DIFFERENTIAL STABILIZING EFFECTS OF BUFFERS ON STRUCTURAL STABILITY OF BOVINE SERUM ALBUMIN AGAINST UREA DENATURATION

BUFFER INFLUENCE on PROTEIN STABILITY

Authors

  • SAAD TAYYAB University of Malaya
  • TUAN NOR NAZIAN TUAN MAT University of Malaya
  • ADYANI AZIZAH ABD HALIM University of Malaya

DOI:

https://doi.org/10.52292/j.laar.2022.738

Keywords:

bovine serum albumin, HEPES, MOPS, protein stability, urea denaturation

Abstract

The conformational stability of bovine serum albumin (BSA) against urea denaturation was investigated in aqueous solutions both in the absence and presence of buffers. Various buffers differing in polar and nonpolar characters such as sodium phosphate, Tris-HCl, (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) HEPES and [3-(N-morpholino)propanesulfonic acid] MOPS buffers were used in this study. Urea-induced structural changes were analyzed using different probes, i.e., intrinsic fluorescence, ANS fluorescence and UV-difference spectral signal.  Presence of different buffers in the incubation medium offered different degrees of resistance to the protein against urea-induced structural changes compared to those obtained in water (in the absence of buffers). A similar trend of buffer-induced structural resistance was noticed with three different probes. The stabilizing effect of these buffers followed the order: MOPS > HEPES > sodium phosphate > Tris-HCl > water. As found in MOPS and HEPES  buffers, the highest stability of BSA can be attributed to the presence of morpholine and piperazine rings, respectively, in their structures. These groups might have produced a hydrophobic environment around the protein surface, thus stabilizing protein conformation against urea denaturation.

Author Biographies

TUAN NOR NAZIAN TUAN MAT, University of Malaya

Undergraduate (Final year) student of Biochemistry, Institute of Biological Sciences 

ADYANI AZIZAH ABD HALIM, University of Malaya

Lecturer, Department of Oral and Craniofacial Sciences, Faculty of Dentistry

Published

2022-01-01