EFFECT OF PREGNANCY ON CYTOPLASMIC AND MITOCHONDRIAL ENZYMES IN HUMAN AND ANIMAL MYOMETRIUM

1974 ◽  
Vol 77 (2) ◽  
pp. 368-379 ◽  
Author(s):  
Helmut Geyer ◽  
Michael Riebschläger
Keyword(s):  
Lactate Dehydrogenase ◽  
Enzymatic Activity ◽  
Malate Dehydrogenase ◽  
Human Tissue ◽  
Human Myometrium ◽  
Mitochondrial Enzymes ◽  
Cellular Compartment ◽  
Cellular Localisation ◽  
Specific Activities ◽  
Mitochondrial Malate Dehydrogenase

ABSTRACT An investigation was made on the influence of pregnancy on the specific activities of cytoplasmic (lactate dehydrogenase2), cytoplasmic malate dehydrogenase) and mitochondrial enzymes (glutamate dehydrogenase, mitochondrial malate dehydrogenase, cytochrome-c-oxidase) in the human and animal myometrium. The activities were related to DNA. The specific activities of all the investigated enzymes increased. This rise in activity depended on the cellular localisation of the enzyme. The activity of all enzymes in one cellular compartment changed to the same extent. This change varied according to species. With regard to the human tissue, the increase of the cytoplasmic enzymes was larger than that of the mitochondrial enzymes. In the rat, however, a significantly larger increase of the mitochondrial enzymes was found. The increase in the specific activities of the cytoplasmic enzymes in the human and rat was proportional to the protein-content and to the hypertrophy of the cells. It was concluded that the number of mitochondria or their enzymatic activity increased in both species during pregnancy – in each species, however, to a different extent. The pattern of the LDH-isoenzymes in the myometrium changed in the same manner in the human myometrium as in the rat. The percentage of M subunits of LDH compared to H subunits rose in both cases during pregnancy.

scholarly journals MALATE DEHYDROGENASE ISOZYMES OF THE CHICK EMBRYO

1965 ◽  
Vol 13 (6) ◽  
pp. 510-514 ◽  
Author(s):  
JAMES L. CONKLIN ◽  
EDWARD J. NEBEL
Keyword(s):  
Lactate Dehydrogenase ◽  
Chick Embryo ◽  
Malate Dehydrogenase ◽  
Molecular Basis ◽  
Specific Pattern ◽  
Starch Gel Electrophoresis ◽  
Organ Specific ◽  
Malate Dehydrogenase Isozymes ◽  
Starch Gel ◽  
Mitochondrial Malate Dehydrogenase

Malate dehydrogenase fractions of the chick embryo were demonstrated after starch gel electrophoresis of homogenates of liver, brain and spleen. A total of seven malate dehydrogenase fractions were observed to occur in the chick embryo in an organ specific pattern. Treatment of the homogenates with urea, sodium chloride-sodium phosphate, and p-chloromercuribenzoate prior to electrophoresis revealed that only three distinct malate dehydrogenase-active proteins were presence. Two of these proteins exhibited properties similar to those previously reported for the supernatant malate dehydrogenase and mitochondrial malate dehydrogenase of other species. Becuase of the differing properties of chick malate and lactate dehydrogenase it is concluded that the molecular basis for malate dehydrogenase isozymes is different from that reported for lactate dehydrogenase isozymes.

Kinetics of Thyroid Hormone Induced Changes in Liver and Skeletal Muscle Enzymes of Clarias batrachus

1999 ◽  
Vol 54 (5-6) ◽  
pp. 458-462 ◽  
Author(s):  
G. Tripathi
Keyword(s):  
Skeletal Muscle ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Metabolic Enzymes ◽  
Time Dependent ◽  
Clarias Batrachus ◽  
Muscle Enzymes ◽  
Induced Changes ◽  
Kinetics Of ◽  
Mitochondrial Malate Dehydrogenase

Abstract Kinetics of triiodothyronine (T3) induced changes were studied in cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH) and lactate dehydrogenase (LDH) of the liver and skeletal muscle of a catfish, Clarias batrachus. The rates of gradual inductions in the activities of all the three metabolic enzymes were faster in skeletal muscle than those of the liver. These time-dependent and tissue-specific inductions may be due to the possible differences in the rates of different enzymic syntheses. The maximum inductions in the activities of cMDH, mMDH and LDH were recorded around 19 hr after T3 treatment. Thereafter, the activities of all the enzymes gradually declined to their half levels within the next 12 hr which reflected the physiological half-life of these metabolic enzymes in the freshwater catfish.

Gemeinsame Präparation von drei Dehydrogenasen und zwei Kinasen in einem Arbeitsgang aus Schweineherz / The Preparation of Three Dehydrogenases and Two Kinases from Pig Heart by a Single Procedure

1977 ◽  
Vol 32 (3-4) ◽  
pp. 210-218 ◽  
Author(s):  
A. Geller ◽  
J. Berghäuser
Keyword(s):  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Malate Dehydrogenase ◽  
Adenylate Kinase ◽  
Molecular Properties ◽  
Single Procedure ◽  
Specific Activities

Abstract A single procedure for the preparation of lactate dehydrogenase (EC 1.1.1.27), the mitochondrial and cytoplasmic forms of malate dehydrogenase (EC 1.1.1.37), adenylate kinase (EC 2.7.4.3) and pyruvate kinase (EC 2.7.1.40) from pig heart is described. The five enzymes are obtained in preparative amounts in homogenous form with specific activities equal to or higher than those pre­ viously reported. Some molecular properties of pig heart pyruvate kinase are determined.

scholarly journals Glucose-induced inactivation of mitochondrial enzymes in the yeast Saccharomyces cerevisiae

1981 ◽  
Vol 198 (2) ◽  
pp. 281-287 ◽  
Author(s):  
M Takeda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Malate Dehydrogenase ◽  
Mitochondrial Enzymes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cytoplasmic Proteins ◽  
Fructose 1,6 Bisphosphatase ◽  
Specific Activities

1. Addition of glucose induced an inactivation of mitochondrial enzymes in the yeast Saccharomyces cerevisiae containing normal mitochondrial particles. 2. The glucose-induced inactivation of mitochondrial enzymes was inhibited by the presence of cycloheximide. 3. Pepstatin also inhibited the inactivation, but phenylmethanesulphonyl fluoride accelerated the inactivation. 4. The specific activities of fructose 1,6-bisphosphatase and cytoplasmic malate dehydrogenase were decreased on the exposure to glucose, as well as those of the mitochondrial enzymes. However, the glucose-induced inactivation of cytoplasmic enzymes was not inhibited by the presence of pepstatin. 5. The specific activities of hexokinase and phosphofructokinase, which are cytoplasmic enzymes were increased by the addition of glucose, and this effect was not affected by pepstatin. 6. Addition of glucose resulted in an increase in the synthesis of proteins of the mitochondria and the cytosol, and simultaneously in degradation of these mitochondrial and cytoplasmic proteins.

Malate dehydrogenase: Isolation from E. coli and comparison with the eukaryotic mitochondrial and cytoplasmic forms

1981 ◽  
Vol 1 (6) ◽  
pp. 497-507 ◽  
Author(s):  
Ross T. Fernley ◽  
Steven R. Lentz ◽  
Ralph A. Aradshaw
Keyword(s):  
Malate Dehydrogenase ◽  
Deae Cellulose ◽  
Mitochondrial Enzymes ◽  
Terminal Sequence ◽  
E Coli ◽  
Amino Terminal ◽  
Common Precursor ◽  
Polypeptide Chains ◽  
Mitochondrial Malate Dehydrogenase ◽  
Amino Terminal Sequence

Escherichia coli malate dehydrogenase has been isolated in homogeneous form by a procedure employing chromatography on DEAE-cellulose, 5′-AMP-Sepharose, and Sephacryl-200. It is composed of two identical polypeptide chains each of Mr = 32 500. Like porcine mitochondrial malate dehydrogenase, it is devoid of tryptophan, but otherwise it is not particularly more similar in composition to one of the eukaryotic isozymes than to the other. However, amino-terminal sequence analysis of the first 36 residues shows remarkable similarity of the bacterial and mitochondrial enzymes (69% identical residues) in contrast to the cytoplasmic form (27%). The two porcine heart enzymes are identical in 24t% of the positions compared. These results clearly establish that all three forms of malate dehydrogenase have evolved from a common precursor and that the prokaryotic and mitochondrial forms have retained sequences that are much closer to the ancestral one than the cytoplasmic enzyme. These findings appear to further substantiate the endosymbiotic hypothesis for the origin of the mitochondrion.

THE EFFECTS OF IONS AND FREEZE–THAWING ON SUPERNATANT AND MITOCHONDRIAL MALATE DEHYDROGENASE

1967 ◽  
Vol 45 (5) ◽  
pp. 641-650 ◽  
Author(s):  
D. J. Blonde ◽  
E. J. Kresack ◽  
G. W. Kosicki
Keyword(s):  
Enzymatic Activity ◽  
Malate Dehydrogenase ◽  
Magnesium Ion ◽  
Zinc Ions ◽  
Mitochondrial Enzyme ◽  
Freezing And Thawing ◽  
Oxalacetic Acid ◽  
Activity Loss ◽  
Mitochondrial Malate Dehydrogenase ◽  
Small Activity

The effects of various ions added to the assay system for purified mitochondrial and supernatant pig-heart malate dehydrogenase have been studied. Phosphate, arsenate, and zinc ions strongly stimulate the mitochondrial enzyme. Phosphate and arsenate ions have little effect on the supernatant enzyme whereas zinc inhibits it. The stimulation by phosphate is relieved by the addition of magnesium ion, to the assay system.The effects on enzymatic activity were studied when the supernatant and mitochondrial malate dehydrogenase were subjected to freezing and thawing in various media. Freezing and thawing of the mitochondrial enzyme in Tris or citrate buffers with or without mercaptoethanol results in small activity loss. Supernatant malate dehydrogenase displays a marked loss in activity when frozen quickly in the presence of phosphate and mercaptoethanol; if mercaptoethanol is omitted, activity loss is small. NADH, oxalacetic acid (OAA), NAD, and malate protect against activity loss in the phosphate–mercaptoethanol system. Repeated freeze–thawing of mitochondrial malate dehydrogenase in the presence of both phosphate and magnesium results in extensive losses in activity. In all cases slow freezing produces little activity loss for either enzyme.

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