section 14.1
Mitochondrial Structure and Properties
249
TABLE 14-1
Distribution o f Enzymes in Mitochondrial Compartments
Outer Membrane
Intermembrane Space
Inner Membrane
Matrix
NADH cytochrome b
5
Adenylate kinase
NADH-coenzyme Q
Pyruvate dehydrogenase
reductase
(myokinase)
reductase
complex
Cytochrome b
5
Nucleoside
Succinate-coenzyme Q
a-Ketoglutarate
Monoamine oxidase
diphosphokinase
reductase
dehydrogenase complex
Kynurenine hydroxylase
Nucleoside
Coenzyme QH2_
Citrate synthase
Glycerolphosphate
monophosphokinase
cytochrome c
Aconitase
acyltransferase
Sulfite oxidase
reductase
Malate dehydrogenase
Lysophosphatidyl
Cytochrome oxidase
Isocitrate dehydrogenase
transferase
Oligomycin-sensitive
[NAD+]
Phosphatidate
ATPase
Isocitrate dehydrogenase
phosphatase
jS-Hydroxybutyrate
[NADP+]
Phospholipase A
dehydrogenase
Fumarase
Nucleoside
Pyridine nucleotide
Glutamate dehydrogenase
diphosphokinase
transhydrogenase
Pyruvate carboxylase
Fatty acid elongation
Carnitine
Aspartate aminotransferase
enzyme system
palmitoyltransferase
Ornithine
Ferrochelatase
carbamoyltransferase
(heme synthase)
Fatty acyl-CoA synthetase
Adenine nucleotide
Fatty acyl-CoQ
carrier and other
dehydrogenase
carrier proteins
Enoyl hydrase
Carbamoyl phosphate
jß-Hydroxyacyl-CoA
synthetase I
dehydrogenase
Dihydroorotate
/3-Ketoacyl-CoA thiolase
dehydrogenase
Amino acid activating
(C-side)
enzymes
Glycine cleavage
RNA polymerase
enzyme complex
DNA polymerase
8
-Aminolevulinic acid synthase
HMG-CoA synthase
HMG-CoA lyase
Acetyl-CoA acetyltransferase
jß-Ketoacid CoA-transferase
Rhodanese (detected in both inner membrane and matrix)
*Coproporphyrinogen oxidase
*Protoporphyrinogen oxidase
*The exact location is not yet known.
the ATP synthase together make up at least two thirds of all
protein within the inner mitochondrial membrane. Small
uncharged molecules (e.g., water, oxygen, carbon dioxide,
ammonia, and ethanol) can diffuse through the inner mem-
brane, but all other molecules that pass through require
specific transport systems. The mitochondrial outer and
inner membranes are vastly different in their constituents
and function:
1. The outer membrane contains two to three times more
phospholipids per unit of protein;
2. Cardiolipin is localized in the inner membrane; and
3. Cholesterol is found predominantly in the outer
membrane.
The permeability of the outer membrane to charged or
uncharged substances up to a molecular weight of
1 0 , 0 0 0
