. Biological structure and function; proceedings. Biochemistry; Cytology. 10 OLOV LINDBERG et al. give a maximal inhibition of about 30 and 60" q, respectively. A similar pattern of inhibition could be obtained also in the case of the dinitrophenol- induced ATPase if this reaction was measured in the presence of added Mg + + (Fig. 3). Thus, whereas added Mg + + did not alter the inhibition of the dinitrophenol-induced ATPase by desaminothyroxine, it rendered the inhibition with thyroxine less efficient and with a maximal inhibition of about only 30",,. It would seem that this effect
. Biological structure and function; proceedings. Biochemistry; Cytology. 10 OLOV LINDBERG et al. give a maximal inhibition of about 30 and 60" q, respectively. A similar pattern of inhibition could be obtained also in the case of the dinitrophenol- induced ATPase if this reaction was measured in the presence of added Mg + + (Fig. 3). Thus, whereas added Mg + + did not alter the inhibition of the dinitrophenol-induced ATPase by desaminothyroxine, it rendered the inhibition with thyroxine less efficient and with a maximal inhibition of about only 30",,. It would seem that this effect of Mg + + was not due. None Desamino thyroxine mi n Fig. 4. Time-course of inhibition of the dinitrophenol-induced ATPase reaction by desaminothyroxine. When indicated desaminothyroxine was added in a final concentration of 0-2 mM. Other experimental conditions as in Fig. i. primarily to a binding of thyroxine (in which case the protection by Mg + + should have been overcome with higher concentrations of thyroxine), but rather to an ability of Mg + + to restrict the number of active sites in the preparation accessible to thyroxine. For this reason the investigations to follow were performed with desaminothyroxine. The inhibitory effect of desaminothyroxine on the dinitrophenol- induced ATPase reaction was instantaneous, as shown in Fig. 4. Pre- incubation with desaminothyroxine prior to the addition of ATP did not influence the extent of inhibition, neither in the case of this reaction, nor in the case of the Mg + +-activated ATPase reaction catalyzed by mito- chondrial fragments (Fig. 5).. 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 IUB/IUBS International Symposium (1st : 1960 : Stockholm); International Union of Biochemistry; International Union of Biological Sciences; Goodwin, T. W. (Trevor Walworth);
Size: 1730px × 1444px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiver, booksubjectbiochemistry
