The Formation of Amyloid-Like Fibrils of α-Chymotrypsin in Different Aqueous Organic Solvents
| Autor: | Lívia Fülöp, Ilona Laczkó, Anett Demcsák, L. Mária Simon, Dávid Tóth, Márta Kotormán |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Amyloid
Circular dichroism Chymotrypsin Aqueous solution biology Chemistry Circular Dichroism Inorganic chemistry Chemical modification Amyloidogenic Proteins Congo Red General Medicine Fibril Biochemistry Congo red chemistry.chemical_compound Structural Biology Polymer chemistry Solvents biology.protein Dimethylformamide Spectrophotometry Ultraviolet Thioflavin Organic Chemicals |
| Zdroj: | Protein & Peptide Letters. 19:544-550 |
| ISSN: | 0929-8665 |
| DOI: | 10.2174/092986612800191071 |
| Popis: | The formation of amyloid-like fibrils of α-chymotrypsin was studied in aqueous ethanol, methanol, tertbutanol, dimethylformamide and acetonitrile. Thioflavin T (ThT), Congo red (CR) and 1-anilino-8-naphthalenesulfonic acid (ANS) binding, turbidity, intrinsic fluorescence and far-UV circular dichroism measurements were employed to characterize the amyloid fibril formation. The greatest extent of fibril formation after incubation for 24 h at pH 7.0 and at 24 °C was in ethanol at 55%, in methanol and dimethylformamide (DMF) at 60-70% and in tert-butanol at 60-80%. The ANS binding and intrinsic fluorescence results showed that the hydrophobic residues are more solvent-exposed in the aggregated form of α-chymotrypsin. The ThT, CR binding and far-UV CD measurements indicated that the formation of the cross-β structure of α-chymotrypsin depends on the polarity of the organic solvent. To determine the role of surface charges in the aggregation, chemically modified forms of α-chymotrypsin were prepared. The citraconylated and succinylated enzymes exhibited a higher and the enzyme forms modified with aliphatic aldehydes a lower propensity for aggregation. These results suggest the important role of surface charges in the aggregation of α-chymotrypsin. |
| Databáze: | OpenAIRE |
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