Proteinaceous complexes from mitochondrial contact sites.
A Triton X-100 extract from rat brain mitochondria was obtained using low detergent/protein ratio. From this extract a proteinaceous complex was purified; its molecular weight was as high as 880 kD. The complex contained both hexokinase and creatine kinase activity. When incorporated into phospholipid bilayer membranes, the complex formed a channel whose activity was different than the channel activity of purified porin isolated either by adsorption chromatography or by dissociation from protein complexes. A ligand of the mitochondrial benzodiazepine receptor (Ro5-4864) in submicromolar concentrations had an apparent influence on the kinetic behavior of enzymatic coupling of hexokinase and creatine kinase. It is suggested that the 880-kD complex is formed by mitochondrial contact sites. The role of the isolated protein complex in the formation of nonspecific permeability in mitochondria is discussed.
Vyssokikh
M Y
MY
Belozersky Institute Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia. zorov@energ.genebee.msu.su.
Goncharova
N Y
NY
Zhuravlyova
A V
AV
Zorova
L D
LD
Kirichenko
V V
VV
Krasnikov
B F
BF
Kuzminova
A E
AE
Melikov
K C
KC
Melik-Nubarov
N S
NS
Samsonov
A V
AV
Belousov
V V
VV
Prischepova
A E
AE
Zorov
D B
DB
D000818:Animals; D001570:Benzodiazepinones / Q000378:metabolism; D001921:Brain / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D006593:Hexokinase / Q000378:metabolism; D008564:Membrane Potentials; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism
D001570:Benzodiazepinones; D009419:Nerve Tissue Proteins; D011963:Receptors, GABA-A; C028513:4'-chlorodiazepam; D006593:Hexokinase; D003402:Creatine Kinase