The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
David Eisenberg - One of the best experts on this subject based on the ideXlab platform.
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beta subsccript 2 microglobulin forms three Dimensional Domain swapped amyloid fibrils with disulfide linkages
Nature Structural & Molecular Biology, 2011Co-Authors: Michael R Sawaya, David EisenbergAbstract:{beta}{sub 2}-microglobulin ({beta}{sub 2}-m) is the light chain of the type I major histocompatibility complex. It deposits as amyloid fibrils within joints during long-term hemodialysis treatment. Despite the devastating effects of dialysis-related amyloidosis, full understanding of how fibrils form from soluble {beta}{sub 2}-m remains elusive. Here we show that {beta}{sub 2}-m can oligomerize and fibrillize via three-Dimensional Domain swapping. Isolating a covalently bound, Domain-swapped dimer from {beta}{sub 2}-m oligomers on the pathway to fibrils, we were able to determine its crystal structure. The hinge loop that connects the swapped Domain to the core Domain includes the fibrillizing segment LSFSKD, whose atomic structure we also determined. The LSFSKD structure reveals a class 5 steric zipper, akin to other amyloid spines. The structures of the dimer and the zipper spine fit well into an atomic model for this fibrillar form of {beta}{sub 2}-m, which assembles slowly under physiological conditions.
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β 2 microglobulin forms three Dimensional Domain swapped amyloid fibrils with disulfide linkages
Nature Structural & Molecular Biology, 2011Co-Authors: Cong Liu, Michael R Sawaya, David EisenbergAbstract:β2-microglobulin can form different forms of amyloid fibrils within joints of dialysis patients. Now the crystal structures of a β2m Domain swapped dimer and of the steric zipper formed by a short peptide indicate how these fibrils might form.
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recent atomic models of amyloid fibril structure
Current Opinion in Structural Biology, 2006Co-Authors: Rebecca Nelson, David EisenbergAbstract:Despite the difficulties associated with determining atomic-level structures for materials that are fibrous, structural biologists are making headway in understanding the architecture of amyloid-like fibrils. It has long been recognized that these fibrils contain a cross-β spine, with β-strands perpendicular to the fibril axis. Recently, atomic structures have been determined for some of these cross-β spines, revealing a pair of β-sheets mated closely together by intermeshing sidechains in what has been termed a steric zipper. To explain the conversion of proteins from soluble to fibrous forms, several types of models have been proposed: refolding, natively disordered and gain of interaction. The gain-of-interaction models may additionally be subdivided into direct stacking, cross-β spine, three-Dimensional Domain swapping and three-Dimensional Domain swapping with a cross-β spine.
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Amyloid-like fibrils of ribonuclease A with three-Dimensional Domain-swapped and native-like structure
Nature, 2005Co-Authors: Shilpa Sambashivan, Michael R Sawaya, Yanshun Liu, Mari Gingery, David EisenbergAbstract:The prospects of limiting the spread of transmissible spongiform encephalopathies such as Creutzfeldt–Jakob disease depend in part on identifying the most infectious forms of the prions that carry the diseases. A study of modified scrapie prions shows that clusters of 14 to 28 prion proteins are the most infectious and that clusters of less than six molecules have virtually no infectivity. That could have implications for the treatment of diseases such as Alzheimer's and Parkinson's, characterized by deposition of prion-related amyloid fibrils. It's possible that efforts to alleviate symptoms by destabilizing these large protein aggregates might make things worse by producing smaller, more infective particles. Two other papers in this issue tackle fundamental aspects of the biology of prions and amyloid fibrils. The conversion of the yeast protein Sup35 to its prion form does not need to happen during the synthesis of Sup35 — mature and fully functional molecules can readily join a prion seed. This remodelling of the mature protein is accompanied by the immediate loss of its activity. And a study of a ‘designed’ amyloid fibril made from ribonuclease A reveals that amyloid containing native-like molecules can retain enzyme activity. This involves a Domain swap with the neighbouring protein, and supports the ‘zipper-spine model’ for β-amyloid structures. Amyloid or amyloid-like fibrils are elongated, insoluble protein aggregates, formed in vivo ^ 1 in association with neurodegenerative diseases or in vitro ^ 2 from soluble native proteins, respectively. The underlying structure of the fibrillar or ‘cross-β’ state has presented long-standing, fundamental puzzles of protein structure. These include whether fibril-forming proteins have two structurally distinct stable states, native and fibrillar, and whether all or only part of the native protein refolds as it converts to the fibrillar state. Here we show that a designed amyloid-like fibril of the well-characterized enzyme RNase A contains native-like molecules capable of enzymatic activity. In addition, these functional molecular units are formed from a core RNase A Domain and a swapped complementary Domain. These findings are consistent with the zipper-spine model^ 3 in which a cross-β spine is decorated with three-Dimensional Domain-swapped functional units, retaining native-like structure.
Michael R Sawaya - One of the best experts on this subject based on the ideXlab platform.
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beta subsccript 2 microglobulin forms three Dimensional Domain swapped amyloid fibrils with disulfide linkages
Nature Structural & Molecular Biology, 2011Co-Authors: Michael R Sawaya, David EisenbergAbstract:{beta}{sub 2}-microglobulin ({beta}{sub 2}-m) is the light chain of the type I major histocompatibility complex. It deposits as amyloid fibrils within joints during long-term hemodialysis treatment. Despite the devastating effects of dialysis-related amyloidosis, full understanding of how fibrils form from soluble {beta}{sub 2}-m remains elusive. Here we show that {beta}{sub 2}-m can oligomerize and fibrillize via three-Dimensional Domain swapping. Isolating a covalently bound, Domain-swapped dimer from {beta}{sub 2}-m oligomers on the pathway to fibrils, we were able to determine its crystal structure. The hinge loop that connects the swapped Domain to the core Domain includes the fibrillizing segment LSFSKD, whose atomic structure we also determined. The LSFSKD structure reveals a class 5 steric zipper, akin to other amyloid spines. The structures of the dimer and the zipper spine fit well into an atomic model for this fibrillar form of {beta}{sub 2}-m, which assembles slowly under physiological conditions.
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β 2 microglobulin forms three Dimensional Domain swapped amyloid fibrils with disulfide linkages
Nature Structural & Molecular Biology, 2011Co-Authors: Cong Liu, Michael R Sawaya, David EisenbergAbstract:β2-microglobulin can form different forms of amyloid fibrils within joints of dialysis patients. Now the crystal structures of a β2m Domain swapped dimer and of the steric zipper formed by a short peptide indicate how these fibrils might form.
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Amyloid-like fibrils of ribonuclease A with three-Dimensional Domain-swapped and native-like structure
Nature, 2005Co-Authors: Shilpa Sambashivan, Michael R Sawaya, Yanshun Liu, Mari Gingery, David EisenbergAbstract:The prospects of limiting the spread of transmissible spongiform encephalopathies such as Creutzfeldt–Jakob disease depend in part on identifying the most infectious forms of the prions that carry the diseases. A study of modified scrapie prions shows that clusters of 14 to 28 prion proteins are the most infectious and that clusters of less than six molecules have virtually no infectivity. That could have implications for the treatment of diseases such as Alzheimer's and Parkinson's, characterized by deposition of prion-related amyloid fibrils. It's possible that efforts to alleviate symptoms by destabilizing these large protein aggregates might make things worse by producing smaller, more infective particles. Two other papers in this issue tackle fundamental aspects of the biology of prions and amyloid fibrils. The conversion of the yeast protein Sup35 to its prion form does not need to happen during the synthesis of Sup35 — mature and fully functional molecules can readily join a prion seed. This remodelling of the mature protein is accompanied by the immediate loss of its activity. And a study of a ‘designed’ amyloid fibril made from ribonuclease A reveals that amyloid containing native-like molecules can retain enzyme activity. This involves a Domain swap with the neighbouring protein, and supports the ‘zipper-spine model’ for β-amyloid structures. Amyloid or amyloid-like fibrils are elongated, insoluble protein aggregates, formed in vivo ^ 1 in association with neurodegenerative diseases or in vitro ^ 2 from soluble native proteins, respectively. The underlying structure of the fibrillar or ‘cross-β’ state has presented long-standing, fundamental puzzles of protein structure. These include whether fibril-forming proteins have two structurally distinct stable states, native and fibrillar, and whether all or only part of the native protein refolds as it converts to the fibrillar state. Here we show that a designed amyloid-like fibril of the well-characterized enzyme RNase A contains native-like molecules capable of enzymatic activity. In addition, these functional molecular units are formed from a core RNase A Domain and a swapped complementary Domain. These findings are consistent with the zipper-spine model^ 3 in which a cross-β spine is decorated with three-Dimensional Domain-swapped functional units, retaining native-like structure.
Konstantin Y Guslienko - One of the best experts on this subject based on the ideXlab platform.
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steady one Dimensional Domain wall motion in biaxial ferromagnets mapping of the landau lifshitz equation to the sine gordon equation
Physical Review B, 2020Co-Authors: R Ramaeiroa, R M Otxoa, P E Roy, Konstantin Y GuslienkoAbstract:Motivated by the difference between the dynamics of magnetization textures in ferromagnets and antiferromagnets, the Landau-Lifshitz equation of motion is explored. A typical one-Dimensional Domain wall in a bulk ferromagnet with biaxial magnetic anisotropy is considered. In the framework of Walker-type solutions of steady-state ferromagnetic Domain wall motion, the reduction of the nonlinear Landau-Lifshitz equation to a Lorentz-invariant sine-Gordon equation typical for antiferromagnets is formally possible for velocities lower than a critical velocity of the topological soliton. The velocity dependence of the Domain wall energy and the Domain wall width are expressed in the relativistic-like form in the limit of large ratio of the easy-plane/easy-axis anisotropy constants. It is shown that the mapping of the Landau-Lifshitz equation of motion to the sine-Gordon equation can be performed only by going beyond the steady-motion Walker-type solutions.
R Ramaeiroa - One of the best experts on this subject based on the ideXlab platform.
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steady one Dimensional Domain wall motion in biaxial ferromagnets mapping of the landau lifshitz equation to the sine gordon equation
Physical Review B, 2020Co-Authors: R Ramaeiroa, R M Otxoa, P E Roy, Konstantin Y GuslienkoAbstract:Motivated by the difference between the dynamics of magnetization textures in ferromagnets and antiferromagnets, the Landau-Lifshitz equation of motion is explored. A typical one-Dimensional Domain wall in a bulk ferromagnet with biaxial magnetic anisotropy is considered. In the framework of Walker-type solutions of steady-state ferromagnetic Domain wall motion, the reduction of the nonlinear Landau-Lifshitz equation to a Lorentz-invariant sine-Gordon equation typical for antiferromagnets is formally possible for velocities lower than a critical velocity of the topological soliton. The velocity dependence of the Domain wall energy and the Domain wall width are expressed in the relativistic-like form in the limit of large ratio of the easy-plane/easy-axis anisotropy constants. It is shown that the mapping of the Landau-Lifshitz equation of motion to the sine-Gordon equation can be performed only by going beyond the steady-motion Walker-type solutions.
Shilpa Sambashivan - One of the best experts on this subject based on the ideXlab platform.
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Amyloid-like fibrils of ribonuclease A with three-Dimensional Domain-swapped and native-like structure
Nature, 2005Co-Authors: Shilpa Sambashivan, Michael R Sawaya, Yanshun Liu, Mari Gingery, David EisenbergAbstract:The prospects of limiting the spread of transmissible spongiform encephalopathies such as Creutzfeldt–Jakob disease depend in part on identifying the most infectious forms of the prions that carry the diseases. A study of modified scrapie prions shows that clusters of 14 to 28 prion proteins are the most infectious and that clusters of less than six molecules have virtually no infectivity. That could have implications for the treatment of diseases such as Alzheimer's and Parkinson's, characterized by deposition of prion-related amyloid fibrils. It's possible that efforts to alleviate symptoms by destabilizing these large protein aggregates might make things worse by producing smaller, more infective particles. Two other papers in this issue tackle fundamental aspects of the biology of prions and amyloid fibrils. The conversion of the yeast protein Sup35 to its prion form does not need to happen during the synthesis of Sup35 — mature and fully functional molecules can readily join a prion seed. This remodelling of the mature protein is accompanied by the immediate loss of its activity. And a study of a ‘designed’ amyloid fibril made from ribonuclease A reveals that amyloid containing native-like molecules can retain enzyme activity. This involves a Domain swap with the neighbouring protein, and supports the ‘zipper-spine model’ for β-amyloid structures. Amyloid or amyloid-like fibrils are elongated, insoluble protein aggregates, formed in vivo ^ 1 in association with neurodegenerative diseases or in vitro ^ 2 from soluble native proteins, respectively. The underlying structure of the fibrillar or ‘cross-β’ state has presented long-standing, fundamental puzzles of protein structure. These include whether fibril-forming proteins have two structurally distinct stable states, native and fibrillar, and whether all or only part of the native protein refolds as it converts to the fibrillar state. Here we show that a designed amyloid-like fibril of the well-characterized enzyme RNase A contains native-like molecules capable of enzymatic activity. In addition, these functional molecular units are formed from a core RNase A Domain and a swapped complementary Domain. These findings are consistent with the zipper-spine model^ 3 in which a cross-β spine is decorated with three-Dimensional Domain-swapped functional units, retaining native-like structure.