TY - JOUR
T1 - Monitoring the process of HypF fibrillization and liposome permeabilization by protofibrils
AU - Relini, Annalisa
AU - Torrassa, Silvia
AU - Rolandi, Ranieri
AU - Gliozzi, Alessandra
AU - Rosano, Camillo
AU - Canale, Claudio
AU - Bolognesi, Martino
AU - Plakoutsi, Georgia
AU - Bucciantini, Monica
AU - Chiti, Fabrizio
AU - Stefani, Massimo
PY - 2004/5/14
Y1 - 2004/5/14
N2 - Much information has appeared in the last few years on the low resolution structure of amyloid fibrils and on their non-fibrillar precursors formed by a number of proteins and peptides associated with amyloid diseases. The fine structure and the dynamics of the process leading misfolded molecules to aggregate into amyloid assemblies are far from being fully understood. Evidence has been provided in the last five years that protein aggregation and aggregate toxicity are rather generic processes, possibly affecting all polypeptide chains under suitable experimental conditions. This evidence extends the number of model proteins one can investigate to assess the molecular bases and general features of protein aggregation and aggregate toxicity. We have used tapping mode atomic force microscopy to investigate the morphological features of the pre-fibrillar aggregates and of the mature fibrils produced by the aggregation of the hydrogenase maturation factor HypF N-terminal domain (HypF-N), a protein not associated to any amyloid disease. We have also studied the aggregate-induced permeabilization of liposomes by fluorescence techniques. Our results show that HypF-N aggregation follows a hierarchical path whereby initial globules assemble into crescents; these generate large rings, which evolve into ribbons, further organizing into differently supercoiled fibrils. The early pre-fibrillar aggregates were shown to be able to permeabilize synthetic phospholipid membranes, thus showing that this disease-unrelated protein displays the same amyloidogenic behaviour found for the aggregates of most pathological proteins and peptides. These data complement previously reported findings, and support the idea that protein aggregation, aggregate structure and toxicity are generic properties of polypeptide chains.
AB - Much information has appeared in the last few years on the low resolution structure of amyloid fibrils and on their non-fibrillar precursors formed by a number of proteins and peptides associated with amyloid diseases. The fine structure and the dynamics of the process leading misfolded molecules to aggregate into amyloid assemblies are far from being fully understood. Evidence has been provided in the last five years that protein aggregation and aggregate toxicity are rather generic processes, possibly affecting all polypeptide chains under suitable experimental conditions. This evidence extends the number of model proteins one can investigate to assess the molecular bases and general features of protein aggregation and aggregate toxicity. We have used tapping mode atomic force microscopy to investigate the morphological features of the pre-fibrillar aggregates and of the mature fibrils produced by the aggregation of the hydrogenase maturation factor HypF N-terminal domain (HypF-N), a protein not associated to any amyloid disease. We have also studied the aggregate-induced permeabilization of liposomes by fluorescence techniques. Our results show that HypF-N aggregation follows a hierarchical path whereby initial globules assemble into crescents; these generate large rings, which evolve into ribbons, further organizing into differently supercoiled fibrils. The early pre-fibrillar aggregates were shown to be able to permeabilize synthetic phospholipid membranes, thus showing that this disease-unrelated protein displays the same amyloidogenic behaviour found for the aggregates of most pathological proteins and peptides. These data complement previously reported findings, and support the idea that protein aggregation, aggregate structure and toxicity are generic properties of polypeptide chains.
KW - amyloid
KW - atomic force microscopy
KW - fibrillization path
KW - HypF-N fibrils
KW - HypF-N, the N-terminal domain of the Escherichia coli hydrogenase maturation factor HypF
KW - membrane permeabilization
KW - ThT, thioflavine T
KW - TM-AFM, tapping mode atomic force microscopy
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U2 - 10.1016/j.jmb.2004.03.054
DO - 10.1016/j.jmb.2004.03.054
M3 - Article
C2 - 15111058
AN - SCOPUS:11144353842
VL - 338
SP - 943
EP - 957
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 5
ER -