Establishment of a kinetic model of dialysis-related amyloid fibril extension<i>in vitro</i>

Naiki, Hironobu; Hashimoto, Norikazu; Suzuki, Satoru; Kimura, Hideki; Nakakuki, Kazuya; Gejyo, Fumitake

doi:10.3109/13506129709003833

Cited by 230 publications

(321 citation statements)

References 18 publications

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“…7 However, long and straight amyloid fibrils resembling those extracted from patients are formed from a precursor state formed at pH 2.5. 8,9 Here, we compare the conformational properties of these two partially unfolded intermediates with single-residue resolution and demonstrate that a close relationship exists between the structure and dynamics of the amyloid precursor species and the morphology of mature fibrils of b2m.At pH 2.5 b2m is highly unfolded, the majority of resonances are observed in 1 H-15 N HSQC spectra (Supporting Information, Figure 1) and can be assigned to individual residues. 10 In contrast, only about 40-60 resolved peaks on top of a broad hump of unresolved signal intensity (visible at lower contour levels) could be observed at pH 3.6 ( Figure 1a).…”

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confidence: 87%

Molten Globule Precursor States Are Conformationally Correlated to Amyloid Fibrils of Human β-2-Microglobulin

2010

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Misfolding intermediates play a key role in defining aberrant protein aggregation and amyloid formation in more than 15 different human diseases. However, their experimental characterization is challenging due to the transient nature and conformational heterogeneity of the involved states. Here, we demonstrate that direct carbon-detected NMR experiments allow observation, assignment, and structural analysis of molten globule amyloid intermediates that are severely broadened by conformational exchange. The method is used to characterize the structure and dynamics of partially unfolded intermediates of the 99-residue protein -2-microglobulin, which is the major component of insoluble aggregates occurring in dialysis-related amyloidosis. Comparison of the conformational properties of the molten globule-like intermediates with levels of deuterium incorporation into amyloid fibrils of -2-microglobulin revealed a close relationship between the conformational properties of the metastable intermediates and the -sheet-rich insoluble aggregates of -2-microglobulin.Misfolding intermediates play a key role in defining aberrant protein aggregation and amyloid formation in more than 15 different human diseases. 1,2 However, the experimental characterization of the conformation of amyloid intermediates is challenging due to their transient nature and conformational heterogeneity. 3,4 This severely limits our knowledge about the relation of the conformation of the precursor states to the structure of amyloid fibrils.Dialysis-related amyloidosis is a protein misfolding disease resulting from deposition of amyloid aggregates in skeletal tissue that contain fibrils of the 99-residue-long protein -2-microglobulin (b2m). 5 Amyloid formation of b2m is strongly enhanced in conditions that destabilize its globular structure. 6 This can be achieved in Vitro by acid denaturation, with two distinct intermediate states being formed under acidic conditions. The highest population of the partially unfolded intermediate occurs at pH 3.6, where also the rate of fibril formation reaches a maximum. 7 However, long and straight amyloid fibrils resembling those extracted from patients are formed from a precursor state formed at pH 2.5. 8,9 Here, we compare the conformational properties of these two partially unfolded intermediates with single-residue resolution and demonstrate that a close relationship exists between the structure and dynamics of the amyloid precursor species and the morphology of mature fibrils of b2m.At pH 2.5 b2m is highly unfolded, the majority of resonances are observed in 1 H-15 N HSQC spectra (Supporting Information, Figure 1) and can be assigned to individual residues. 10 In contrast, only about 40-60 resolved peaks on top of a broad hump of unresolved signal intensity (visible at lower contour levels) could be observed at pH 3.6 ( Figure 1a). 11 To obtain sequence-specific information about the pH 3.6 intermediate, we tested direct 13 C detection. 12-14 Direct carbon detection was previously successfully used fo...

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confidence: 87%

Molten Globule Precursor States Are Conformationally Correlated to Amyloid Fibrils of Human β-2-Microglobulin

2010

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“…After the reaction mixture was prepared in an Eppendorf tube, ultrasonic treatment was started with the tube placed in a water bath-type ultrasonicator (Elekon ELESTEIN 070-GOT) at 37 C. The effects of ultrasonication were monitored by fluorometric analysis with thioflavin T (ThT), a specific dye for amyloid fibrils. 24,30,36) Repeated ultrasonication induced a sudden and remarkable increase of ThT fluorescence after a lag-time of about 120 min [ Fig. 2(a)].…”

Section: Amyloid Fibrillation At Low Phmentioning

confidence: 99%

“…Recently, a mutant 2-m has been found in patients who develop a different type of amyloidosis, giving a novel insight into the pathology of amyloidosis caused by 2-m. 23) In patients receiving hemodialysis, 2-m fibrils deposit under physiological pH conditions. On the other hand, the incubation of 2-m in vitro under acidic conditions results in a relatively rapid fibrillation at high yields, 11,24) indicating that the native conformation prevents the formation of fibrils. Recently, the mechanism of amyloid fibrillation under physiological pH conditions has been focused on.…”

Section: Introductionmentioning

confidence: 99%

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Ultrasonication: An Efficient Agitation for Accelerating the Supersaturation-Limited Amyloid Fibrillation of Proteins

Yoshimura

Yagi

et al. 2013

Jpn. J. Appl. Phys.

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Amyloid fibrils are self-assemblies of proteins with an ordered cross-β architecture. Because they are associated with serious disorders, understanding their structure and mechanism of fibrillation is important. Irradiation with ultrasonication leads to fragmentation of amyloid fibrils, useful for seeding experiments. Recently, ultrasonication has been found to trigger the spontaneous formation of fibrils in solutions of monomeric amyloidogenic proteins. The results indicate that amyloid fibrillation is similar to the crystallization of solutes from a supersaturated solution. The accelerating effects of ultrasonication on amyloid fibrillation suggest that cavitation microbubbles play a key role in effectively converting the metastable state of supersaturation to the labile state, leading to spontaneous fibrillation. Moreover, ultrasonic irradiation would be promising for a high-throughput screening assay of amyloid fibrillation, advancing the study of supersaturation-limited amyloidogenesis.

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“…Once the nucleus is formed, subsequent polymerization proceeds rapidly through the sequential incorporation of precursor molecules into the nucleated fibrils. Many experiments have demonstrated that fibrillation from various proteins involves a lag period that corresponds to the nucleation process before the formation of mature, welldefined amyloid fibrils (Lomakin et al 1996;Naiki et al 1997;Yagi et al 2005;Hamley 2007;Sasahara et al 2008;Xue et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Application and use of differential scanning calorimetry in studies of thermal fluctuation associated with amyloid fibril formation

Sasahara

Goto

2012

Biophys Rev

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The aggregation of proteins into amyloid fibrils is a topic that has attracted great interest because the process is associated with the pathology of numerous human diseases. Despite considerable progress in the elucidation of the structure of amyloid fibrils and the kinetic mechanism of their formation, knowledge on the thermodynamic aspects underlying the formation and stability of amyloid fibrils is limited. In this review, we summarize recent calorimetric studies of amyloid fibril formation, with the goal of obtaining a better understanding of the causal factors that thermally induce proteins to aggregate into amyloid fibrils. Calorimetric data show that differential scanning calorimetry is a useful technique to study the causative factors that thermally trigger the conversion to the amyloid structure and highlight the physics related to the thermal fluctuation of proteins during this conversion.

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Establishment of a kinetic model of dialysis-related amyloid fibril extensionin vitro

Cited by 230 publications

References 18 publications

Molten Globule Precursor States Are Conformationally Correlated to Amyloid Fibrils of Human β-2-Microglobulin

Molten Globule Precursor States Are Conformationally Correlated to Amyloid Fibrils of Human β-2-Microglobulin

Ultrasonication: An Efficient Agitation for Accelerating the Supersaturation-Limited Amyloid Fibrillation of Proteins

Application and use of differential scanning calorimetry in studies of thermal fluctuation associated with amyloid fibril formation

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