TY  - JOUR
A1  - Liu, Man
A1  - Barth, Andreas
T1  - Phosphorylation of the sarcoplasmic reticulum Ca(2+)-ATPase from ATP and ATP analogs studied by infrared spectroscopy
T2  - Journal of biological chemistry
N2  - Phosphorylation of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1a) was studied with time-resolved Fourier transform infrared spectroscopy. ATP and ATP analogs (ITP, 2'- and 3'-dATP) were used to study the effect of the adenine ring and the ribose hydroxyl groups on ATPase phosphorylation. All modifications of ATP altered conformational changes and phosphorylation kinetics. The differences compared with ATP increased in the following order: 3'-dATP > ITP > 2'-dATP. Enzyme phosphorylation with ITP results in larger absorbance changes in the amide I region, indicating larger conformational changes of the Ca(2+)-ATPase. The respective absorbance changes obtained with 3'-dATP are significantly different from the others with different band positions and amplitudes in the amide I region, indicating different conformational changes of the protein backbone. ATPase phosphorylation with 3'-dATP is also much ( approximately 30 times) slower than with ATP. Our results indicate that modifications to functional groups of ATP (the ribose 2'- and 3'-OH and the amino group in the adenine ring) affect gamma-phosphate transfer to the phosphorylation site of the Ca(2+)-ATPase by changing the extent of conformational change and the phosphorylation rate. ADP binding to the ADP-sensitive phosphoenzyme (Ca(2)E1P) stabilizes the closed conformation of Ca(2)E1P.
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/76168
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-761681
SN  - 0021-9258
VL  - 279
IS  - 48
SP  - 49902
EP  - 49909
PB  - American Society for Biochemistry and Molecular Biology Publications
CY  - Bethesda, Md
ER  -