scholarly journals Physical, immunochemical, and functional properties of Acanthamoeba profilin.

1984 ◽  
Vol 98 (1) ◽  
pp. 214-221 ◽  
Author(s):  
P C Tseng ◽  
M S Runge ◽  
J A Cooper ◽  
R C Williams ◽  
T D Pollard

Acanthamoebe profilin has a native molecular weight of 11,700 as measured by sedimentation equilibrium ultracentrifugation and an extinction coefficient at 280 nm of 1.4 X 10(4) M-1cm-1. Rabbit antibodies against Acanthamoeba profilin react only with the 11,700 Mr polypeptide among all other ameba polypeptides separated by electrophoresis. These antibodies react with a 11,700 Mr polypeptide in Physarum but not with any proteins of Dictyostelium or Naeglaria. Antibody-binding assays indicate that approximately 2% of the ameba protein is profilin and that the concentration of profilin is approximately 100 mumol/liter cells. During ion exchange chromatography of soluble extracts of Acanthamoeba on DEAE-cellulose, the immunoreactive profilin splits into two fractions: an unbound fraction previously identified by Reichstein and Korn (1979, J. Biol. Chem., 254:6174-6179) and a tightly bound fraction. Purified profilin from the two fractions is identical by all criteria tested. The tightly bound fraction is likely to be attached indirectly to the DEAE, perhaps by association with actin. By fluorescent antibody staining, profilin is distributed uniformly throughout the cytoplasmic matrix of Acanthamoeba. In 50 mM KCl, high concentrations of Acanthamoeba profilin inhibit the elongation rate of muscle actin filaments measured directly by electron microscopy, but the effect is minimal in KCl with 2 MgCl2. By using the fluorescence change of pyrene-labeled Acanthamoeba actin to assay for polymerization, we confirmed our earlier observation (Tseng, P. C.-H., and T. D. Pollard, 1982, J. Cell Biol. 94:213-218) that Acanthamoeba profilin inhibits nucleation much more strongly than elongation under physiological conditions.

1977 ◽  
Vol 161 (3) ◽  
pp. 473-485 ◽  
Author(s):  
D A Swann ◽  
S Sotman ◽  
M Dixon ◽  
C Brooks

The articular lubricating fraction from bovine synovial fluid was prepared by repeated fractionation in three consecutive CsCl density gradients to remove completely traces of hyaluronic acid. The major glycoprotein consituent (LGP-I) was then isolated by repeated gel-permeation chromatography. The yield of the LGP-I component was about 20 mg/litre of synovial fluid. Sedimentation-equilibrium measurements showed that this glycoprotein was homogeneous and the mol.wt. was calculated to be 227500. Amino acids represented 43% (w/w) and carbohydrate constituents 44% (w/w) of the molecule. Threonine, glutamic acid, proline and lysine (224, 127, 242 and 128 residues/1000 residues respectively) were the major amino acids. Galactosamine, galactose and N-acetylneuraminic acid (202, 162 and 114 residues/molecule of LGP-I component respectively) accounted for 98% of the total carbohydrate residues present. Small amounts of mannose and glucosamine (1 and 9mol respectively/mol of LGP-I component) were also present. After treatment of LGP-I component with alkali and NaB3H4 radioactivity was incorporated into alpha-aminobutyric acid and alanine in a molar ratio of 4:1, and radioactive galactosaminitol was isolated by ion-exchange chromatography from a cleaved oligosaccharide fraction. These data demonstrate the presence of threonine and serine -O-GalNAc linkages, but only 25% of the theoretical likages involving threonine were cleaved by a beta-elimination reaction. Digestion of LGP-I component with Pronase followed by chromatography on DEAE-cellulose yielded glycopeptide fractions with a similar amino acid and carbohydrate composition to the intact molecule. Treatment of desialylated and intact LGP-I component with galactose oxidase followed by reduction with NaB3H4 revealed the presence of 52mol of terminal galactose in the intact molecule and 153mol of galactose/mol of LGP-I component after treatment with neuraminidase. The data indicate the LGP-I component is composed of a single polypeptide chain containg more than 150 oligaosaccharide side chains composed of O-GaINAc-Gal distributed over the length of the peptide chain and that terminal sialic acid residues are linked to galactose in two-thirds of these side chains.


1976 ◽  
Vol 54 (9) ◽  
pp. 788-795 ◽  
Author(s):  
S. Demassieux ◽  
R. Boucher ◽  
C. Grisé ◽  
J. Genest

Tonin was purified from rat submaxillary glands by differential centrifugation, ammonium sulphate precipitation, gel filtration on Sephadex G150, and by ion-exchange chromatography on DEAE-cellulose, phospho-cellulose, SP-Sephadex C25, and SP-Sephadex C50. Purified tonin was shown to be homogeneous by analytical electrophoresis and by analytical ultracentrifugation analysis. Purified tonin was very stable when stored in buffers of low pH values or when incubated at high temperatures in neutral solutions. The molecular weight estimated by sedimentation equilibrium was 28 700. The pH optimum was near 6.8 in a 0.1 M potassium phosphate buffer. The Michaelis–Menten constant for tonin using angiotensin I as substrate was about 4 × 10−5 M. Tonin activity was strongly inhibited by plasma. Kinetic studies using angiotensin I as substrate showed that the inhibition of tonin by plasma was of the non-competitive type.


1961 ◽  
Vol 114 (1) ◽  
pp. 89-110 ◽  
Author(s):  
Gerald Goldstein ◽  
Irene S. Slizys ◽  
Merrill W. Chase

1. A study has been made of the non-specific fluorescent staining of splenic imprints treated with fluorescent sheep antibody globulins. 2. In tissue imprints made with the spleens of antigen-stimulated animals, no morphological distinction was evident between areas showing non-specific fluorescence and specific fluorescence. 3. Elimination of non-specific fluorescence was not achieved by any one, or any combination of the following: (a) conjugating only gamma globulins with fluorescein isothiocyanate; (b) removal of dialyzable fluorescent products on sephadex, followed by concentration through the use of pressure dialysis; (c) use of crystalline preparations of fluorescein isothiocyanate. 4. Individual preparations of fluorescent antibodies were separated by gradient elution chromatography on diethylaminoethyl (DEAE) cellulose into fractions possessing different numbers of fluorescein radicals per molecule of globulin. 5. The coupling ratio of 50 mg fluorescein isothiocyanate (FITC) per gm of protein, as commonly advocated, can not be recommended for the precise localization of antibody globulin in tissues owing to the capacity of the coupled products to give non-specific fluorescent staining. When crystalline preparations of FITC are used instead of the amorphous product at 50 mg/gm protein, far too high non-specific fluorescence results. 6. A fraction with bright specific fluorescence and no or negligible nonspecific fluorescence was obtained from each fluorescent antibody that was prepared by using 6 to 8 mg of crystalline fluorescein isothiocyanate per gm of globulin and was then subjected to DEAE-cellulose chromatography and gradient elution to eliminate the most highly coupled molecules.


1981 ◽  
Vol 88 (2) ◽  
pp. 346-351 ◽  
Author(s):  
I M Herman ◽  
T D Pollard

We localized myosin in vertebrate nonmuscle cells by electron microscopy using purified antibodies coupled with ferritin. Native and formaldehyde-fixed filaments of purified platelet myosin filaments each consisting of approximately 30 myosin molecules bound an equivalent number of ferritin-antimyosin conjugates. In preparations of crude platelet actomyosin, the ferritin-antimyosin bound exclusively to similar short, 10-15 nm wide filaments. In both cases, binding of the ferritin-antimyosin to the myosin filaments was blocked by preincubation with unlabeled antimyosin. With indirect fluorescent antibody staining at the light microscope level, we found that the ferritin-antimyosin and unlabeled antimyosin stained HeLa cells identically, with the antibodies concentrated in 0.5-microns spots along stress fibers. By electron microscopy, we found that the concentration of ferritin-antimyosin in the dense regions of stress fibers was five to six times that in the intervening less dense regions, 20 times that in the cytoplasmic matrix, and 100 times that in the nucleus. These concentration differences may account for the light microscope antibody staining pattern of spread interphase cells. Some, but certainly not all, of the ferritin-antimyosin was associated with 10-15-nm filaments. In mouse intestinal epithelial cells, ferritin-antimyosin was located almost exclusively in the terminal web. In isolated brush borders exposed to 5 mM MgCl2, ferritin-antimyosin was also concentrated in the terminal web associated with 10-15-nm filaments.


1979 ◽  
Vol 42 (05) ◽  
pp. 1452-1459 ◽  
Author(s):  
Robert H Yue ◽  
Toby Starr ◽  
Menard M Gertler

SummaryCommercial porcine heparin can be separated into three distinct subtractions by using DEAE-cellulose chromatography and a stepped salt gradient. Gram quantities of heparin can be fractionated by this technique. All three heparin subtractions can accelerate the inhibition of thrombin by antithrombin III with different efficiency. The specific activities of the high activity heparin, intermediate activity heparin and low activity heparin are 228 units/mg, 142 units/mg and 95 units/mg, respectively. Both the uronic acid content and the quantity of N-SO4 for all three heparin subfractions have been evaluated. The high activity heparin has the lowest uronic acid and N-SO4 content. The successful separation of commercial heparin into three distinct subfractions by means of ion-exchange chromatography suggests that the net charge on these three heparin components will serve as a model system in the elucidation of the structure and activity relationship to the biological function of heparin.


1991 ◽  
Vol 24 (2) ◽  
pp. 143-147 ◽  
Author(s):  
N. A. Grabow ◽  
R. Kfir ◽  
W. O. K. Grabow

A new quantitative method for the enumeration of Legionella bacteria in water is described. Appropriate tenfold serial dilutions of water samples concentrated by membrane filtration are plated in triplicate on buffered charcoal yeast extract agar. After incubation for 3 days representative smears from individual plates are tested for the presence of Legionella by direct fluorescent antibody staining. The number of positive plates in each dilution is used to calculate the Legionella count by means of conventional most probable number statistics. In comparative tests on a variety of water samples this method yielded significantly higher counts than previously used procedures.


1981 ◽  
Vol 193 (1) ◽  
pp. 375-378 ◽  
Author(s):  
A R Ashton ◽  
L E Anderson

Plastocyanin is soluble at high concentrations (greater than 3 M) of (NH4)2SO4 but under these conditions will adsorb tightly to unsubstituted Sepharose beads. This observation was utilized to purify plastocyanin from pea (Pisum sativum) in two chromatographic steps. Sepharose-bound plastocyanin was eluted with low-ionic-strength buffer and subsequently purified to homogeneity by DEAE-cellulose chromatography.


1980 ◽  
Vol 187 (3) ◽  
pp. 647-653 ◽  
Author(s):  
K Arakawa ◽  
M Yuki ◽  
M Ikeda

Tryptensin, a vasopressor substance generated from human plasma protein fraction IV-4 by trypsin, has been isolated and the amino acid composition analysed. The procedures used for the isolation were: (a) adsorption of the formed tryptensin on Dowex 50W (X2; NH4+ form); (b) gel filtration through Sephadex G-25; (c) cation-exchange chromatography on CM-cellulose; (d) anion-exchange chromatography on DEAE-cellulose; (e) re-chromatography on CM-cellulose; (f) gel filtration on Bio-Gel P-2; (g) partition chromatography on high-pressure liquid chromatography. The homogeneity of the isolated tryptensin was confirmed by thin-layer chromatography and thin-layer electrophoresis. The amino acid analysis of the hydrolysate suggested the following proportional composition: Asp, 1; Val, 1; Ile, 1; Tyr, 1; Phe, 1; His, 1; Arg, 1; Pro, 1. This composition is identical with that of human angiotensin.


1962 ◽  
Vol 116 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Richard A. Rifkind ◽  
Elliott F. Osserman ◽  
Konrad C. Hsu ◽  
Councilman Morgan

Ferritin- and fluorescein-conjugated antibody staining has been applied to a study of a mouse plasma cell tumor. The presence of myeloma globulin within cisternae of the endoplasmic reticulum was observed at a stage of the secretory process when the remainder of the cytoplasm was essentially free of labeled globulin. The distribution of ferritin suggested a functional heterogeneity among units of the endoplasmic reticulum. Apparently, progressive accumulation of globulin results in distension of the endoplasmic reticulum and, occasionally, in the appearance of considerable quantities of this secretory protein in the extracisternal cytoplasmic matrix. Participation of the Golgi apparatus in the packaging and release of small quantitites of globulin seems likely. In addition, however, fragmentation of the peripheral cytoplasm with rupture of distended ergastoplasmic vesicles appeared to be another pathway whereby globulin is secreted.


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