DEVELOPMENT OF BIOCALORIMETERS FOR SOLUTION AND CELL BIOCHEMICAL STUDIES

以前报道的一种全钽停流微量热计 (生物物理杂志49(1986)第87a页；第51(1987)第443a页)，现已 广泛用于研究DNA-药物的结合热 互动。分解测量的热谱产生 重建的热图的时间常数约为 三秒钟。已使用两个方案来重建 测量过的热图。Davids和David的有限元方法 Berger(J.生物化学和生物物理学方法)。6(1982)，第205-217页)需要 了解量热计的物理结构。这个 Schuette和Mudd采用的迭代方法(J.Biochem&BiPhys 方法，14(1987)页167-175)只要求脉冲 响应应已知，并以与测量相同的速率数字化 热像仪。使用这两种反卷积方法的结果将是 呈上了。微量热计能够测量结合强度。 标准偏差为3的30微焦耳的热焓 微焦耳。每个反应需要80微升的试剂。 并在200秒内完成，从而允许典型的 每天120-150次的吞吐量。它的高分辨率 该仪器能够准确测量反应热在 极度稀释试剂浓度，从而排除了需要 以校正药物和/或DNA聚集的结合热。

An all tantalum stopped-flow microcalorimeter, previously reported (Biophysical Journal 49(1986) p.87a; 51(1987) p.443a), has now been used extensively to study the binding enthalpies of DNA-drug interactions. Decomposition of the measured thermograms yields reconstructed thermograms with a time constant of approximately three seconds. Two schemes have been used to reconstruct the measured thermograms. The finite element method of Davids and Berger (J. Biochem & Biophys Methods. 6(1982) p.205-217) requires a knowledge of the physical construction of the calorimeter. The iterative method adapted by Schuette and Mudd (J. Biochem & Biophys Methods, 14 (1987) p. 167-175) requires only that the impulse response be known and digitized at the same rate as the measured thermogram. Results employing both deconvolution methods will be presented. The microcalorimeter is capable of measuring binding enthalpies of 30 microjoules with a standard deviation of 3 microjoules. A reaction requires 80 microliters of each reagent and is completed within 200 seconds thus allowing a typical throughput of 120-150 runs per day. The high resolution of this instrument has permitted accurate measurement of reaction heats at extremely dilute reagent concentrations thereby precluding the need to correct the binding enthalpies for drug and/or DNA aggregation.