Characterizing chemical systems with on-line computers and graphics: alkaline phosphatase catalyzed reaction

Abstract

mismatch to zero may be due to unknown impurities or a mechanism other than the classical competitive type.From the 1/V0 vs. [I] replot (Figure 12), a good estimate of X; ~0.45 mmol/L can be obtained which agrees well with Xmipp at [I] = 0 (Figure 13). Note, the plot is nearly perfect. Only one line, corresponding to 0.50 mmol/L substrate, is not confluent with the other 20 lines. The above are only a few examples of how response surfaces, coupled with traditional plots and replots, can be used to gain an understanding of enzyme catalyzed reactions. CONCLUSIONSMany kinds of chemical experimentation can be greatly improved by the use of the appropriate instrumentation and computers on-line to the experimental apparatus. These systems can provide many times the quantity and quality of data obtainable by manual methods. In addition this apparatus enables the experimenter to perform experiments that are otherwise impossible or extremely difficult and time consuming. Further improvements in experimental capabilities are obtained when interactive graphics are used on-line as an aid for interpretation of the vast quantities of data that are generated by an automated system.We have described an apparatus with these attributes. The system is being used to study enzyme mechanisms, optimize analytical methods, and develop new experimental and control techniques. Data obtained from the alkaline phosphatase enzyme-catalyzed reaction was used to show the versatility and power of apparatus and evolving graphic techniques.

Graphical techniques for kinetic data analyses of alkaline phosphatase

“…If the reaction follows a System C2 mechanism, plots of Umax vs. [I] should be hyperbolic. Indeed, for [S] = 0.5, the plots are hyperbolic at lower pH values and tend to become more nearly linear at Figure 6. Multiple Dixon plots for the response surface data shown in Figure 1 (runs 1-3 of Table II).…”

“…The large expansion that accompanies fusion of many organic solids leads to breakage of glass containers; although several remedies have been proposed (4,5), breakage of cylindrical zone refining tubes still occurs. Finally, it must be pointed out that attempts to convert batch zone refiners to continuous operation have resulted in complex machinery, costly to fabricate and cumbersome to operate (6). Optimum heating is attained when the heater is immersed within the sample to be purified.…”

“…We have previously described a fully computer-controlled general-purpose apparatus that can be used to characterize and model a variety of complex chemical systems (5)(6)(7). We are currently using the on-line graphics system of this apparatus to help study enzyme-catalyzed reactions; most recently, we used initial-velocity measurements to analyze reactions assumed to be in rapid or steady-state equilibrium.…”

Determination with ion selective electrodes in the low-level, non-Nernstian response region

“…Second, it was thought that if enough unique measurements (estimates of ion concentration) could be obtained, artificial intelligence techniques could be used to select the quality results from data sets containing a high percentage of erratic results. With these two suppositions in mind, a titration cell containing three ISEs and three reference electrodes was constructed and interfaced to a PDP 11/45 computer (3,4).…”

“…Each ordered pair in this set consists of a potential and a corresponding concentration of standard. This set is written as (E¡,Ci) such that i = 1, 2.....N (4) where E¡ is the potential at point i and C¿ is the concentration at point i.…”