Inhibition of amyloid aggregation of bovine serum albumin by sodium dodecyl sulfate at submicellar concentrations

Abstract

Sodium dodecyl sulfate (SDS), as an anionic surfactant, can induce protein conformational changes. Recent investigations demonstrated different effects of SDS on protein amyloid aggregation. In the present study, the effect of SDS on amyloid aggregation of bovine serum albumin (BSA) was evaluated. BSA transformed to β-sheet-rich amyloid aggregates upon incubation at pH 7.4 and 65°C, as demonstrated by thioflavin T fluorescence, circular dichroism, and transmission electron microscopy. SDS at submicellar concentrations inhibited BSA amyloid aggregation with IC of 47.5 µM. The inhibitory effects of structural analogs of SDS on amyloid aggregation of BSA were determined to explore the structure-activity relationship, with results suggesting that both anionic and alkyl moieties of SDS were critical, and that an alkyl moiety with chain length ≥10 carbon atoms was essential to amyloid inhibition. We attributed the inhibitory effect of SDS on BSA amyloid aggregation to interactions between the detergent molecule and the fatty acid binding sites on BSA. The bound SDS stabilized BSA, thereby inhibiting protein transformation to amyloid aggregates. This study reports for the first time that the inhibitory effect of SDS on albumin fibrillation is closely related to its alkyl structure. Moreover, the specific binding of SDS to albumin is the main driving force in amyloid inhibition. This study not only provides fresh insight into the role of SDS in amyloid aggregation of serum albumin, but also suggests rational design of novel anti-amyloidogenic reagents based on specific-binding ligands.

Laccase-catalyzed cross-linking of BSA mediated by tyrosine

“…3(b)) and their molar ellipticity values were declined due to the decreasing of α-helix content. The results were consistent with FTIR analysis and other reports about BSA treated with metal ions [53,54] or chemical reagent [55][56][57]. The secondary structure contents of each sample were calculated and shown in Table 3.…”

Molecular Interaction of Protein-Pigment C-Phycocyanin with Bovine Serum Albumin in a Gomphosis Structure Inhibiting Amyloid Formation

“…The inhibitory assay was designed according to the previous method [37] using Tecan Infinite M200 Pro microplate reader (Männedorf, Switzerland). The final volume of the reaction system was 1000 µL, containing BSA (0.1 mM, 50 µL) and various volumes of C-phycocyanin (1 mg/mL).…”

Identification of Amyloidogenic Regions in Pseudomonas aeruginosa Ribosomal S1 Protein

“…In the present work, amyloidogenic fragments were identified in the amino acid sequence of bPaS1, using the programs for searching and predicting amyloidogenic regions FoldAmyloid [ 38 ], Waltz [ 39 ], Pasta 2.0 [ 40 ] and AGGRESCAN [ 41 ], and experimentally by analyzing the products of limited proteolysis of bPaS1 aggregates using high performance liquid chromatography and mass spectrometry (LC-MS). The tendency to amyloid formation of peptides synthesized on the basis of amyloidogenic regions of bPaS1 was studied by electron microscopy (EM) and fluorescence spectroscopy (using thioflavin T (ThT)), which are widely used to detect amyloids [ 42 , 43 , 44 ].…”