Differential scanning calorimetric studies on bovine serum albumin: I. Effects of pH and ionic strength.


Abstract

Using defatted and SH-blocked bovine serum albumin (BSA), the measurement of differential scanning calorimetry (d.s.c.) was performed in the range pH 3-11 and ionic strength 0.001-1 M. The shape of the d.s.c. curve was classified into four regimes: (i) the curve with no peak, (ii) that with a peak, (iii) that with a peak having a shoulder, and (iv) that with two peaks. The presence of two peaks was interpreted by the concept of 'heat-induced transition'. The BSA molecule is composed of two domains, thermodynamically independent owing to the formation of a crevice in BSA in a particular range of pH and ionic strength; this gives two peaks in the d.s.c. curve. The enthalpy (delta H) from the d.s.c. curve was plotted against pH and against the NaCl concentration. The value of delta H increased with the increase in the ionic strength in the pH range 5.6-9.0. The temperature of thermal denaturation (the temperature of the peak maximum, Td) was raised with the increase in the ionic strength in the pH range 4.5-9.0, but was lowered in the pH range 3.5-4.0. BSA was stabilized in the neutral-alkaline pH range by the presence of NaCl, but was destabilized in the acidic pH range. Study holds ProTherm entries: 11292, 11293, 11294, 11295, 11296, 11297, 11298, 11299, 11300, 11301, 11302 Extra Details: buffer concentration adjusted by NaOH thermal denaturation; bovine serum albumin;,differential scanning calorimetry

Submission Details

ID: gLBtV4Y3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:42 p.m.

Version: 1

Publication Details
Yamasaki M;Yano H;Aoki K,Int. J. Biol. Macromol. (1990) Differential scanning calorimetric studies on bovine serum albumin: I. Effects of pH and ionic strength. PMID:2096908
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