title: Inhibiting effect of α(s1)-casein on Aβ(1-40) fibrillogenesis.
abstract: BACKGROUND
  α(s1)-Casein is one of the four types of caseins, the largest protein component of bovine milk. The lack of a compact folded conformation and the capability to form micelles suggest a relationship of α(s1)-casein with the class of the intrinsically disordered (or natively unfolded) proteins. These proteins are known to exert a stabilizing activity on biomolecules through specific interaction with hydrophobic surfaces. In the present work we focused on the effect of α(s1)-casein on the fibrillogenesis of 1-40 β-amyloid peptide, involved in Alzheimer's disease.
  
  
  METHODS
  The aggregation kinetics of β-peptide in presence and absence of α(s1)-casein was followed under shear at 37°C by recording the Thioflavine fluorescence, usually taken as an indicator of fibers formation. Measurements of Static and Dynamic Light Scattering, Circular Dichroism, and AFM imaging were done to reveal the details of α(s1)-casein-Aβ(1-40) interaction.
  
  
  CONCLUSIONS
  α(s1)-Casein addition sizably increases the lag-time of the nucleation phase and slows down the entire fibrillization process. α(s1)-Casein sequesters the amyloid peptide on its surface thus exerting a chaperone-like activity by means a colloidal inhibition mechanism.
  
  
  CONCLUSIONS
  Insights on the working mechanism of natural chaperones in preventing or controlling the amyloid aggregation.
authors.affiliation: Inst. of Biophysics, National Research Council, Via U. La Malfa 153, I-90146, Palermo, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Carrotta
authors.forename: C
authors.initials: C
authors.lastname: Canale
authors.forename: A
authors.initials: A
authors.lastname: Diaspro
authors.forename: A
authors.initials: A
authors.lastname: Trapani
authors.forename: P L San
authors.initials: PL
authors.lastname: Biagio
authors.forename: D
authors.initials: D
authors.lastname: Bulone
mesh_terms: D000682:Amyloid / Q000187:drug effects*; D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000378:metabolism; D052160:Benzothiazoles; D002364:Caseins / Q000494:pharmacology*; D002942:Circular Dichroism; D057446:Hydrodynamics; D008027:Light; D018625:Microscopy, Atomic Force; D010316:Particle Size; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000378:metabolism; D020836:Protein Structure, Quaternary; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D013844:Thiazoles / Q000378:metabolism; D013997:Time Factors
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D002364:Caseins; D010446:Peptide Fragments; D013844:Thiazoles; C078592:amyloid beta-protein (1-40); C009462:thioflavin T