fully transmembrane configuration. Melittin is known to promote membrane lysis and by employing a rapid-kinetic technique it is shown that the time-course of such lysis does not appear to correlate with peptide binding, but following binding a significant proportion of melittin must become inserted into the membrane before lysis appears to commence.
Wall
J
J
Department of Chemistry & Biological Chemistry, University of Essex, Colchester, UK.
Golding
C A
CA
Van Veen
M
M
O'Shea
P
P
D000595:Amino Acid Sequence; D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D004179:Cobra Cardiotoxin Proteins / Q000378:metabolism; D004563:Electrochemistry; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008555:Melitten / Q000378:metabolism; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry; D015335:Molecular Probes; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000737:chemistry* / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014118:Toxins, Biological / Q000378:metabolism
D004179:Cobra Cardiotoxin Proteins; D008081:Liposomes; D008563:Membrane Lipids; D008565:Membrane Proteins; D015335:Molecular Probes; D009842:Oligopeptides; D010712:Phosphatidic Acids; D010743:Phospholipids; D010940:Plant Proteins; D014118:Toxins, Biological; C063389:fluorescein phosphatidylethanolamine thiocarbamide; D008555:Melitten; D003576:Electron Transport Complex IV