Kasper has made major contributions to the design and construction of the electrophoresis device. This result is surprising, considering the feet that the. The molecular structures of the purines and pyrimidines discussed in this thesis are shown in Figure 1. The solutions used in the pH-stat experiments already have a relatively high acid concentration, so there may be significant error in determining the amount of acid. hydrogen ion released when the complexes are formed.
One piece of information about a complex that would be useful in elucidating its formula is its charge, or in the case of a mixture, the supercharge charge. His thesis mainly describes an electrophoretic study of these complexes with the aim of determining their charge. There are two possible methods of carrying out the above .. e.) Theoretical ce.lculs.tic:ra of the charge of a canplex from measurements of its mobility and diffusion constant, and. It was therefore hoped that by comparing the mobility of the mercury complex with the protonated worm at different pH values it would be possible to substantiate the charge of the mercury canplexes.
6 - . system) the electrophoresis data strongly indicate the.t in the pH range where FB2YVD significant amounts of both the P-Hg-OH+n and. The above series of complexes provides a very useful confirmation of the semiquantitative correlation between electrical mobility and charge.
APPARATUS
The rest of the Clt tube as well as the rest of the C1.f cell is opaque to ultraviolet light. A 300 V DC supply was applied and the current through the cell was measured with a variable-range milliammeter (Sensitive Instrument Corp.). diameter of the upper row of tubes and then into the cell.
The speed of the motor driving the cams is as critical as the position of the inlet tube in the electrophoresis cell, as it determines the speed at which the solution enters the cell. To form an electrophoresis boundary one has two sets of crt syringes with solutions of the se.me densities and compositionus ~ end l_ but. The linearity of the density gradient and the completeness of mixing were confirmed by experiments.
All the purine and pyrimidine stock solutions and also any solutions containing sucrose are kept refrigerated at all times to minimize bacterial growth. Healthy of the ccmplexes were found to decanponate in the presence of ultraviolet light.
G . A•3hydroua
CALCULATIONS AND RESULTS FOR ELECTROPHORESIS AND DIWUSION
- CHs- Hg
The curves obtained in Figure 4 are exponential, since the intensity I is given by Beer' a Law. All of the above quantities can and have been obtained from the experimental curve.ao that c cx can be easily calculated. • The distance traveled by a boundary can be measured directly by measuring the displacement at c = ~ c m side.
Since .t and 1 are measurable quantities and the :t'ran error functions of table (5) can be obtained, the diffusion constants can be calculated. The electric field E was calculated from the conductivity t:1t of the ionic components on the supporting electrolyte. Also to some extent o:t' eases the actual cell voltage drop as measured by rechecking.
MISCET..LANEOUS RESULTS
The mobility changes as a function of ti.rne.. it appears that the change in mobility for mercury Cat.'Plex L." 1. Da· the hydrolysis by mercury ion-purine systems is not acccmQE:>-aied. at large ch."lnges i.c"'l spectra one is tempted to say that for some inexplicable reason in the case of 7-methyledene. At the same time it was .. shown that its mobility is the aame whether the boundary moves into or out of the density gradient.
Considering the complexity of: the flows involved ru1d also of the solutions, the average deviation of approximately 3 percent is not unexpected. As slraacl.y mentioned in the introduction, the ch[~rge Z of' e.n ion is given by Eq. For charged species in solution, the above ht:'-S equation will be modified due to the ionic atmosphere. u0 and D0 are measu..-ed O:.'lly in the limiting ce.se of very low concentrations:i:iia."l.s. T'ne t1m influencing factors £ are a) ruH:l relaxing effect b) electrophoretic effect.
This is the resistance felt by the loa due to the restraining forces due to the unsymmetrical ionic atmosphere or solvent movement~1. F due to the dissi-illiletry of the ion atmosphere is obtained approximately (8) by multiplying the ratio of the distance ion j. The ion we are interested in will also drift in the direction opposite to its motion.
These conditions are only approximately met in the actual experiments performed. It should also be noted that the stationary boundary diffusion constants were used as the moving boundary constants were generally larger due to some convective or mechanical stirring. It should be noted that for the protonated species of charge +1 the values of Z are in the range of 1 .03-1.58.
The empirical method outlined in this section looks truly hopeful as c:ne observes that the average Z. 8 's for the canplex mercury iO.Yl systems: are all in the expected range, as again determined by the electrophoresis results and The Z's observed for prototyped systems. We therefore conclude that the results obtained so far demonstrate that the empirical approach to charge determination should not be abandoned.
CZNERAL COOCLUSIONS
APPSNDIX 1
An actual experimental check may show that the light is sufficiently moo.oehranatic, so that deviations from Beer's law are not detectable. Since the e.ypa.rent light source (c) is at f'ocus, parallel light leaving the lens enters the cooling cell at point (h) through a quartz window ha.Vi.'lg a diruooter of 5 em. The cooling cell {i) is ma.d.e fran "- 1. Mounted flush with the inner walls is the cooling coil consisting of 24 t"eet of 5/16" o. In this way, the temperature of the cl.distillate ~0 in the cooling cell can be maintained at w1 thin. The electrophoresis cell, to be described separately, is placed on the (j) 14.8 em French window (b). Parallel light obtained at. g) passes through the light path of the electrophoresis cell and leaves the cooling cell through the window (k). The object and image distance are not the same because wood is in the light path. The lens is i.a. used to keep the light falling on the same spot in the heat sensitive surface regardless of where the movable slit is located. The step resistors are 68 K, there is a load resistor of 225 K and 1n parallel with the load resistor is a .05 IJ.fd capacitor. The final photocurrent is proportional to the amount of light reaching the photocell and is measured using the y input or the x-y recorder. This provides a graph of the intensity of the light passing through the electrophoresis cell versus its position in the cell. By choosing the right light filters and phototubes and with proper adjustment to the change in focal length as a function of wavelength, the device could be used for research into systems with absorption in other regions of the ultraviolet and in the visible.e. The previously cooled solution 7 is carefully applied to the solution 6 up to the top of the center of the square. The tube L is opened and the remainder of the gradient is inserted until the boundary appears in the light pe. (curve 1 - figure 4). Hg +2 and .Ag +l ions have been used to study the complexation of nitrogen base moieties (1-6). An Rs+2 ion between the bases of the Watson-Crick structure should destroy all the bald hydrogen. A bond between N-3 of the pyrimidine and rl-1 of the purine should release only one proton, 'While a bond between the N-3 C1f pyrimidine and the amino group of the purine would give a two-proton release, but requires a large amount of distortion of the DNA 'one. As pointed out by Yamane and Davidson (4), the above can be explained by assuming reaction with the N-7 or N-3 nitrogens of the purines in alternative base pairs, followed by further reaction with the remaining N-7 or N-3 accompanied by judicious replacement of thus the hydrogen bond. It is clear that the interactions of the Hg and Ag ions with DNA are complex. For the mcthy:UJ.ercury-DNA system, it should be easy to tell whether the reocticn occurs at the 1~-3 or I~-7 nitrogen of the purines, as opposed to interaction with the nitroaeno i. ."'lvolved. Thus it is felt that experiments of the type already carried out for the IIg +f. The determination of emou.11-t ~ phosphorus (P) in various materials of biological interest is often involved, tedious and unreliable (1). deterw.i."guided by the use of neutron activation analysis. in a thermal neutron pile leads to the production of radioactive p32. the number of necessary atoo is. If the neutron activation procedure is feasible, supported by the fact that Mautner et al. In light of the mobility experiments, that have already been carried out for different HP+n, s in excess of mercury ion (2), it would be uninteresting to see how the mobilities of HgP +2n. It is therefore proposed that the mobilities of the above complexes (HgP2+2 . n) be measured using radioactive ag20' isotope to detect the concentration profile of the material in question. However, one were to use Hg ions with radioactive Hg · present as a tracer, then the electrophoresis limit can be detected by carefully removing a small portion of the solution in the cell followed by either t3 or 7 counting (208 kev f'- 279 kev 7. It is suggested that in the case of adenosine and for other purines and pyrimidine derivatives where the solubility of Hg+2. The remainder of the discussion will mainly concern adenole and adenosine as representative systems. Determination of the exact position may be possible by comparing the shifts obtained with a number of different physical purines.APPENDIX 2
