Direct characterization of amyloidogenic oligomers by single-molecule fluorescence Export

@article{citeulike:3295156, abstract = {A key issue in understanding the pathogenic conditions associated with the aberrant aggregation of misfolded proteins is the identification and characterization of species formed during the aggregation process. Probing the nature of such species has, however, proved to be extremely challenging to conventional techniques because of their transient and heterogeneous character. We describe here the application of a two-color single-molecule fluorescence technique to examine the assembly of oligomeric species formed during the aggregation of the SH3 domain of PI3 kinase. The single-molecule experiments show that the species formed at the stage of the reaction where aggregates have previously been found to be maximally cytotoxic are a heterogeneous ensemble of oligomers with a median size of 38 ± 10 molecules. This number is remarkably similar to estimates from bulk measurements of the critical size of species observed to seed ordered fibril formation and of the most infective form of prion particles. Moreover, although the size distribution of the SH3 oligomers remains virtually constant as the time of aggregation increases, their stability increases substantially. These findings together provide direct evidence for a general mechanism of amyloid aggregation in which the stable cross-β structure emerges via internal reorganization of disordered oligomers formed during the lag phase of the self-assembly reaction.}, author = {Orte, Angel and Birkett, Neil R. and Clarke, Richard W. and Devlin, Glyn L. and Dobson, Christopher M. and Klenerman, David}, citeulike-article-id = {3295156}, citeulike-linkout-0 = {http://www.pnas.org/content/early/2008/09/15/0803086105.abstract?sid=796cd305-ac09-4bd3-a8d7-dbf7c99257b2}, day = {23}, journal = {Proceedings of the National Academy of Sciences}, keywords = {amyloid, fluorescence, single-molecule}, month = {September}, number = {38}, pages = {14424--14429}, posted-at = {2008-09-19 19:47:04}, priority = {0}, title = {Direct characterization of amyloidogenic oligomers by single-molecule fluorescence}, url = {http://www.pnas.org/content/early/2008/09/15/0803086105.abstract?sid=796cd305-ac09-4bd3-a8d7-dbf7c99257b2}, volume = {105}, year = {2008} }

TY - JOUR ID - citeulike:3295156 L3 - citeulike-article-id:3295156 N2 - A key issue in understanding the pathogenic conditions associated with the aberrant aggregation of misfolded proteins is the identification and characterization of species formed during the aggregation process. Probing the nature of such species has, however, proved to be extremely challenging to conventional techniques because of their transient and heterogeneous character. We describe here the application of a two-color single-molecule fluorescence technique to examine the assembly of oligomeric species formed during the aggregation of the SH3 domain of PI3 kinase. The single-molecule experiments show that the species formed at the stage of the reaction where aggregates have previously been found to be maximally cytotoxic are a heterogeneous ensemble of oligomers with a median size of 38 ± 10 molecules. This number is remarkably similar to estimates from bulk measurements of the critical size of species observed to seed ordered fibril formation and of the most infective form of prion particles. Moreover, although the size distribution of the SH3 oligomers remains virtually constant as the time of aggregation increases, their stability increases substantially. These findings together provide direct evidence for a general mechanism of amyloid aggregation in which the stable cross-β structure emerges via internal reorganization of disordered oligomers formed during the lag phase of the self-assembly reaction. IS - 38 JF - Proceedings of the National Academy of Sciences EP - 14429 TI - Direct characterization of amyloidogenic oligomers by single-molecule fluorescence VL - 105 SP - 14424 KW - amyloid KW - fluorescence KW - single-molecule AU - Orte, Angel AU - Birkett, Neil AU - Clarke, Richard AU - Devlin, Glyn AU - Dobson, Christopher AU - Klenerman, David PY - 2008/09/23/ UR - http://www.pnas.org/content/early/2008/09/15/0803086105.abstract?sid=796cd305-ac09-4bd3-a8d7-dbf7c99257b2 ER -