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Influence of nucleotides on the secondary structure and on the thermal stability of mitochondrial F 1 visualized by infrared spectroscopy
Author(s) -
Cladera Josep,
Villaverde Joaquim,
Hartog Aloysius F.,
Padrós Esteve,
Berden Jan A.,
Rigaud Jean-Louis,
Duñach Mireia
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00865-7
Subject(s) - protein secondary structure , nucleotide , chemistry , thermal stability , infrared spectroscopy , crystallography , infrared , alpha helix , denaturation (fissile materials) , biophysics , circular dichroism , biochemistry , biology , physics , nuclear chemistry , organic chemistry , optics , gene
We have studied the secondary structure of mitochondrial F 1 using infrared spectroscopy. Our results show that in the absence of added nucleotides this complex contains similar percentages of α‐helices, β‐structures and reverse turns (30%, 28% and 31%, respectively). The influence of ADP and ATP on the different types of secondary structure was determined; when all the nucleotide‐binding sites were occupied, small but reproducible changes were observed, corresponding to a decrease in β‐structure and an increase in α‐helix and reverse turns. The effect of nucleotide binding on the thermal stability of F 1 was also studied; the thermal denaturation temperature, 55°C, was increased by 11°C and 7°C by ATP and ADP, respectively. These results indicate that nucleotide binding affects the secondary structure of F 1 , stabilizing the complex.