Comparative analysis of refolding of chemically denatured beta-lactoglobulin types A and B using the dilution additive mode

Int J Biol Macromol. 2006 Feb 28;38(1):9-17. doi: 10.1016/j.ijbiomac.2005.12.010. Epub 2006 Jan 18.

Abstract

The kinetic refolding of beta-lactoglobulin (BLG), types A and B, by beta-cyclodextrin, glucose and sorbitol has been investigated in aqueous solution using fluorescence, far UV-CD and UV-spectrophotometric techniques. A new Pd-complex has been used to denature the protein. CD and fluorescence studies indicated that when incubated with sugar, the denatured BLG is refolded into the native-like structure through the dilution additive mode resulting in a higher yield of active protein than without sugar. CD studies show that these sugars can induce a non-native alpha-helical structure in denatured BLG-A and -B, then aid in the refolding of the protein. Based on the present study, these sugars have a different effect on BLG-A than BLG-B because of their differences in protein thermal stability. BLG-A has a higher thermal stability than BLG-B due to differences in the amino acid sequences.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Circular Dichroism
  • Drug Stability
  • Glucose / pharmacology
  • In Vitro Techniques
  • Kinetics
  • Lactoglobulins / chemistry*
  • Protein Folding
  • Protein Renaturation / drug effects
  • Protein Structure, Secondary
  • Sorbitol / pharmacology
  • Spectrometry, Fluorescence
  • Thermodynamics
  • beta-Cyclodextrins / pharmacology

Substances

  • Lactoglobulins
  • beta-Cyclodextrins
  • Sorbitol
  • Glucose
  • betadex