scholarly journals Cytochemical localization of glycoconjugate in mitochondria.

1976 ◽  
Vol 24 (11) ◽  
pp. 1159-1168 ◽  
Author(s):  
R T Parmley ◽  
S S Spicer ◽  
K Poon ◽  
J Wright
Keyword(s):  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Similar Distribution ◽  
Intermembrane Space ◽  
Cytochemical Localization ◽  
High Iron ◽  
Complex Carbohydrates ◽  
Peroxidase Technique ◽  
Acidic Nature ◽  
Anionic Groups

Complex carbohydrates and cations have been localized by cytochemical methods in mitochondria of mammalian leukocytes, hepatocytes and oyster gill epithelium. Glycoconjugate of acidic nature was visualized with the dialyzed iron method in or on the outer membrane and inner boundary membrane and in the outer intermembrane space but not on the membranes of cristae or in the intracristate space, or matrix. Sulfated glycoconjugate was demonstrated with the high iron diamine method in a similar distribution and in, on, or between, membranes of cristae as well. Intermittent aggregates of dialyzed iron and high iron diamine stained material were often found in the outer intermembrane space. The periphery of isolated rat liver mitochondria also stained with a Concanavalin A horseradish peroxidase technique, indicating the presence of macromolecules, presumably glycoproteins containing mannose or glucose. The distribution of antimonate reactive cation in mitochondria of leukocytes resembled that of the acidic glycoconjugate, indicating binding of cations to anionic groups of the latter. The complex carbohydrates and cations demonstrated cytochemically in mitochondria are considered in relation to previous biochemical studies.

P1, P5-Bis-(5′-adenosyl)pentaphosphate: Is this Adenylate Kinase Inhibitor Substrate for Mitochondrial Processes?

1977 ◽  
Vol 32 (9-10) ◽  
pp. 786-791 ◽  
Author(s):  
Josef Köhrle ◽  
Joachim Lüstorff ◽  
Eckhard Schlimme
Keyword(s):  
Adenylate Kinase ◽  
Kinase Inhibitor ◽  
Adenine Nucleotide ◽  
Nucleoside Diphosphate Kinase ◽  
Liver Mitochondria ◽  
Inhibitory Effect ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space ◽  
Rabbit Muscle ◽  
Inner Mitochondrial Membrane

Abstract 1. P1, P5-Bis-(5′-adenosyl)pentaphosphate (Ap5A) inhibits “soluble” adenylate kinase even when this enzyme is an integral part of the complete mitochondrion. The Ki is 10-5м , i. e. about two orders of magnitude higher than the inhibitor constants determined for the purified adenylate kinase of rabbit muscle and an enzyme preparation separated from the mitochondrial intermembrane space. The weaker inhibitory effect is due to a lower accessibility of the enzyme.2. As to be expected Ap5A which is of the “multisubstrate analogue”-type does not affect mito­ chondrial nucleoside diphosphate kinase.3. Though Ap5A owns the structural elements of both ATP and ADP it is not a substrate of the adenine nucleotide carrier, i.e. neither it is exchanged across the inner mitochondrial membrane nor specifically bound.4. Ap5A is not metabolized by rat liver mitochondria.

scholarly journals Discrimination of distinct proteinases at the four structural levels of rat liver mitochondria

1986 ◽  
Vol 233 (1) ◽  
pp. 283-286 ◽  
Author(s):  
M C Duque-Magalhães ◽  
P Régnier
Keyword(s):  
Outer Membrane ◽  
Rat Liver ◽  
Degradation Products ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space ◽  
Peptidase Activity ◽  
Inner Membrane ◽  
Mitochondrial Fractions ◽  
The Matrix

Rat liver mitochondrial fractions corresponding to four morphological structures (matrix, inner membrane, intermembrane space and outer membrane) contain proteinases that cleave casein components at different rates. Proteinases of the intermembrane space preferentially cleave kappa-casein, whereas the proteinases of the outer membrane, inner membrane and matrix fractions degrade alpha S1-casein more rapidly. Electrophoretic separation of the degradation products of alpha S1-casein and kappa-casein in polyacrylamide gels shows that different polypeptides are produced when the substrate is degraded by the matrix, by both membranes and by the intermembrane-space fraction. Some of the degradation products resulting from incubation of the caseins with the mitochondrial fractions are probably the result of digestion by contaminating lysosomal proteinase(s). The matrix has a high peptidase activity, since glucagon, a small peptide, is very rapidly degraded by this fraction. These observations strongly suggest that distinct proteinases, with different specificities, are associated respectively with the intermembrane space and with both membrane fractions.

A glycoprotein located in the intermembrane space of rat liver mitochondria

FEBS Letters ◽  
1971 ◽  
Vol 17 (1) ◽  
pp. 100-105 ◽  
Author(s):  
G.L. Sottocasa ◽  
G. Sandri ◽  
E. Panfili ◽  
B. De Bernard
Keyword(s):  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space

scholarly journals Cytochemical properties of mitochondria in the gastric parietal cell.

1979 ◽  
Vol 27 (4) ◽  
pp. 873-877 ◽  
Author(s):  
P L Sannes ◽  
T Katsuyama ◽  
S S Spicer
Keyword(s):  
Cytochrome Oxidase ◽  
Parietal Cell ◽  
Light And Electron Microscopy ◽  
Intermembrane Space ◽  
Gastric Parietal Cell ◽  
High Iron ◽  
Acidic Complex ◽  
The Matrix ◽  
Complex Carbohydrates ◽  
Gastric Parietal Cells

The matrix of some mitochondria in gastric parietal cells of rat and guinea pig evidenced affinity for the high iron diamine method which localizes sulfated complex carbohydrates selectively by light and electron microscopy. Such staining has not been observed elsewhere in the stomach. The high iron diamine reactive mitochondria about equaled in number those which were unreactive, and the two groups were indistinguishable morphologically. The distinction was not apparent either when mitochondria were stained by other cytochemical procedures including dialyzed iron for acidic complex carbohydrates, 3-3' diaminobenzidine-H2O2 at pH 6.0 for cytochrome oxidase, and Kominick's pyroantimonate osmium tetroxide for antimonate precipitable cations. The dialyzed iron method stained acid glycoconjugates in the outer intermembrane space in parietal cell mitochondria. These mitochondria stained more strongly with dialyzed iron than have any others examined heretofore with this method and comprised the only reactive mitochondria in the stomach. Parietal cell mitochondria also stained strongly for cytochrome oxidase but those of other gastric cells failed to evidence this reactivity.

scholarly journals Altered release of carnitine palmitoyltransferase activity by digitonin from liver mitochondria of rats in different physiological states

1985 ◽  
Vol 230 (2) ◽  
pp. 389-394 ◽  
Author(s):  
V A Zammit ◽  
C G Corstorphine
Keyword(s):  
Liver Mitochondria ◽  
Diabetic Rats ◽  
Carnitine Palmitoyltransferase ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space ◽  
Marker Enzyme ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Cpt I ◽  
Carnitine Palmitoyltransferase Activity

The release of carnitine palmitoyltransferase (CPT) activity from rat liver mitochondria by increasing concentrations of digitonin was studied for mitochondrial preparations from fed, 48 h-starved and diabetic animals. A bimodal release of activity was observed only for mitochondria isolated from starved and, to a lesser degree, from diabetic rats, and it appeared to result primarily from the enhanced release of approx. 40% and 60%, respectively, of the total CPT activity. This change in the pattern of release was specific to CPT among the marker enzymes studied. For all three types of mitochondria there was no substantial release of CPT concurrently with that of the marker enzyme for the soluble intermembrane space, adenylate kinase. These results illustrate that the bimodal pattern of release of CPT reported previously for mitochondria from starved rats [Bergstrom & Reitz (1980) Arch. Biochem. Biophys. 204, 71-79] is not an immutable consequence of the localization of CPT activity on either side of the mitochondrial inner membrane. Sequential loss of CPT I (i.e. the overt form) from the mitochondrial inner membrane did not affect the concentration of malonyl-CoA required to effect fractional inhibition of the CPT I that remained associated with the mitochondria. The results are discussed in relation to the possibility that altered enzyme-membrane interactions may account for some of the altered regulatory properties of CPT I in liver mitochondria of animals in different physiological states.

scholarly journals The characterization of a new enzyme from rat liver mitochondria, oligophosphoglyceroyl-ATP 3′-phosphodiesterase

1991 ◽  
Vol 274 (1) ◽  
pp. 275-279 ◽  
Author(s):  
B Patel ◽  
A Costi ◽  
D L Hardy ◽  
J Mowbray
Keyword(s):  
Rat Liver ◽  
Membrane Vesicles ◽  
Total Activity ◽  
Mitochondrial Fraction ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Glyceric Acid ◽  
Intermembrane Space ◽  
Snake Venom Phosphodiesterase

By using an assay based on the precipitation of intact 14C-labelled substrate, an activity has been located in the mitochondrial fraction of rat liver which selectively hydrolyses the 3′ ester link in the fairly recently discovered oligomeric tetraphosphate derivative of ATP and glyceric acid for which the structure 3-phospho[glyceroyl-gamma-triphospho-5′-adenosine-3′-3-phospho]n-glyceroyl- gamma-triphospho-5′-adenosine has been proposed [Hutchinson, Morris & Mowbray (1986) Biochem. J. 234, 623-627]. This enzyme activity (Mr 85,000) has been purified approx. 30-fold from washed mitochondria by (NH4)2SO4 precipitation and f.p.l.c. The apparent Km for substrate (adenosine equivalents) is around 35 microM. The recovery of total activity is about 20%, and this, allied to the relatively low Vmax. found in contrast with the rapid turnover of oligomer seen in post-ischaemic tissues, suggests that some activating factors have been lost in purification. Percoll-gradient studies confirm that the activity is mitochondrial and not lysosomal or endoplasmic-reticular. The activity is latent in intact mitochondria; it is not, however, associated with intact inner-membrane vesicles but released during their preparation, implying an intermembrane-space location. The product of the enzyme is proposed to be the monomeric unit 3-phosphoglyceroyl-gamma-triphospho-5′-adenosine, from which digestion with snake-venom phosphodiesterase releases ADP.

scholarly journals Redox activation of mitochondrial intermembrane space Cu,Zn-superoxide dismutase

2005 ◽  
Vol 387 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Pedro IÑARREA ◽  
Hadi MOINI ◽  
Daniel RETTORI ◽  
Derick HAN ◽  
Jesús MARTÍNEZ ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Outer Membrane ◽  
Alkylating Agents ◽  
Liver Mitochondria ◽  
Oxidative Modification ◽  
Mitochondrial Outer Membrane ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space ◽  
H2o2 Treatment ◽  
Mitochondrial Intermembrane Space

The localization of Cu,Zn-superoxide dismutase in the mitochondrial intermembrane space suggests a functional relationship with superoxide anion (O2•−) released into this compartment. The present study was aimed at examining the functionality of Cu,Zn-superoxide dismutase and elucidating the molecular basis for its activation in the intermembrane space. Intact rat liver mitochondria neither scavenged nor dismutated externally generated O2•−, unless the mitochondrial outer membrane was disrupted selectively by digitonin. The activation of the intermembrane space Cu,Zn-superoxide dismutase following the disruption of mitochondrial outer membrane was largely inhibited by bacitracin, an inhibitor of protein disulphide-isomerase. Thiol alkylating agents, such as N-methylmaleimide or iodoacetamide, decreased intermembrane space Cu,Zn-superoxide dismutase activation during, but not after, disruption of the outer membrane. This inhibitory effect was overcome by exposing mitochondria to low micromolar concentrations of H2O2 before disruption of the outer membrane in the presence of the alkylating agents. Moreover, H2O2 treatment alone enabled intact mitochondria to scavenge externally generated O2•−. These findings suggest that intermembrane space Cu,Zn-superoxide dismutase is inactive in intact mitochondria and that an oxidative modification of its critical thiol groups is necessary for its activation.

scholarly journals LOCALIZATION OF THE ENZYMES OF KETOGENESIS IN RAT LIVER MITOCHONDRIA

1973 ◽  
Vol 58 (2) ◽  
pp. 284-306 ◽  
Author(s):  
M. John Chapman ◽  
Leonard R. Miller ◽  
Joseph A. Ontko
Keyword(s):  
Rat Liver ◽  
Ketone Body ◽  
Ketone Bodies ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Intermembrane Space ◽  
Electron Microscopic ◽  
Inner Membrane ◽  
Body Formation ◽  
Membrane Matrix

The localization of the enzymes of ketogenesis in isolated rat liver mitochondria has been investigated. Mitochondrial subfractions were isolated after disruption of this subcellular organelle by (a) hypotonic lysis in water, which permitted the ultracentrifugal separation of the soluble and membranous compartments of the mitochondrion, or by (b) a procedure involving swelling, contraction, and ultrasonic treatment, which permitted the isolation from discontinuous sucrose gradients of subfractions rich in intermembrane space protein, outer membrane, and inner membrane-matrix particles. Two membrane subfractions were invariably present as distinct bands at the lower interface of the discontinuous gradient. The upper of these two bands was found to be a highly purified preparation of outer mitochondrial membrane. Subfractions rich in matrix and in inner membrane were isolated from inner membrane-matrix particles after hypotonic treatment. The content of the various mitochondrial compartments in all subfractions was assessed from their enzymic and electron microscopic characteristics. The ketogenic activity of each subfraction was determined by measuring its capacity to form ketone bodies from acetyl CoA. The activity of this process was markedly enhanced by dithiothreitol. These measurements of ketone body formation, together with assays of individual enzymes of the ketogenic pathway, show that thiolase, HMGCoA synthase, and HMGCoA cleavage enzyme are localized in the matrix of the inner membrane-matrix particles. The rates of ketone body formation indicate that the HMGCoA synthase is the rate-limiting enzyme of the pathway in subfractions of high matrix content. Studies with sodium chloride indicate that a large portion of the HMGCoA synthase, which remains present in membrane subfractions derived from water-treated mitochondria, is bound by ionic interaction to component(s) of the membrane.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Sign in / Sign up

Export Citation Format

Share Document