کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1944458 1053211 2012 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A yeast toxic mutant of HET-s amyloid disrupts membrane integrity
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
A yeast toxic mutant of HET-s amyloid disrupts membrane integrity
چکیده انگلیسی

Many studies have pointed out the interaction between amyloids and membranes, and their potential involvement in amyloid toxicity. Previously, we generated a yeast toxic amyloid mutant (M8) from the harmless amyloid protein by changing a few residues of the Prion Forming Domain of HET-s (PFD HET-s218–289) and clearly demonstrated the complete different behaviors of the non-toxic Wild Type (WT) and toxic amyloid (called M8) in terms of fiber morphology, aggregation kinetics and secondary structure. In this study, we compared the interaction of both proteins (WT and M8) with membrane models, as liposomes or supported bilayers. We first demonstrated that the toxic protein (M8) induces a significant leakage of liposomes formed with negatively charged lipids and promotes the formation of microdomains inside the lipid bilayer (as potential “amyloid raft”), whereas the non-toxic amyloid (WT) only binds to the membrane without further perturbations. The secondary structure of both amyloids interacting with membrane is preserved, but the anti-symmetric PO2− vibration is strongly shifted in the presence of M8. Secondly, we established that the presence of membrane models catalyzes the amyloidogenesis of both proteins. Cryo-TEM (cryo‐transmission electron microscopy) images show the formation of long HET-s fibers attached to liposomes, whereas a large aggregation of the toxic M8 seems to promote a membrane disruption. This study allows us to conclude that the toxicity of the M8 mutant could be due to its high propensity to interact and disrupt lipid membranes.


► Toxic amyloid promotes the formation of “raft”-like microdomains inside the lipid bilayer.
► The non-toxic amyloid only binds to the membrane without strong perturbations.
► For both proteins, the presence of membrane models catalyzes the amyloidogenesis.
► In interaction with membrane the secondary structure of both amyloids is not affected.
► The toxic amyloid induces a strong variation of the phosphate groups of the lipid.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1818, Issue 9, September 2012, Pages 2325–2334
نویسندگان
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