DIFFERENTIAL SCANNING CALORIMETRIC STUDIES ON BOVINE SERUM-ALBUMIN .1. EFFECTS OF PH AND IONIC-STRENGTH
DIFFERENTIAL SCANNING CALORIMETRIC STUDIES ON BOVINE SERUM-ALBUMIN .1. EFFECTS OF PH AND IONIC-STRENGTH
复制标题
DOI：
10.1016/0141-8130(90)90007-w
复制
发表时间：
1990-08-01
影响因子：
8.2
通讯作者：
AOKI, K
中科院分区：
文献类型：
--
作者：
YAMASAKI, M;YANO, H;AOKI, K
用脱脂和SH封闭的牛血清白蛋白（BSA），差示扫描量热法（d.s.c.）在pH 3-11和离子强度0.001-1 M的范围内进行。D.S.C.的形状曲线分为四种状态：（i）没有峰的曲线，（ii）有峰的曲线，（iii）有肩峰的曲线，和（iv）有两个峰的曲线。用“热诱导转变”的概念解释了双峰的存在。BSA分子由两个结构域组成，由于在特定的pH和离子强度范围内BSA中形成裂缝而在化学上独立;这在d.s. c中产生两个峰。曲线由d.s.c.绘制了相对于pH和相对于NaCl浓度的曲线。在pH 5.6-9.0范围内，Δ H值随离子强度的增加而增加。在pH 4.5-9.0范围内，热变性温度（峰最大值的温度，Td）随离子强度的增加而升高，但在pH 3.5-4.0范围内降低。BSA在中性-碱性pH范围内通过NaCl的存在而稳定，但在酸性pH范围内不稳定。
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.