Please use this identifier to cite or link to this item: https://doi.org/10.1371/journal.pone.0009384
Title: HAMLET interacts with lipid membranes and perturbs their structure and integrity
Authors: Mossberg A.-K.
Puchades M.
Halskau Ø.
Baumann A.
Lanekoff I.
Chao Y. 
Martinez A.
Svanborg C.
Karlsson R.
Keywords: alanine
cysteine
fatty acid
membrane protein
protein hamlet
unclassified drug
lactalbumin
membrane lipid
oleic acid
article
binding affinity
bioaccumulation
fluorescence
human
human cell
internalization
lipid bilayer
lipid composition
lipid membrane
lipid vesicle
membrane fluidity
membrane structure
membrane vesicle
morphology
pH
protein lipid interaction
surface plasmon resonance
tumor cell
animal
apoptosis
binding competition
cell membrane
cell strain
chemistry
confocal microscopy
genetics
hamster
kinetics
lipid bilayer
metabolism
mutation
protein folding
rat
tumor cell line
Animals
Apoptosis
Binding, Competitive
Cell Line, Tumor
Cell Membrane
Cricetinae
Humans
Hydrogen-Ion Concentration
Kinetics
Lactalbumin
Lipid Bilayers
Membrane Lipids
Membrane Microdomains
Microscopy, Confocal
Mutation
Oleic Acid
PC12 Cells
Protein Folding
Rats
Surface Plasmon Resonance
Issue Date: 2010
Citation: Mossberg A.-K., Puchades M., Halskau Ø., Baumann A., Lanekoff I., Chao Y., Martinez A., Svanborg C., Karlsson R. (2010). HAMLET interacts with lipid membranes and perturbs their structure and integrity. PLoS ONE 5 (2) : e9384. ScholarBank@NUS Repository. https://doi.org/10.1371/journal.pone.0009384
Abstract: Background: Cell membrane interactions rely on lipid bilayer constituents and molecules inserted within the membrane, including specific receptors. HAMLET (human ?-lactalbumin made lethal to tumor cells) is a tumoricidal complex of partially unfolded ?-lactalbumin (HLA) and oleic acid that is internalized by tumor cells, suggesting that interactions with the phospholipid bilayer and/or specific receptors may be essential for the tumoricidal effect. This study examined whether HAMLET interacts with artificial membranes and alters membrane structure. Methodology/Principal Findings: We show by surface plasmon resonance that HAMLET binds with high affinity to surface adherent, unilamellar vesicles of lipids with varying acyl chain composition and net charge. Fluorescence imaging revealed that HAMLET accumulates in membranes of vesicles and perturbs their structure, resulting in increased membrane fluidity. Furthermore, HAMLET disrupted membrane integrity at neutral pH and physiological conditions, as shown by fluorophore leakage experiments. These effects did not occur with either native HLA or a constitutively unfolded Cys-Ala HLA mutant (rHLAall-Ala). HAMLET also bound to plasma membrane vesicles formed from intact tumor cells, with accumulation in certain membrane areas, but the complex was not internalized by these vesicles or by the synthetic membrane vesicles. Conclusions/Significance: The results illustrate the difference in membrane affinity between the fatty acid bound and fatty acid free forms of partially unfolded HLA and suggest that HAMLET engages membranes by a mechanism requiring both the protein and the fatty acid. Furthermore, HAMLET binding alters the morphology of the membrane and compromises its integrity, suggesting that membrane perturbation could be an initial step in inducing cell death. © 2010 Mossberg et al.
Source Title: PLoS ONE
URI: https://scholarbank.nus.edu.sg/handle/10635/161816
ISSN: 19326203
DOI: 10.1371/journal.pone.0009384
Appears in Collections:Elements
Staff Publications

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
10_1371_journal_pone_0009384.pdf613.79 kBAdobe PDF

OPEN

NoneView/Download

SCOPUSTM   
Citations

57
checked on Sep 13, 2020

Page view(s)

77
checked on Sep 18, 2020

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.