Chaperone Activities of Bovine and Camel Beta-Caseins: Importance of Their Surface Hydrophobicity in Protection Against Alcohol Dehydrogenase Aggregation

Int J Biol Macromol. 2008 May 1;42(4):392-9. doi: 10.1016/j.ijbiomac.2008.01.008. Epub 2008 Feb 7.

Abstract

Beta-casein (beta-CN) showing properties of intrinsically unstructured proteins (IUP) displays many similarities with molecular chaperones and shows anti-aggregation activity in vitro. Chaperone activities of bovine and camel beta-CN were studied using alcohol dehydrogenase (ADH) as a substrate. To obtain an adequate relevant information about the chaperone capacities of studied caseins, three different physical parameters including chaperone constant (k(c), microM(-1)), thermal aggregation constant (k(T), degrees C(-1)) and aggregation rate constant (k(t), min(-1)) were measured. Bovine beta-CN displays greater chaperone activity than camel beta-CN. Fluorescence studies of 8-anilino-1-naphthalenesulfonic acid (ANS) binding demonstrated that bovine beta-CN is doted with larger effective hydrophobic surfaces at all studied temperatures than camel beta-CN. Greater relative hydrophobicity of bovine beta-CN than camel beta-CN may be a factor responsible for stronger interactions of bovine beta-CN with the aggregation-prone pre denatured molecular species of the substrate ADH, which resulted in greater chaperone activity of bovine beta-CN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Dehydrogenase / chemistry*
  • Amino Acid Sequence
  • Anilino Naphthalenesulfonates / chemistry
  • Animals
  • Camelus
  • Caseins / chemistry*
  • Cattle
  • Dose-Response Relationship, Drug
  • Horses
  • Liver / metabolism
  • Micelles
  • Molecular Chaperones / chemistry*
  • Molecular Sequence Data
  • Sequence Homology, Amino Acid
  • Temperature

Substances

  • 8-anilino-1-naphthalenesulfonic acid
  • Anilino Naphthalenesulfonates
  • Caseins
  • Micelles
  • Molecular Chaperones
  • Alcohol Dehydrogenase