. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 188 R. B. LOFTFIELD, E. A. EIGNER AND J. NOBEL LJ 5 > N 2 LJ c "I V CO UJ V .6 .5 .4 .3 .2 0 YEAST VALINE ENZYME TO AD FISH tRNA K = I0~6. 0 4 x 10' FIGURE 3. Eadie plot of formation of ["C]-valyl tRNA by the yeast valine enzyme. The graph shows that yeast tRNA (O) has a Km of 2 X 10~7 M and a Vmax of /t enzyme. Toadfish tRNA (X) has a Km of X 10"6 but a Vmax of M^*!., four times greater than the Vmax of yeast tRNA with yeast enzyme. Conditions as in Figure 1, except yeast tRN
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 188 R. B. LOFTFIELD, E. A. EIGNER AND J. NOBEL LJ 5 > N 2 LJ c "I V CO UJ V .6 .5 .4 .3 .2 0 YEAST VALINE ENZYME TO AD FISH tRNA K = I0~6. 0 4 x 10' FIGURE 3. Eadie plot of formation of ["C]-valyl tRNA by the yeast valine enzyme. The graph shows that yeast tRNA (O) has a Km of 2 X 10~7 M and a Vmax of /t enzyme. Toadfish tRNA (X) has a Km of X 10"6 but a Vmax of M^*!., four times greater than the Vmax of yeast tRNA with yeast enzyme. Conditions as in Figure 1, except yeast tRNA varied from to and toadfish tRNA varied from to Table I had been made with tRXA concentrations of 5 ing. per ml., the toadfish tRNA would have appeared to he three or four times more active than yeast tRNA. DISCUSSION It has been noted by ourselves and others that there is inter-species interaction of tRNA and the corresponding ligase. It has previously been thought that most non-bacterial tRNA's would interact with other non-bacterial enzymes while bac- terial tRNA would not react with non-bacterial enzymes. We (Loftfield and Eigner, 1963 ) have previously shown some cross reaction between E. coli tRNA or activating enzymes and the tRNA or enzymes derived from yeast and ascites tumors even when the rates of aminoacylation were extremely low. The present observations extend the generalization to enzymes and tRNA's from four widely differing sources. As noted previously, the failure to observe interaction as mea- sured by an immeasurably low reaction rate does not mean that there is no inter- action. Binding of the heterologous tRNA to enzyme may occur, but may be in. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Bi
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
