Conformational change of bovine serum albumin by heat treatment

Abstract

The thermal denaturation of bovine serum albumin (BSA) was studied at pH 2.8 and 7.0 in the range of 2-65 degrees C. The relative proportions of alpha-helix, beta-structure, and disordered structure in the protein conformation were determined as a function of temperature, by the curve-fitting method of circular dichroism spectra. With the rise of temperature at pH 7.0, the proportion of alpha-helix decreased above 30 degrees C and those of beta-structure and disordered structure increased in the same temperature range. The structural change was reversible in the temperature range below 45 degrees C. However, the structural change was partially reversible upon cooling to room temperature subsequent to heating at 65 degrees C. On the other hand, the structural change of BSA at pH 2.8 was completely reversible in the temperature range of 2-65 degrees C, probably because the interactions between domains and between subdomains might disappear due to the acid expansion. The secondary structure of disulfide bridges-cleaved BSA remained unchanged during the heat treatment up to 65 degrees C at pH 2.8 and 7.0.

Screening System for the Maillard Reaction Inhibitor from Natural Product Extracts.

“…However, Takeda et al reported a conformational change by heat treatment of BSA namely, the α-helical structure began to decrease and convert into a β-structure at over 40°C. 30,31) This result was a little different from our observation that there was no remarkable conformational change up to 60°C. We used Fraction V of BSA, whereas Takeda et al utilized high-pure crystallized BSA, so it seems to show different stability at high temperature.…”

Darkfield orthogonal polarized spectral imaging for studying endovascular laser-tissue interactions in vivo-a preliminary study

“…Unfortunately, DFOPS imaging at this magnification is limited insofar as the translucent material cannot be conclusively characterized and no irrefutable distinction can be made between the various translucent constituents. Despite these limitations, it is arguable that the blood-borne translucent bodies are comprised of thermally denatured and precipitated plasma proteins, which have a lower irreversible denaturation threshold than lipoproteins or cell membranes [20,26] due to the lack of thermodynamically stabilizing phospholipids [27]. Generated intraluminal isotherms may therefore be subcritical for thermolysis and agglutination (>80˚C) [24] of red blood cells, yet exceed the threshold values for irreversible plasma protein denaturation (i.e., >45˚C for serum albumin) [26].…”

Influence of Fractional Electromagnetic Radiation Doses on Biosensor Matrix Component Stability

“…Depending on external factors, the tested component of the biosensor matrix can be crushed in whole or in part only. Takeda et al [14] have discovered that secondary structural changes occur only after the reduction of disulfide bones. Then the helix content drops from 66% to 25%, the β structure content increases from 3% to 19%.…”

“…BSA conformational changes caused by varying pH or temperature were the subject of earlier research [14,15]. Reports on the effect of non-ionizing electromagnetic radiation at 200 MHz frequency applied in fractional doses to protein were not found.…”