scholarly journals Molecular weight and subunit size of rabbit mammary-gland fatty acid synthetase

1978 ◽  
Vol 173 (3) ◽  
pp. 929-933 ◽  
Author(s):  
I Grunnet ◽  
J Knudsen

1. The molecular weights of fatty acid synthetases isolated from lactating rabbit, rat, cow and goat mammary glands were estimated by sucrose gradient centrifugation and compared by chromatography on Sepharose 6B. 2. The values obtained for all four enzymes were in the same range (0.40 × 10(6)-0.55 × 10(6)) as that found for other mammalian and avian fatty acid synthetases. The molecular weight found for the rabbit mammary enzyme therefore differs from published values of approx. 0.9 × 10(6). 3. The molecular weights of the subunits of these four synthetases were 225000-242000. Again, the value for the rabbit mammary enzyme differs from published values.

1976 ◽  
Vol 159 (1) ◽  
pp. 181-184 ◽  
Author(s):  
N Paskin ◽  
R J Mayer

Fatty acid synthetase purified from the mammary gland of the rabbit has a mol. wt. of 968000 as determined by gel filtration. The enzyme gave one band, corresponding to a mol.wt. of approx. 35000, on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate and phenylmethanesulphonyl fluoride.


1973 ◽  
Vol 132 (1) ◽  
pp. 121-123 ◽  
Author(s):  
Christopher R. Strong ◽  
Eric M. Carey ◽  
Raymond Dils

The proportion of C8:0 and C10:0 fatty acids synthesized by the microsomal plus particle-free supernatant fraction from lactating rabbit mammary gland is enhanced at high protein concentrations. This fraction appears to contain a soluble high-molecular-weight factor that modifies the specificity of the fatty acid synthetase complex for termination of the growing acyl chain.


1981 ◽  
Vol 199 (3) ◽  
pp. 789-793 ◽  
Author(s):  
M Antoniou ◽  
R Craig ◽  
R Dils

The synthesis of fatty acid synthetase on free polyribosomes from lactating rabbit mammary gland was demonstrated by using polyribosomes run-off techniques and immunochemical identification of products with synthetase antiserum. Several reproducible and discrete immunoprecipitable polypeptides were observed which were within the molecular-weight range of the synthetase subunit (235 000--252 000), as well as several of lower molecular weight.


1977 ◽  
Vol 23 (8) ◽  
pp. 1084-1087 ◽  
Author(s):  
Stephen P. Cadden ◽  
Jeffrey A. Sands

PR4 is a lipid-containing bacteriophage which is able to replicate in Escherichia coli. The virus was labeled with either [14C]leucine and [14C]threonine or H235SO4 and then purified by several rounds of sucrose gradient centrifugation. Autoradiographs showed the virus to be composed of six major protein species with molecular weights (1) 68 000, (2) 47 500, (3) 38 500, (4) 35 000, (5) 20 700, (6) 16 500 daltons. Electropherograms showed protein No. 2 to be the major protein, comprising about 43% of the total weight of viral protein.


1971 ◽  
Vol 66 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Lubomir Valenta ◽  
Michel L. Aubert

ABSTRACT Radioiodine-labelled synthetic adrenocorticotrophic hormone (ACTH), human growth hormone (HGH), human chorionic somato-mammotrophin (HCS), and human (HTSH) and bovine (BTSH) thyroid stimulating hormones were studied by disc-electrophoresis and sucrose gradient centrifugation before and after incubation with corresponding antisera. All antisera contained 7 S antibodies. After incubation, soluble antigenantibody complexes besides a small amount of precipitate were observed in the incubation mixture, characteristic of each hormone. The complexes migrated like gamma globulins or more slowly on disc-electrophoresis. and on sucrose gradient centrifugation showed patterns dependent on the time of incubation. Light 7 or 9 S, or < 12 S complexes occurred mostly after incubation for several minutes (up to 30 min) before analysis. When incubation was prolonged to 24 h and more, these relatively light complexes disappeared or diminished in favour of heavier soluble or precipitating complexes. Reproducibly obtainable sedimentation patterns of the soluble complexes suggested some definite recombination of antigen molecules with 7 S antibodies. The complexes did not occur on incubation with other sera than an antiserum to a given hormone. They were not influenced by EDTA. Displacement of the radioactivity of the complexes into the free hormone peak was obtained by addition of a non-labelled hormone identical with the labelled one. Sucrose gradient centrifugation and disc-electrophoresis are recommended for the study of immunoreaction of diluted materials and for a separate analysis of different steps of the radioimmunoassay. Radioimmunoassay was introduced for the measurement of protein hormones by Yalow & Berson (1960). The method, described originally for insulin, was later adapted to the detection of a number of protein and polypeptide hormones. On incubation of the hormone with its antiserum, a soluble antigenantibody complex is formed, which is separated from an excess of the free hormone by various methods, e. g. chromatoelectrophoresis, precipitation with a second antibody, adsorption on a solid phase etc. (Hunter 1967). Sucrose gradient centrifugation and disc-electrophoresis were occasionally used to follow some isolated aspect of radioimmunoassay (Fitschen 1965; Monjardino et al. 1968). We are demonstrating that these methods made it possible to analyze the radioimmunoassay step by step and thus may be useful for practical purposes as well as in a study of the immunoreaction of diluted materials.


1973 ◽  
Vol 56 (3) ◽  
pp. 621-627 ◽  
Author(s):  
Richard C. Franson ◽  
Moseley Waite

A single intravenous injection of 0.1 mg of heat-killed Bacillus Calmette Guérin (BCG) in 0.1 ml of Bayol F produced an accumulation of activated alveolar macrophages (BCG induced). Cells were collected 3.5–4.0 wk after injection. Phospholipases A and three lysosomal marker enzymes (acid phosphatase, ß-glucuronidase, and lysozyme) were measured in homogenates, and the distribution of the phospholipases A and lysosomal, mitochondrial, and microsomal marker enzymes were examined after sucrose gradient centrifugation of a postnuclear (1,000 g) supernatant. Homogenates of normal and BCG-induced macrophages contained phospholipases A1 and A2 which had optimal activity at pH 4.0 in the presence of 2.0 mM ethylenediaminetetraacetate (EDTA). These activities were inhibited 50–70% by 2.0 mM CaCl2. Homogenates of BCG-induced macrophages had specific activities of ß-glucuronidase, acid phosphatase, and lysozyme, which were increased 1.5- to 3.0-fold over the controls, whether expressed as activity per mg protein or activity per 107 cells. The specific activities of the phospholipases A, on the other hand, were consistently lower than those of the control. Distribution of the phospholipases A and the lysosomal marker enzymes after sucrose gradient centrifugation suggested that the phospholipases A active at pH 4.0 in the presence of EDTA are of lysosomal origin since: (a) BCG treatment caused a selective increase in the density of particles which contained both the phospholipases A and three lysosomal marker enzymes; and (b) since the density of mitochondria and microsomes were not affected by BCG treatment. The increase in the density of lysosomes seen here may be related to previously described morphologic changes of BCG-induced alveolar macrophages.


1982 ◽  
Vol 208 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M R Grigor ◽  
A Geursen ◽  
M J Sneyd ◽  
S M Warren

1. The rate of mammary-gland lipogenesis measured in vivo from 3H2O was suppressed after decreasing the milk demand by decreasing the number of pups from ten to two or three, as well as by giving diets containing lipid [Grigor & Warren (1980) Biochem. J. 188, 61-65]. 2. The specific activities of the lipogenic enzymes fatty acid synthase, glucose 6-phosphate dehydrogenase and ‘malic’ enzyme increased between 6- and 10-fold in the mammary gland and between 2- and 3-fold in the livers during the first 10 days of lactation. The increases in specific activity coupled with the doubling of liver mass which occurred during pregnancy and lactation resulted in considerable differences in total liver activities when compared with virgin animals. 3. Although consumption of a diet containing 20% peanut oil suppressed the activities of the three lipogenic enzymes in the livers, only the ‘malic’ enzyme was affected in the mammary glands. 4. In contrast, decreased milk demand did not affect the specific activities of any of the liver enzymes, whereas it resulted in suppression of all three lipogenic enzymes of the mammary glands. There was no effect on either the cytoplasmic malate dehydrogenase or the lactate dehydrogenase of the mammary gland. 5. In all the experiments performed, the activity of the fatty acid synthase correlated with the amount of material precipitated by the rabbit antibody raised against rat fatty acid synthase.


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