Abstract
In light chain amyloidosis (AL), fibrillar deposition of monoclonal immunoglobulin light chains (LCs) in vital organs, such as heart, is associated with their severe dysfunction. In addition to the cellular damage caused by fibril deposition, direct toxicity of soluble prefibrillar amyloidogenic proteins has been reported, in particular, for cardiotoxicity. However, the molecular bases of proteotoxicity by soluble LCs have not been clarified. Here, to address this issue, we rationally engineered the amino acid sequence of the highly cardiotoxic LC H6 by introducing three residue mutations, designed to reduce the dynamics of its native state. The resulting mutant (mH6) is less toxic than its parent H6 to human cardiac fibroblasts and C. elegans. The high sequence and structural similarity, together with the different toxicity, make H6 and its non-toxic designed variant mH6 a test case to shed light on the molecular properties underlying soluble toxicity. Our comparative structural and biochemical study of H6 and mH6 shows closely matching crystal structures, whereas spectroscopic data and limited proteolysis indicate that H6 displays poorly cooperative fold, higher flexibility, and kinetic instability, and a higher dynamic state in its native fold. Taken together, the results of this study show a strong correlation between the overall conformational properties of the native fold and the proteotoxicity of cardiotropic LCs.
| Original language | English |
|---|---|
| Journal | Journal of Molecular Biology |
| DOIs | |
| Publication status | Accepted/In press - Jan 1 2019 |
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Keywords
- fold stability
- light chain amyloidosis
- protein dynamics
- protein structure
- proteotoxicity
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology
Cite this
Inherent Biophysical Properties Modulate the Toxicity of Soluble Amyloidogenic Light Chains. / Maritan, Martina; Romeo, Margherita; Oberti, Luca; Sormanni, Pietro; Tasaki, Masayoshi; Russo, Rosaria; Ambrosetti, Arianna; Motta, Paolo; Rognoni, Paola; Mazzini, Giulia; Barbiroli, Alberto; Palladini, Giovanni; Vendruscolo, Michele; Diomede, Luisa; Bolognesi, Martino; Merlini, Giampaolo; Lavatelli, Francesca; Ricagno, Stefano.
In: Journal of Molecular Biology, 01.01.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Inherent Biophysical Properties Modulate the Toxicity of Soluble Amyloidogenic Light Chains
AU - Maritan, Martina
AU - Romeo, Margherita
AU - Oberti, Luca
AU - Sormanni, Pietro
AU - Tasaki, Masayoshi
AU - Russo, Rosaria
AU - Ambrosetti, Arianna
AU - Motta, Paolo
AU - Rognoni, Paola
AU - Mazzini, Giulia
AU - Barbiroli, Alberto
AU - Palladini, Giovanni
AU - Vendruscolo, Michele
AU - Diomede, Luisa
AU - Bolognesi, Martino
AU - Merlini, Giampaolo
AU - Lavatelli, Francesca
AU - Ricagno, Stefano
PY - 2019/1/1
Y1 - 2019/1/1
N2 - In light chain amyloidosis (AL), fibrillar deposition of monoclonal immunoglobulin light chains (LCs) in vital organs, such as heart, is associated with their severe dysfunction. In addition to the cellular damage caused by fibril deposition, direct toxicity of soluble prefibrillar amyloidogenic proteins has been reported, in particular, for cardiotoxicity. However, the molecular bases of proteotoxicity by soluble LCs have not been clarified. Here, to address this issue, we rationally engineered the amino acid sequence of the highly cardiotoxic LC H6 by introducing three residue mutations, designed to reduce the dynamics of its native state. The resulting mutant (mH6) is less toxic than its parent H6 to human cardiac fibroblasts and C. elegans. The high sequence and structural similarity, together with the different toxicity, make H6 and its non-toxic designed variant mH6 a test case to shed light on the molecular properties underlying soluble toxicity. Our comparative structural and biochemical study of H6 and mH6 shows closely matching crystal structures, whereas spectroscopic data and limited proteolysis indicate that H6 displays poorly cooperative fold, higher flexibility, and kinetic instability, and a higher dynamic state in its native fold. Taken together, the results of this study show a strong correlation between the overall conformational properties of the native fold and the proteotoxicity of cardiotropic LCs.
AB - In light chain amyloidosis (AL), fibrillar deposition of monoclonal immunoglobulin light chains (LCs) in vital organs, such as heart, is associated with their severe dysfunction. In addition to the cellular damage caused by fibril deposition, direct toxicity of soluble prefibrillar amyloidogenic proteins has been reported, in particular, for cardiotoxicity. However, the molecular bases of proteotoxicity by soluble LCs have not been clarified. Here, to address this issue, we rationally engineered the amino acid sequence of the highly cardiotoxic LC H6 by introducing three residue mutations, designed to reduce the dynamics of its native state. The resulting mutant (mH6) is less toxic than its parent H6 to human cardiac fibroblasts and C. elegans. The high sequence and structural similarity, together with the different toxicity, make H6 and its non-toxic designed variant mH6 a test case to shed light on the molecular properties underlying soluble toxicity. Our comparative structural and biochemical study of H6 and mH6 shows closely matching crystal structures, whereas spectroscopic data and limited proteolysis indicate that H6 displays poorly cooperative fold, higher flexibility, and kinetic instability, and a higher dynamic state in its native fold. Taken together, the results of this study show a strong correlation between the overall conformational properties of the native fold and the proteotoxicity of cardiotropic LCs.
KW - fold stability
KW - light chain amyloidosis
KW - protein dynamics
KW - protein structure
KW - proteotoxicity
UR - http://www.scopus.com/inward/record.url?scp=85077166510&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85077166510&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2019.12.015
DO - 10.1016/j.jmb.2019.12.015
M3 - Article
AN - SCOPUS:85077166510
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
ER -