scholarly journals Induction of guanine deaminase and its inhibitor in rodent liver and brain

1974 ◽  
Vol 138 (2) ◽  
pp. 143-146 ◽  
Author(s):  
A. Sitaramayya ◽  
Shahid Ali ◽  
K. Sree Kumar ◽  
P. S. Krishnan
Keyword(s):  
Inhibitory Activity ◽  
Mouse Liver ◽  
Actinomycin D ◽  
Rat Tissues ◽  
Maximum Induction ◽  
Guanine Deaminase ◽  
Mouse Tissues

1. Guanine deaminase activities in homogenates and supernatant fractions of liver and brain of rat and mouse were elevated by administration of guanine to the animals. The maximum induction in mouse tissues occurred within 24h and in rat tissues within 48h. 2. Mitochondria of rat (but not mouse) liver and brain contain an inhibitor of supernatant guanine deaminase, and this was also increased by guanine treatment. 3. Administration of ethionine, cycloheximide or actinomycin D prevented the guanine-dependent increase in deaminase activity and also the increase in mitochondrial inhibitory activity; chloramphenicol suppressed only the latter.

scholarly journals Guanine deaminase in rat liver and mouse liver and brain

1972 ◽  
Vol 128 (5) ◽  
pp. 1079-1088 ◽  
Author(s):  
K. S Kumar ◽  
A. Sitaramayya ◽  
P. S. Krishnan
Keyword(s):  
Rat Brain ◽  
Rat Liver ◽  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Mouse Liver ◽  
Deae Cellulose ◽  
The Other ◽  
Guanine Deaminase ◽  
Sigmoidal Kinetics ◽  
Km Value

1. The guanine deaminase in rat liver supernatant preparations was resolved into two fractions, A and B, on DEAE-cellulose columns. The two differed in electrophoretic mobility and in various properties. The most noteworthy distinction between A and B components was that the enzyme A activity showed a sigmoid dependence on substrate concentration whereas the enzyme B showed classical Michaelis–Menten kinetics. The Km value of enzyme A for guanine was 5.3μm and that of enzyme B 20μm. 2. The entire guanine deaminase activity of mouse liver was contained in the 15000g supernatant of iso-osmotic homogenates. 3. A reinvestigation of the behaviour of rat brain 15000g supernatant guanine deaminase isoenzymes revealed that one enzyme had sigmoidal kinetics and the other enzyme showed a hyperbolic response. 4. Of the guanine deaminase in mouse brain iso-osmotic sucrose homogenate 80% was recovered in the 15000g supernatant and the rest from the particles. The supernatant guanine deaminase was resolvable into two fractions on DEAE-cellulose columns. One enzyme showed sigmoidal kinetics whereas the other showed a hyperbolic response to increasing substrate concentration; the Km values for the reaction with guanine were respectively 5 and 66μm. 5. The particulate fractions of mouse liver and brain were devoid of any overt inhibitory activity.

scholarly journals Characterization of mouse liver α-l-fucosidase. Demonstration of unusual basic isoelectric forms of the enzyme that appear to be developmentally regulated

1985 ◽  
Vol 230 (1) ◽  
pp. 75-82 ◽  
Author(s):  
L D Laury-Kleintop ◽  
I Damjanov ◽  
J A Alhadeff
Keyword(s):  
Postnatal Development ◽  
Liver Enzyme ◽  
Human Liver ◽  
Mouse Liver ◽  
Kinetic Studies ◽  
Total Activity ◽  
Cross Reactivity ◽  
Ph Optimum ◽  
Neuraminidase Treatment ◽  
Mouse Tissues

Mouse tissues contain unusual basic isoelectric forms of α-L-fucosidase (with approximate isoelectric points of 8.3 and 9.0) in addition to the usual acidic and neutral forms previously described in tissues of other species. These unusual forms are very prominent in placenta and foetal tissues and comprise approx, 50-80% of total activity up to 11 days of postnatal development. By 15 days of postnatal development, the basic forms are diminished in amount and comprise not more than 25% of total activity. Neuraminidase treatment of adult mouse liver α-L-fucosidase led to significantly decreased amounts of acidic forms and increased amounts of the basic forms, suggesting that these forms are chemically related at least in part by sialic acid residues. Comparative kinetic studies on mouse liver, human liver and mouse placental α-L-fucosidases indicated that they have the same Km (0.05-0.06 mM) for 4-methylumbelliferyl α-L-fucopyranoside but different pH optima and thermostability properties. Mouse liver α-L-fucosidase has one pH optimum (5.5) and an acidic shoulder (centred around pH 4.0) compared with two distinct optima (4.3 and 6.8) for the human liver enzyme. Mouse placental α-L-fucosidase has a pH-activity curve comparable with that of the mouse liver enzyme except that the acidic shoulder is absent. Mouse liver α-L-fucosidase is considerably more thermolabile after preincubation at 50 degrees C than are the human liver and mouse placental enzymes, which gave similar thermodenaturation curves. Immunochemical studies indicated that mouse and human α-L-fucosidases are dissimilar antigenically but exhibit some cross-reactivity. The IgG fraction of antibody prepared in goat against human liver α-L-fucosidase was ineffective by itself in immunoprecipitating mouse liver α-L-fucosidase, but 63% and 72% of the mouse liver and placental enzymes respectively could be immunoprecipitated in the double-antibody experiments under conditions that immunoprecipitated 92% of the human liver enzyme.

Isoenzymicity in mouse liver guanine deaminase demonstrable under substrate stress

1976 ◽  
Vol 70 (2) ◽  
pp. 480-484 ◽  
Author(s):  
A. Sitaramayya ◽  
K. Sree Kumar ◽  
P.S. Krishnan
Keyword(s):  
Mouse Liver ◽  
Guanine Deaminase

scholarly journals Methylation and rearrangement of mouse intracisternal a particle genes in development, aging, and myeloma.

1983 ◽  
Vol 3 (8) ◽  
pp. 1371-1380 ◽  
Author(s):  
L L Mays-Hoopes ◽  
A Brown ◽  
R C Huang
Keyword(s):  
Mouse Liver ◽  
Adult Life ◽  
Mouse Strains ◽  
Adult Liver ◽  
Myeloma Cells ◽  
Adult Mice ◽  
Mouse Tissues ◽  
Double Digestion ◽  
Genomic Dnas ◽  
Intracisternal A Particle

Sequences of DNA that hybridize on Southern blots with cloned intracisternal A-particle (IAP) sequences have been examined in genomic DNAs of neonatal mice, livers of adult mice (3, 6, 12, 18, 24, and 26 months old), and the solid myeloma tumor MOPC-315. The isoschizomers HpaII (CCGG or mCCGG) and MspI (CCGG or CmCGG) were used to assess methylation. All the DNAs produced a major 0.5-kilobase MspI fragment that hybridizes with IAP probe. Only the myeloma DNA, and to a much lesser degree DNA from senescent mouse liver, produced this fragment in HpaII digest; the other DNAs all had IAP sequences resistant to HpaII digestion. These sequences thus become fully methylated to CmCGG early and remain so in adult life, except in the myeloma cells that are expressing the IAP genes. An increase in MspI-sensitive sites in IAP gene-containing DNA was observed in aging mice. The probe used to assess methylation, a 0.8-kilobase fragment produced by BamHI-HindIII double digestion, is common to several cloned IAP genes and is part of a region of DNA which is conserved in genomes of all mouse tissues. The probe hybridized to 1.5- and 1.4-kilobase doublet bands produced by BamHI, HindIII, and EcoRI triple digestions of neonatal DNA. These two bands were found in neonatal livers of Swiss Webster, BALB/c, and C57BL/6J mouse strains, showed less in adult liver, and were barely detectable in senescent livers from C57BL/6J mice.

Overexpression of the multidrug resistance gene mdr3 in spontaneous and chemically induced mouse hepatocellular carcinomas

1990 ◽  
Vol 10 (11) ◽  
pp. 5728-5735
Author(s):  
L D Teeter ◽  
F F Becker ◽  
F V Chisari ◽  
D J Li ◽  
M T Kuo
Keyword(s):  
Multidrug Resistance ◽  
Mouse Liver ◽  
Liver Tumors ◽  
Chemotherapeutic Agents ◽  
Envelope Gene ◽  
Animal Cells ◽  
Rnase Protection ◽  
Hepatocellular Carcinomas ◽  
Protection Method ◽  
Mouse Tissues

Overexpression of a family of plasma membrane glycoproteins, known as P-glycoproteins, is commonly associated with multidrug resistance in animal cells. In rodents, three multidrug resistance (mdr or pgp) genes have been identified, but only two can confer the multidrug resistance phenotype upon transfection into animal cells. Using the RNase protection method, we demonstrated that the levels of three mdr gene transcripts differ among mouse tissues, confirming a previous report that the expression of these genes is tissue specific (J.M. Croop, M. Raymond, D. Huber, A. DeVault, R. J. Arceci, P. Gros, and D. E. Housman, Mol. Cell. Biol. 9:1346-1350, 1989). The levels of mdr transcripts were determined for mouse liver tumors spontaneously arising in both C3H/HeN and transgenic animals containing the hepatitis B virus envelope gene and for tumors induced by two different carcinogenic regimens in C57BL/6N and B6C3-F1 mice. The mdr3 gene was overexpressed in all 22 tumors tested. Our results demonstrate that overexpression of the mdr3 gene in mouse liver tumors does not require exposure of the animals to carcinogenic agents and suggest that its overexpression is associated with a general pathway of hepatic tumor development. The overexpression of the mdr3 gene, which is the homolog of human mdr1 gene, in hepatocellular carcinomas may be responsible for the poor response of these tumors to cancer chemotherapeutic agents.

Differences in inducibility by glucocorticoids of rat liver TO and TAT.

1978 ◽  
Vol 235 (4) ◽  
pp. E374
Author(s):  
J Voigt ◽  
C E Sekeris
Keyword(s):  
Rat Liver ◽  
Actinomycin D ◽  
Male Rats ◽  
Normal Male ◽  
Physiological Conditions ◽  
Maximum Induction ◽  
Level 3 ◽  
Maximal Induction ◽  
Higher Doses ◽  
Adrenalectomized Rats

The modulation of tryptophan-oxygenase (TO) and tyrosine amino-transferase (TAT) in the rat liver after a single dose of hydrocortisone has been studied under various physiological conditions. Differences in the induction behavior of the two enzymes have been observed dependent on sex, age, amount of administered hormone, and presence or absence of the adrenals. Some of the results observed are the following: 1) TO reached its maximum induction level 3 h prior to TAT in normal male rats. This difference disappeared when adrenalectomized male rats or when female animals were tested. 2) The maximal induction values of both enzymes were 50--80% higher in adrenalectomized rats than in normal rats. This effect was independent of sex. 3) Higher doses of hydrocortisone were necessary for optimal induction of TO and TAT in normal than in adrenalectomized rats. 4) The minimum dose of hydrocortisone necessary for enzyme induction was significantly lower for TO than for TAT. 5) Actinomycin D caused a complete inhibition of the induction of TO and TAT when given simultaneously with the glucocorticoid. The inhibition was less complete the longer the interval between hormone and actinomycin D administration. The activity of TAT was suppressed to a larger extent than TO.

scholarly journals Characterization of ZO-1, a protein component of the tight junction from mouse liver and Madin-Darby canine kidney cells.

1988 ◽  
Vol 106 (4) ◽  
pp. 1141-1149 ◽  
Author(s):  
J M Anderson ◽  
B R Stevenson ◽  
L A Jesaitis ◽  
D A Goodenough ◽  
M S Mooseker
Keyword(s):  
Tight Junction ◽  
Mdck Cell ◽  
Mouse Liver ◽  
Mdck Cells ◽  
Cell Protein ◽  
Scatchard Analysis ◽  
Madin Darby Canine Kidney ◽  
Mouse Tissues ◽  
Darby Canine Kidney ◽  
Canine Kidney

ZO-1, originally identified by mAb techniques, is the first protein shown to be specifically associated with the tight junction. Here we describe and compare the physical characteristics of ZO-1 from mouse liver and the Madin-Darby canine kidney (MDCK) epithelial cell line. The ZO-1 polypeptide has an apparent size of 225 kD in mouse tissues and 210 kD in canine-derived MDCK cells as determined by SDS-PAGE/immunoblot analysis. ZO-1 from both sources is optimally solubilized from isolated plasma membranes by either 6 M urea or high pH conditions; partial solubilization occurs with 0.3 M KCl. The nonionic detergents, Triton X-100 and octyl-beta-D-glucopyranoside, do not solubilize ZO-1. These solubility properties indicate that ZO-1 is a peripherally associated membrane protein. ZO-1 was purified to electrophoretic homogeneity from [35S]methionine metabolically labeled MDCK cells by a combination of gel filtration and immunoaffinity chromatography. Purified ZO-1 has an s20,w of 5.3 and Stokes radius of 8.6 nm. These values suggest that purified ZO-1 is an asymmetric monomeric molecule. Corresponding values for mouse liver ZO-1, characterized in impure protein extracts, were 6 s20,w and 9 nm. ZO-1 was shown to be a phosphoprotein in MDCK cells metabolically labeled with [32P]orthophosphate; analysis of phosphoamino acids from purified ZO-1 revealed only phosphoserine. ZO-1 epitope number was determined by Scatchard analysis of competitive and saturable binding of two different 125I-mAbs to SDS-solubilized proteins from liver and MDCK cells immobilized on nitrocellulose. Saturation binding occurs at 26 ng mAb/mg liver and 63 ng/mg of MDCK cell protein. This is equivalent to 30,000 ZO-1 molecules per MDCK cell assuming a single epitope/ZO-1 molecule.

scholarly journals Proteins of the kidney microvillar membrane. Structural and immunochemical properties of rat endopeptidase-2 and its immunohistochemical localization in tissues of rat and mouse

1989 ◽  
Vol 264 (2) ◽  
pp. 335-346 ◽  
Author(s):  
K Barnes ◽  
J Ingram ◽  
A J Kenny
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Cross Reactivity ◽  
Immunohistochemical Localization ◽  
Mouse Kidney ◽  
Molecular Forms ◽  
Rat Tissues ◽  
Weak Staining ◽  
Mouse Tissues ◽  
Rabbit Polyclonal Antibody ◽  
Solubilized Form

The phosphoramidon-insensitive endopeptidase-2 in rat renal brush borders was investigated by immunochemical approaches with a rabbit polyclonal antibody raised to the purified enzyme released from the membrane by papain. An immunoaffinity column successfully purified the detergent-solubilized form of endopeptidase-2. This preparation had an apparent subunit Mr of 80,000, and did not show the two subunits, of Mr 80,000 and 74,000, consistently found in the papain-solubilized forms, indicating that the latter resulted from proteolysis by papain. SDS/polyacrylamide-gel electrophoresis of non-reduced samples of the enzyme revealed a band of Mr 220,000, confirming the presence of disulphide-bridged subunits. Treatment with endoglycosidases H and F generated smaller molecular forms, indicating that endopeptidase-2 contained about 30% asparagine-linked carbohydrate and that a few of these oligosaccharide chains were of the high-mannose type. Treatment with phosphatidylinositol-specific phospholipase indicated that the enzyme did not possess a glycolipid membrane anchor. A survey of rat tissues examined immunohistochemically and by immunoblotting revealed that only the kidney and intestinal tract expressed the antigen in significant amounts. Although some weak staining was seen in salivary glands and thyroid, other organs and tissues including brain and spinal cord were negative by both immunochemical techniques. In the kidney the antigen was confined to the lumen of the proximal tubule and was seen mainly in the population of juxtamedullary nephrons. In the gut, luminal staining was observed throughout its whole length, from duodenum to rectum. Excellent cross-reactivity of the antibody with Balb/c mouse tissues was observed. Immunohistochemistry of mouse kidney and gut revealed a distribution identical with that observed in the rat. Immunopurification of the detergent-solubilized mouse kidney antigen showed it to be a protein containing disulphide-linked subunits of Mr 90,000. It possessed endopeptidase-2-like activity, but was more efficient in hydrolysing azo-casein and less efficient in hydrolysing a model substrate than the rat enzyme. The close similarity between rat endopeptidase-2 and mouse meprin is further supported by these results.

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