Studies on photophosphorylation utilizing methylene diphosphonate analogs of ADP and ATP |
| |
Authors: | Arnost Horak Saul Zalik |
| |
Institution: | Department of Plant Science, University of Alberta, Edmonton, Alberta Canada |
| |
Abstract: | Spinach chloroplasts were able to photophosphorylate the ADP analog α,β-methylene adenosine 5′-diphosphate (AOPCP). Phosphorylation of AOPCP was catalyzed by chloroplasts that were washed or dialyzed to remove free endogenous nucleotides. In the presence of glucose, hexokinase, AOPCP and 32Pi, the 32P label was incorporated into α,β-methylene adenosine 5′-triphosphate (AOPCPOP).In contrast to photophosphorylation of AOPCP, the ATP analog AOPCPOP was a poor substrate for the ATP-Pi exchange reaction and its hydrolysis was neither stimulated by light and dithiothreitol nor inhibited by Dio-9.Photophosphorylation of AOPCP was inhibited by the α,β- and β,γ-substituted methylene analogs of ATP, while phosphorylation of ADP was unaffected by them. The ATP-Pi exchange was also unaffected by both ATP analogs, while the weak AOPCPOP-Pi exchange was inhibited by the β,γ-methylene analog of ATP.Direct interaction of methylene analogs with the chloroplast coupling factor ATPase was indicated by the enzymatic hydrolysis of AOPCPOP on polyacrylamide gels. |
| |
Keywords: | AOPCP α β-methylene adenosine 5′-diphosphate AOPCPOP α β-methylene adenosine 5′-triphosphate AOPOPCP β γ-methylene adenosine 5′-triphosphate TES tris (hydroxymethyl) methylaminoethane sulfonic acid |
本文献已被 ScienceDirect 等数据库收录! |
|