anim.TCA(redox = list(O2 = c(-95, -60)), high.T = FALSE,
nframes = 100, pHlim = c(0,10), width = 420, height = 320)
anim.plasma(width=480, height=480)
anim.carboxylase(T = 25:125, ntop = 5, lcex = 0.8, width = 420, height = 320)
system
function on unix-alikes, and using shell
on Windows platforms. When installing ImageMagick on Windows, be sure to leave the To ensure the results described below, each function here does remove any existing system definition by calling data(thermo)
.
anim.TCA
creates a series of figures showing how a logaH2O - logfO2 activity diagram for various species involved in the tricarboxylic acid (TCA) cycle changes as a function of pH. Alternatively, set redox
to list(H2=c(-20,0))
to draw a logaH2O - logaH2 diagram. The diagrams are made at 25 degrees C unless high.T
is TRUE, in which case high-temperature (100 degrees C) stability fields are overlain. The number of frames to be used for the animation (as pH increases ranges between the values specified in pHlim
) is given by nframes
.
anim.plasma
produces a series of equilibrium activity diagrams for proteins in human blood plasma, as a function of log aO2 and log aH2, at 25 degrees C. Unlike most other examples in CHNOSZ, the chemical potentials of hydrogen and oxygen in the system are represented by the activities of O2 and H2, and H2O is not used as a basis species. Therefore, the equilibrium activities of H2O vary by many orders of magnitude across these diagrams. The list of proteins is taken from Anderson and Anderson (2003); see the description for the data file AA03.csv in extdata
. The first diagram shows the equilibrium predominance fields with all 71 listed proteins in the calculation. In each subsequent diagram, the protein whose predominance field occupies the greatest area on the diagram is removed. The range of heat.colors
indicates the reported reference abundances of the proteins, with the deepest (reddest) colors corresponding to the highest abundances.
anim.carboxylase
animates equilibrium rank-activity diagrams along a combined temperature and logaH2 gradient, or makes a single plot on the default device (without conversion to animated GIF) if a single temperature
is provided. The proteins in the calculation are 24 carboxylases from a variety of organisms. There are 12 ribulose phosphate carboxylase and 12 acetyl-coenzyme A carboxylase; 6 of each type are from nominally mesophilic organisms and 6 from nominally thermophilic organisms, shown as blue and red symbols on the diagrams. The activities of hydrogen at each temperature are calculated using $\log a_{\mathrm{H_{2}}_{\left(aq\right)}}=-11+3/\left(40\times T\left(^{\circ}C\right)\right)$; this equation comes from a model of relative stabilities of proteins in a hot-spring environment (Dick and Shock, 2011).
Dick, J. M. and Shock, E. L. (2011) Calculation of the relative chemical stabilities of proteins as a function of temperature and redox chemistry in a hot spring. PLoS ONE 6, e22782.
# animate a stability diagram with a high-temperature overlay
anim.TCA(high.T=TRUE)
# using H2 instead of O2
anim.TCA(list(H2=c(-20,0)))
# using anim.carboxylase in non-animation mode
anim.carboxylase(T=100)
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