Residual structures in the acid-unfolded states of Vlambda6 proteins affect amyloid fibrillation
| Autor: | Takaaki Kanemaru, Akira Monji, Yoshito Abe, Takatoshi Ohkuri, Tadashi Ueda, Tomonori Mishima |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Amyloid
Protein Folding Molecular Sequence Data macromolecular substances Fibril Protein Structure Secondary chemistry.chemical_compound Protein structure Immunoglobulin lambda-Chains Structural Biology Humans Amino Acid Sequence Molecular Biology Peptide sequence chemistry.chemical_classification Sequence Homology Amino Acid Chemistry Protein Stability Wild type Hydrogen-Ion Concentration Recombinant Proteins Amino acid Biochemistry Lysozyme Acids Heteronuclear single quantum coherence spectroscopy |
| Zdroj: | Journal of molecular biology. 392(4) |
| ISSN: | 1089-8638 |
| Popis: | Many proteins form amyloid-like fibrils in vitro under partially or highly unfolding conditions. Recently, we showed that the residual structure in highly unfolded state is closely related to amyloid fibril formation in hen lysozyme. Thus, to better understand the role of the residual structure on amyloid fibril formation, we focused on AL amyloidosis, which results from the extracellular deposition of monoclonal immunoglobulin light-chain variable domains (V(L)s) as insoluble fibrils. We examined the relationship between the residual structure and amyloid fibril formation on three lambda6 recombinant V(L) (rVlambda6) proteins, wild type, Jto, and Wil. Although rVlambda6 proteins are highly unfolded in pH 2, (15)N NMR transverse relaxation experiments revealed nonrandom structures in regions, which include some hydrophobic residues and a single disulfide bond, indicating the existence of residual structure in rVlambda6 proteins. However, the residual structure of Wil was markedly disrupted compared with those of the other proteins, despite there being no significant differences in amino acid sequences. Fibrillation experiments revealed that Wil had a longer lag time for fibril formation than the others. When the single disulfide bond was reduced and alkylated, the residual structure was largely disrupted and fibril formation was delayed in all three rVlambda6 proteins. It was suggested that the residual structure in highly unfolded state has a crucial role in amyloid fibril formation in many proteins, even pathogenic ones. |
| Databáze: | OpenAIRE |
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