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PubMed · 9675202

Structural changes of creatine kinase upon substrate binding.

M Forstner·M Kriechbaum·P Laggner·T Wallimann
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Abstract

Small-angle x-ray scattering was used to investigate structural changes upon binding of individual substrates or a transition state analog complex (TSAC; Mg-ADP, creatine, and KNO3) to creatine kinase (CK) isoenzymes (dimeric muscle-type (M)-CK and octameric mitochondrial (Mi)-CK) and monomeric arginine kinase (AK). Considerable changes in the shape and the size of the molecules occurred upon binding of Mg-nucleotide or TSAC. The radius of gyration of Mi-CK was reduced from 55.6 A (free enzyme) to 48.9 A (enzyme plus Mg-ATP) and to 48.2 A (enzyme plus TSAC). M-CK showed similar changes from 28.0 A (free enzyme) to 25.6 A (enzyme plus Mg-ATP) and to 25.5 A (enzyme plus TSAC). Creatine alone did not lead to significant changes in the radii of gyration, nor did free ATP or ADP. AK also showed a change of the radius of gyration from 21.5 A (free enzyme) to 19.7 A (enzyme plus Mg-ATP), whereas with arginine alone only a minor change could be observed. The primary change in structure as seen with monomeric AK seems to be a Mg-nucleotide-induced domain movement relative to each other, whereas the effect of substrate may be of local order only. In CK, however, additional movements have to be involved.

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Adenosine TriphosphateAlgorithmsAnimalsArginine KinaseChickensCloning, MolecularComputer SimulationCreatine KinaseCrystallography, X-RayDimerizationEscherichia coliIsoenzymesMitochondriaMitochondria, MuscleProtein BindingProtein ConformationProtein Structure, SecondaryRecombinant ProteinsSarcomeresScattering, RadiationX-RaysJournal ArticleResearch Support, Non-U.S. Gov't

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M Forstner, M Kriechbaum, P Laggner, T Wallimann. 1998. Structural changes of creatine kinase upon substrate binding.. https://doi.org/10.1016/s0006-3495(98)77590-3

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