JOURNAL ARTICLE

Lipids enhance apolipoprotein C-II-derived amyloidogenic peptide oligomerization but inhibit fibril formation

Andrew Hung, Michael D W Griffin, Geoffrey J Howlett, Irene Yarovsky
Journal of Physical Chemistry. B 2009 July 16, 113 (28): 9447-53
19537801
We investigated the effect of submicellar lipids on amyloid fibril formation. Thioflavin T fluorescence studies showed that submicellar levels of the short-chain phospholipids, dipentanoylphosphatidylcholine and dihexanoylphosphatidylcholine, strongly inhibited amyloid fibril formation by an 11-residue peptide derived from human apolipoprotein C-II (apoC-II(60-70)). In contrast, sedimentation equilibrium analysis of these peptide-lipid mixtures indicated the presence of soluble oligomeric complexes. To acquire insight into the atomic level influences of these lipids on the initial stages of aggregation of the peptide, we performed molecular dynamics (MD) simulations coupled with umbrella sampling to determine dimerization free energies of a number of beta-stranded and random coil dimer complexes, both in the presence and absence of lipids. The simulations indicate that, in contrast to their inhibitory effects on fibril formation, short-chain phospholipids promote the formation and stabilization of dimers by enhancing intersubunit hydrophobic interactions. On the basis of these experimental and computational results, we propose that peptide-bound lipids can inhibit amyloid fibril formation by trapping of dimers and other oligomeric species in diverse nonfibril forming conformations, reducing their likelihood of acquiring subunit conformations prone to fibril nucleation and growth. In light of the demonstrated cytotoxicity of amyloid peptide oligomers, our results suggest that, by enhancing the stability of oligomeric peptide species, the presence of solvated lipids may contribute to the cytotoxicity of fibrillogenic proteins and peptides.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
19537801
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"