Only one of the two interconvertible forms of mitochondrial creatine kinase binds to heart mitoplasts

Marcillat, Olivier; Goldschmidt, D.; Eichenberger, D.; Vial, Christian

doi:10.1016/0005-2728(87)90024-7

Cited by 66 publications

(51 citation statements)

References 22 publications

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“…3 Depending on medium conditions, mtCK exists as two stable convertible oligomeric forms: a dimer and an octamer. [7][8][9] Solely the octamer significantly binds to the outer face of the inner mitochondrial membrane, as well as to anionic phospholipid-containing vesicles. 7,[10][11][12][13][14][15] The mtCK level is especially high at the contact sites between the inner and the outer mitochondrial membranes.…”

Section: Introductionmentioning

confidence: 99%

Interfacial behavior of cytoplasmic and mitochondrial creatine kinase oligomeric states

et al. 2005

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Adsorption to the air/water interface of isoenzymes of creatine kinase was investigated using surface pressure-area isotherms and Brewster angle microscopy (BAM) observations. Octameric mitochondrial creatine kinase (mtCK) exhibits a significant affinity for the air/water interface. Whatever the mode of formation of the interfacial film, i.e., injection of the protein in the subphase or spreading onto the buffer surface, the final arrangement and conformation adopted by mtCK molecules lead to a similar result. In contrast, the dimeric isoenzymes mtCK and cytosolic MMCK do not induce any surface pressure variation. However, when the subphase contains 0.3M NaCl, both isoenzymes adsorb to the interface. When treated with 0.8 or 3M GdnHCl, muscle creatine kinase (MMCK) becomes surface active and occupies a greater surface than mtCK. This result contrasts with previous observations, often derived from monomeric proteins, that their surface activity is increased upon unfolding. It underlines the possible influence exerted by the protein oligomeric state on its interfacial activity. At a subphase pH of 8.8, which corresponds to the pI of octameric mtCK, the profiles of the isotherms obtained with dimeric and octameric states and the resistance to compression of the protein monolayers are significantly affected when compared to those recorded at pH 7.4. These data suggest that the octamer is more hydrophobic than the dimer and may contribute to explaining why octamers bind to the inner mitochondrial membrane while dimers do not.

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Section: Introductionmentioning

confidence: 99%

Interfacial behavior of cytoplasmic and mitochondrial creatine kinase oligomeric states

et al. 2005

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“…Changes in temperature, pH, protein, or substrate concentration can dissociate MtCK octamers into dimers, but with halflife times of days to weeks (2,4). A more potent artificial dimerization trigger is the TSAC, which induces a fast dissociation of octamer within minutes (4,20,22,33) by fixing the enzyme in a conformation that destabilizes the dimer/dimer interface. Using TSAC, we could show that rate and equilibrium constants of chicken and human sMtCK are very similar, while uMtCK has much slower rate constants (dissociation is 23-34 times slower) and an increased octamer/dimer ratio at equilibrium, especially at lower protein concentration.…”

Section: Dissociation and Reassociation Kinetics Of Mtckmentioning

confidence: 99%

“…Membrane binding of MtCK is directly related to the octamer/dimer ratio, since dimers bind only very weakly (25,33,39). An in vitro assay, using SPR spectroscopy with avidin-biotin-immobilized vesicles (25,32), allowed us to determine the rate and equilibrium constants for binding of octameric MtCK to 16% cardiolipin membranes.…”

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confidence: 99%

Octamers of Mitochondrial Creatine Kinase Isoenzymes Differ in Stability and Membrane Binding

Schlattner

Wallimann

2000

Journal of Biological Chemistry

100

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Octamer stability and membrane binding of mitochondrial creatine kinase (MtCK) are important for proper functioning of the enzyme and were suggested as targets for regulatory mechanisms. A quantitative analysis of these properties, using fluorescence spectroscopy, gel filtration, and surface plasmon resonance, revealed substantial differences between the two types of MtCK isoenzymes, sarcomeric (sMtCK) and ubiquitous (uMtCK). As compared with human and chicken sMtCK, human uMtCK showed a 23-34 times slower octamer dissociation rate, a reduced reoctamerization rate and a superior octamer stability as deduced from the octamer/ dimer ratios at thermodynamic equilibrium. Octamer stability of sMtCK increased with temperature up to 30°C, indicating a substantial contribution of hydrophobic interactions, while it decreased in the case of uMtCK, indicating the presence of additional polar dimer/dimer interactions. These conclusions are consistent with the recently solved x-ray structure of the human uMtCK (Eder, M., Fritz-Wolf, K., Kabsch, W., Wallimann, T., and Schlattner, U. (2000) Proteins 39, 216 -225). When binding to 16% cardiolipin membranes, sMtCK showed slightly faster on-rates and higher affinities than uMtCK. However, human uMtCK was able to recruit the highest number of binding sites on the vesicle surface. The observed divergence of ubiquitous and sarcomeric MtCK is discussed with respect to their molecular structures and the possible physiological implications.

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“…Therefore, the individual characteristics of the mitochondrial CK, i.e., existence of two oligomeric forms [3,[29][30][31], different properties of the subunits [32], possible substrate tunneling [3], may influence the network notably. However, the existence of mitochondrial CK will anyway increase the energetic capacity ( …”

Section: Discussionmentioning

confidence: 99%

Creatine-creatine phosphate shuttle modeled as two-compartment system at different levels of creatine kinase activity

Fedosov

1994

Biochimica et Biophysica Acta (BBA) - Protein Structure and Mol

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In order to characterize ADP-ATP and creatine-creatine phosphate (Cr-CrP) shuttles a minimal mathematical model with two compartments and cyclic turnover of matter was designed. The 'mitochondrial' compartment contained 'ATP-synthase' and 'mitochondrial ereatine kinase' (mitCK). The 'cytoplasmic' compartment consisted of 'ATPase', 'cytoplasmic creatine kinase' (cytCK) and an 'ADP-binding structure'. The exchange of metabolites between these compartments was limited. Different levels of cytCK and mitCK expression as welt as different exchange rate constants between the compartments were assigned to obtain several different modes. Every steady state obtained in the presence of low ATPase activity ('resting' conditions) was then disturbed by a steep activation of ATPase ('muscle performance') and afterwards the transition to a new steady state was followed in time. The ATP-buffering capacity of the system initially acquired by cytCK expression significantly increased after additional mitCK supplement. Nevertheless, even the complete Cr-CrP shuttle failed to maintain a high [ATP]/[ADP] ratio during long term 'muscle performance' due to the rate limiting CK-transphosphorylation in the mitochondria. The facilitated diffusion of Cr and CrP was not critical, and the model worked with the same efficiency even at equal permeabilities for nucleotides and guanidines. Under 'resting conditions' the main flux of matter went through the Cr-CrP shuttle, resulting in 'pumping' of CrP. This ensured a 40 s delay in the [ATP] decrease at 'work'. The partial systems without mitCK were not as effective, and this delay was 0-10 s. However, the ADP-ATP shuttle was of more importance at the steady state achieved under ' working' conditions.

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Only one of the two interconvertible forms of mitochondrial creatine kinase binds to heart mitoplasts

Cited by 66 publications

References 22 publications

Interfacial behavior of cytoplasmic and mitochondrial creatine kinase oligomeric states

Interfacial behavior of cytoplasmic and mitochondrial creatine kinase oligomeric states

Octamers of Mitochondrial Creatine Kinase Isoenzymes Differ in Stability and Membrane Binding

Creatine-creatine phosphate shuttle modeled as two-compartment system at different levels of creatine kinase activity

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