TY  - JOUR
A1  - Liu, Man
A1  - Barth, Andreas
T1  - Mapping interactions between the Ca2+-ATPase and its substrate ATP with infrared spectroscopy
T2  - Journal of biological chemistry
N2  - Infrared spectroscopy has been used to map substrate-protein interactions: the conformational changes of the sarcoplasmic reticulum Ca(2+)-ATPase upon nucleotide binding and ATPase phosphorylation were monitored using the substrate ATP and ATP analogues (2'-deoxy-ATP, 3'-deoxy-ATP, and inosine 5'-triphosphate), which were modified at specific functional groups of the substrate. Modifications to the 2'-OH, the 3'-OH, and the amino group of adenine reduce the extent of binding-induced conformational change of the ATPase, with particularly strong effects observed for the latter two. This demonstrates the structural sensitivity of the nucleotide-ATPase complex to individual interactions between nucleotide and ATPase. All groups studied are important for binding and interactions of a given ligand group with the ATPase depend on interactions of other ligand groups. Phosphorylation of the ATPase was observed for ITP and 2'-deoxy-ATP, but not for 3'-deoxy-ATP. There is no direct link between the extent of conformational change upon nucleotide binding and the rate of phosphorylation showing that the full extent of the ATP-induced conformational change is not mandatory for phosphorylation. As observed for the nucleotide-ATPase complex, the conformation of the first phosphorylated ATPase intermediate E1PCa(2) also depends on the nucleotide, indicating that ATPase states have a less uniform conformation than previously anticipated.
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/76096
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-760960
SN  - 0021-9258
VL  - 278
IS  - 12
SP  - 10112
EP  - 10118
PB  - American Society for Biochemistry and Molecular Biology Publications
CY  - Bethesda, Md
ER  -