scholarly journals Bis(μ-oxo) Dicopper(III) Species of the Simplest Peralkylated Diamine: Enhanced Reactivity toward Exogenous Substrates

2010 ◽  
Vol 49 (23) ◽  
pp. 11030-11038 ◽  
Author(s):  
Peng Kang ◽  
Elena Bobyr ◽  
John Dustman ◽  
Keith O. Hodgson ◽  
Britt Hedman ◽  
...  
Keyword(s):  
Exogenous Substrates

Initial Polymerization Sites Indicated During Mitochondrial Oxidation of Diaminobenzidine after Toluene Treatment

1977 ◽  
Vol 35 ◽  
pp. 408-409
Author(s):  
W. A. Shannon ◽  
M. A. Matlib
Keyword(s):  
Membrane Permeability ◽  
Cytochrome Oxidase ◽  
Rat Liver ◽  
Precise Definition ◽  
Cytochemical Localization ◽  
Oxidative Reaction ◽  
Mitochondrial Oxidation ◽  
Definition Of ◽  
Exogenous Substrates

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.

Treatment of type 2 diabetic db/db mice with a novel PPARγ agonist improves cardiac metabolism but not contractile function

2004 ◽  
Vol 286 (3) ◽  
pp. E449-E455 ◽  
Author(s):  
Andrew N. Carley ◽  
Lisa M. Semeniuk ◽  
Yakhin Shimoni ◽  
Ellen Aasum ◽  
Terje S. Larsen ◽  
...  
Keyword(s):  
Contractile Function ◽  
Ex Vivo ◽  
Metabolic Changes ◽  
Pparγ Agonist ◽  
Perfused Hearts ◽  
Type 2 Diabetic ◽  
Contractile Performance ◽  
Exogenous Substrates

Hearts from insulin-resistant type 2 diabetic db/db mice exhibit features of a diabetic cardiomyopathy with altered metabolism of exogenous substrates and reduced contractile performance. Therefore, the effect of chronic oral administration of 2-(2-(4-phenoxy-2-propylphenoxy)ethyl)indole-5-acetic acid (COOH), a novel ligand for peroxisome proliferator-activated receptor-γ that produces insulin sensitization, to db/db mice (30 mg/kg for 6 wk) on cardiac function was assessed. COOH treatment reduced blood glucose from 27 mM in untreated db/db mice to a normal level of 10 mM. Insulin-stimulated glucose uptake was enhanced in cardiomyocytes from COOH-treated db/db hearts. Working perfused hearts from COOH-treated db/db mice demonstrated metabolic changes with enhanced glucose oxidation and decreased palmitate oxidation. However, COOH treatment did not improve contractile performance assessed with ex vivo perfused hearts and in vivo by echocardiography. The reduced outward K+ currents in diabetic cardiomyocytes were still attenuated after COOH. Metabolic changes in COOH-treated db/db hearts are most likely indirect, secondary to changes in supply of exogenous substrates in vivo and insulin sensitization.

Dependency of Microdissected Nephron Segments upon Oxidative Phosphorylation and Exogenous Substrates: A Relationship between Tubular Anatomical Location in the Kidney and Metabolic Activity

1989 ◽  
Vol 77 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Shozo Torikai
Keyword(s):  
Collecting Duct ◽  
Anatomical Location ◽  
Thick Ascending Limb ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Nephron Segments ◽  
Henle's Loop ◽  
Renal Tubular ◽  
Substrate Deprivation ◽  
Exogenous Substrates

1. In order to examine the possibility of heterogeneity in the dependence of renal tubular cells upon oxidative phosphorylation and exogenous substrates, the effects of antimycin A and substrate deprivation on adenosine 5′-triphosphate (ATP) content were examined in isolated rat nephron segments in vitro at 37°C. 2. Antimycin A (5 μmol/l) caused varying decrements in cell ATP level within 5 min in the following order: proximal tubules > cortical thick ascending limb of Henle's loop (cTAL) > cortical collecting duct (cCD) in the cortex, and thin descending limb of Henle's loop (TDL) > medullary thick ascending limb of Henle's loop (mTAL) > outer medullary collecting duct (omCD) in the inner stripe of the outer medulla. In the thick ascending limb and the collecting duct, the segments located in the cortex were more sensitive than those in the medulla. 3. Substrate deprivation for 30 min markedly decreased the cell ATP content in cortical and medullary proximal tubules and also in medullary TDL, whereas it caused only a slight decrease in cTAL and mTAL with no change in cCD and omCD. 4. Media made hypertonic by the addition of 200 mmol/l NaCl under aerobic conditions, increased the requirement for exogenous substrates in TDL and mTAL, but not in omCD. This stimulation was seen to a lesser extent in media made hypertonic by the addition of mannitol instead of NaCl. 5. Taking into consideration a knowledge of rat kidney architecture and intrarenal gradient of oxygen partial pressure, it is likely that the observed dependency upon both oxygen and exogenous substrates in the renal tubular cells reflects adaptation of such cells to their anatomical location, and to the availability of those substances in situ. Furthermore, extracellular sodium concentration and osmolarity stimulate metabolic requirements to a different extent among the nephron segments.

Uptake of exogenous substrates during hypoxia in fetal lambs

1988 ◽  
Vol 254 (5) ◽  
pp. E572-E578 ◽  
Author(s):  
J. R. Milley
Keyword(s):  
Umbilical Vein ◽  
Amino Nitrogen ◽  
Metabolic Substrates ◽  
Umbilical Blood ◽  
Accretion Rates ◽  
Normal Mean ◽  
Microsphere Method ◽  
Near Term ◽  
Normal Nitrogen ◽  
Exogenous Substrates

Fetal uptakes of oxygen, glucose, lactate, and alpha-amino-nitrogen containing substrates were measured in eight near-term fetal lambs by simultaneously drawing blood samples from the umbilical vein and descending aorta, then measuring umbilical blood flow using the microsphere method. These procedures were repeated after 3 h of hypoxia induced by lowering maternal inspired oxygen concentration. On the next day the experiment was repeated, except the ewes were first made hypoxic then allowed to breathe room air. These conditions decreased the delivery of oxygen, but not the delivery of other metabolic substrates to the fetus. During hypoxia, fetal oxygen uptake was 82% of normal (mean of both days); fetal glucose and amino-nitrogen uptakes were 74 and 23% of normal, respectively, and fetal lactate uptake became insignificant. These data indicate that endogenous rather than exogenous substrates are used to support fetal oxidative metabolism during hypoxia. Also, because exogenous uptake of amino-nitrogen is less than normal nitrogen accretion rates, fetal growth must be reduced as a consequence of 3-4 h of hypoxia.

scholarly journals SDS/PAGE characteristics of protein kinases tightly associated with chick embryo brain ribosomes.

1999 ◽  
Vol 46 (4) ◽  
pp. 911-917
Author(s):  
M Sanecka-Obacz
Keyword(s):  
Chick Embryo ◽  
Protein Kinases ◽  
Embryo Development ◽  
Sds Page ◽  
Casein Kinases ◽  
Triton X ◽  
Brain Ribosomes ◽  
Embryo Brain ◽  
Exogenous Substrates

Protein kinases tightly associated with chick embryo brain ribosomes washed with Triton X-100 and KCl were characterized by their ability to phosphorylate ribosomes and two exogenous substrates, histone IIA and casein. c-AMP-dependent kinase (PKA) and casein kinases (CK1, CK2) were examined in the presence of specific modulators by SDS/PAGE followed by renaturation in gel assay according to Kameshita & Fujisawa (Anal. Biochem. 1989, 183, 139-143). Basing on these data it can be presumed that PKA activity increases, but the levels of CK2 and CK1 decrease during chick embryo development.

Methanogenic responses to exogenous substrates in anaerobic rice soils

2000 ◽  
Vol 32 (11-12) ◽  
pp. 1683-1690 ◽  
Author(s):  
Y Lu ◽  
R Wassmann ◽  
H.U Neue ◽  
C Huang ◽  
C.S Bueno
Keyword(s):  
Rice Soils ◽  
Exogenous Substrates

scholarly journals Relationship between Autophosphorylation and Phosphorylation of Exogenous Substrates by the Human Cytomegalovirus UL97 Protein Kinase

2002 ◽  
Vol 76 (23) ◽  
pp. 11943-11952 ◽  
Author(s):  
Moon-Chang Baek ◽  
Paula M. Krosky ◽  
Donald M. Coen
Keyword(s):  
Protein Kinase ◽  
Fusion Protein ◽  
Human Cytomegalovirus ◽  
Time Course ◽  
Insect Cells ◽  
Nucleoside Analogs ◽  
Phosphatase Treatment ◽  
Exogenous Substrate ◽  
The Relationship ◽  
Exogenous Substrates

ABSTRACT Human cytomegalovirus encodes an unusual protein kinase, UL97, which is a member of the HvUL family of protein kinases encoded by diverse herpesviruses. UL97 is able to autophosphorylate and to phosphorylate certain exogenous substrates, including nucleoside analogs such as ganciclovir. It has previously been concluded that phosphorylation of UL97 is essential for its phosphorylation of ganciclovir. We examined the relationship between autophosphorylation of UL97 and its activity on exogenous substrates. Glutathione S-transferase-UL97 fusion protein purified from insect cells was found to be already partially phosphorylated, but neither extensive autophosphorylation nor phosphatase treatment meaningfully altered the time course of its phosphorylation of the exogenous substrate, histone H2B. Sequencing and mass spectrometric analyses of 32P-labeled tryptic peptides of the UL97 fusion protein identified nine sites of autophosphorylation, all within the first 200 residues of the protein, outside of conserved protein kinase subdomains. A peptide corresponding to the N-terminal UL97 segment that was most extensively autophosphorylated was readily phosphorylated by UL97, confirming that fusion protein sequences are not required for phosphorylation at this site. Deletion mutants lacking at least the first 239 residues exhibited drastically reduced autophosphorylation (<5%) but retained near-wild-type H2B phosphorylation activity. Baculoviruses expressing these mutants efficiently directed the phosphorylation of ganciclovir in insect cells. Taken together, these results identify the autophosphorylation sites of a herpesvirus protein kinase and show that autophosphorylation of UL97 is not required for phosphorylation of exogenous substrates.

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