title: Influence of nucleotides on the secondary structure and on the thermal stability of mitochondrial F1 visualized by infrared spectroscopy.
abstract: We have studied the secondary structure of mitochondrial F1 using infrared spectroscopy. Our results show that in the absence of added nucleotides this complex contains similar percentages of alpha-helices, beta-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 beta-structure and an increase in alpha-helix and reverse turns. The effect of nucleotide binding on the thermal stability of F1 was also studied; the thermal denaturation temperature, 55 degrees C, was increased by 11 degrees C and 7 degrees C by ATP and ADP, respectively. These results indicate that nucleotide binding affects the secondary structure of F1, stabilizing the complex.
authors.affiliation: Dept. Bioquimica i Biologia Molecular, Fac. Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Cladera
authors.forename: J
authors.initials: J
authors.lastname: Villaverde
authors.forename: A F
authors.initials: AF
authors.lastname: Hartog
authors.forename: E
authors.initials: E
authors.lastname: Padrós
authors.forename: J A
authors.initials: JA
authors.lastname: Berden
authors.forename: J L
authors.initials: JL
authors.lastname: Rigaud
authors.forename: M
authors.initials: M
authors.lastname: Duñach
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D004795:Enzyme Stability; D006358:Hot Temperature; D008928:Mitochondria / Q000201:enzymology*; D009711:Nucleotides / Q000378:metabolism*; D017433:Protein Structure, Secondary; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D009711:Nucleotides; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases