Effect of Nd3+ ion on carboxylation activity of ribulose-1,5-bisphosphate carboxylase/oxygenase of spinach.
Neodymium (Nd), as a member of rare earth elements, proved to enhance the photosynthesis rate and organic substance accumulation of spinach through the increase in carboxylation activity of Rubisco. Although the oxygenase activity of spinach Rubisco was slightly changed with the Nd(3+) treatment, the specific factor of Rubisco was greatly increased. It was partially due to the promotion of Rubisco activase (R-A) activity but mainly to the formation of Rubisco-Rubisco activase super-complex, a heavier molecular mass protein (about 1200kD) comprising both Rubisco and Rubisco activase. This super-complex was found during the extraction procedure of Rubisco by the gel electrophoresis and Western-blot studies. The formation of Rubisco-R-A super-complex suggested that the secondary structure of the protein purified from the Nd(3+)-treated spinach was different from that of the control. Extended X-ray absorption fine structure study of the 'Rubisco' purified from the Nd(3+)-treated spinach revealed that Nd was bound with four oxygen atoms and two sulfur atoms of amino acid residues at the Nd-O and Nd-S bond lengths of 2.46 and 2.89A, respectively.
Liu
Chao
C
College of Life Sciences, Soochow University, Suzhou 215123, PR China.
Hong
Fa-shui
FS
Wu
Kang
K
Ma
Hong-bing
HB
Zhang
Xue-guang
XG
Hong
Cheng-jiao
CJ
Wu
Cheng
C
Gao
Feng-qing
FQ
Yang
Fan
F
Zheng
Lei
L
Wang
Xue-feng
XF
Liu
Tao
T
Xie
Ya-ning
YN
Xu
Jian-hua
JH
Li
Zhong-rui
ZR
D002412:Cations / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D009354:Neodymium / Q000737:chemistry / Q000494:pharmacology*; D012273:Ribulose-Bisphosphate Carboxylase / Q000302:isolation & purification / Q000378:metabolism*; D012274:Ribulosephosphates / Q000302:isolation & purification / Q000378:metabolism*; D013057:Spectrum Analysis; D018724:Spinacia oleracea / Q000187:drug effects* / Q000201:enzymology* / Q000254:growth & development
D002412:Cations; D012274:Ribulosephosphates; C001933:ribulose-1,5 diphosphate; D009354:Neodymium; D012273:Ribulose-Bisphosphate Carboxylase