Wu J Q, Macgregor R B
Department of Medicinal Chemistry, University of Illinois, Chicago 60612.
Anal Biochem. 1993 May 15;211(1):66-71. doi: 10.1006/abio.1993.1234.
The position of an equilibrium is a function of pressure and temperature. Generally, only temperature effects are discussed for biochemical systems; however, pressure perturbations can offer interesting insights into the role of hydration in a reaction. We describe the construction and characteristics of an instrument that allows computer control of the temperature and pressure throughout the range -40 to +140 degrees C and 0.1 to 250 MPa, as well as automatic data acquisition from either a spectrophotometer or a spectrofluorimeter. To test the performance of the system the effect of pressure on the thermal denaturation of poly[d(A-T)] and poly(dA).poly(dT) has been investigated. In 20 mM NaCl, 20 mM Tris-HCl, pH 8.9, the delta V degrees for poly[d(A-T)] equals +0.30 +/- 0.09 cm3/mol (base pairs), and for poly(dA).poly(dT) delta V degrees equals +3.05 +/- 0.15 cm3/mol (base pairs). Although we focus on the use of this instrument to measure thermal denaturation curves, it can be employed to study the equilibrium of any reaction that can be followed optically in the ultraviolet or visible.
平衡的位置是压力和温度的函数。一般来说，对于生化系统，通常只讨论温度效应；然而，压力扰动可以为水合作用在反应中的作用提供有趣的见解。我们描述了一种仪器的构造和特性，该仪器能够在-40至+140摄氏度以及0.1至250兆帕的范围内对温度和压力进行计算机控制，还能从分光光度计或荧光分光光度计自动采集数据。为了测试该系统的性能，研究了压力对聚[d(A-T)]和聚(dA)·聚(dT)热变性的影响。在20 mM NaCl、20 mM Tris-HCl、pH 8.9条件下，聚[d(A-T)]的ΔV°等于+0.30±0.09 cm³/mol（碱基对），聚(dA)·聚(dT)的ΔV°等于+3.05±0.15 cm³/mol（碱基对）。尽管我们重点关注该仪器用于测量热变性曲线，但它可用于研究任何能在紫外或可见光下通过光学手段跟踪的反应的平衡。
