scholarly journals Fate of surface proteins of rabbit polymorphonuclear leukocytes during phagocytosis. I. Identification of surface proteins.

1979 ◽  
Vol 82 (1) ◽  
pp. 32-44 ◽  
Author(s):  
M Willinger ◽  
F R Frankel
Keyword(s):  
Gel Electrophoresis ◽  
Polymorphonuclear Leukocytes ◽  
Wheat Germ ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Surface Proteins ◽  
Intact Cells ◽  
Dense Fraction ◽  
Protease Treatment ◽  
Neutrophil Cell

To study the fate of external membrane proteins during phagocytosis, rabbit peritoneal neutrophils were labeled by enzymatic iodination. Iodine was incorporated into at least 13 proteins ranging in size from approximately 250,000 to 18,000 daltons as judged from autoradiography of gels after SDS-polyacrylamide gel electrophoresis of labeled cells. The major contractile proteins of neutrophils, actin and myosin, were not labeled when intact cells were iodinated but were labeled when homogenates of these cells were iodinated. Nine of the iodinated proteins were released by mild protease treatment of intact cells. A plasma membrane-rich fraction was isolated by density centrifugation. This fraction was enriched at least 10-fold for lactoperoxidase-labeled acid-insoluble proteins. It was enriched to the same extent for the presence of iodinated wheat germ agglutinin that had been bound to intact cells at 4 degrees C before homogenization. Analysis of SDS-polyacrylamide gel electrophoresis revealed that the proteins of this fraction were predominantly of high molecular weight. However, only 8 of the 13 proteins iodinated on intact cells were found in this fraction. The remaining five were enriched in a dense fraction containing nuclei, intact cells, and membranous vesicles, and may represent a specialized segment of the neutrophil cell surface.

scholarly journals Cell-surface radioiodination with the sparingly soluble catalyst Iodogen. Difference between the dividing and non-dividing populations of rodent thymocytes

1981 ◽  
Vol 194 (1) ◽  
pp. 351-355 ◽  
Author(s):  
J G Salisbury ◽  
J M Graham
Keyword(s):  
Cell Surface ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Surface Proteins ◽  
New Method

The surface proteins of dividing and non-dividing subpopulations of rat and mouse thymocytes have been labelled by using a new method of radioiodination. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and autoradiography of the labelled proteins shows distinct differences in labelling between the mouse and rat cells and also, in the case of the rat, between the dividing and non-dividing populations.

scholarly journals A set of surface proteins common to the circulating human platelet and lymphocyte

1974 ◽  
Vol 141 (3) ◽  
pp. 909-911 ◽  
Author(s):  
M. J. A. Tanner ◽  
D. H. Boxer ◽  
Jane Cumming ◽  
J. Verrier-Jones
Keyword(s):  
Gel Electrophoresis ◽  
Human Platelet ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Surface Proteins ◽  
Major Type ◽  
Cell Type ◽  
Peptide Maps

The surface proteins of the circulating human platelet and lymphocyte were labelled by using the lactoperoxidase iodination method. Polyacrylamide-gel electrophoresis showed that four corresponding labelled proteins are found on the surface of each cell type. The most intensely labelled protein contains little or no carbohydrate, but the remaining labelled proteins are all glycoproteins. The major labelled band from each cell was isolated and comparative peptide ‘maps’ showed that the two proteins are closely similar. The surface proteins of the lymphocyte and platelet are distinct from those on the erythrocyte, the remaining major type of circulating cell.

scholarly journals Chemical Characterization and Pronase Susceptibility of the Na:K Pump-Associated Phosphoprotein of Human Red Blood Cells

1974 ◽  
Vol 63 (3) ◽  
pp. 305-323 ◽  
Author(s):  
Philip A. Knauf ◽  
Fulgencio Proverbio ◽  
Joseph F. Hoffman
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chemical Characterization ◽  
Polyacrylamide Gel ◽  
Transport Parameters ◽  
Intact Cells ◽  
Human Red Blood Cells ◽  
Polypeptide Band ◽  
Pronase Treatment

The phosphoproteins formed by incubation of red cell ghosts with [γ-32P]ATP in the presence of Mg and Na + Mg have been characterized by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The 32P-labeled phosphoprotein was seen as a single peak confined to the region of the diffuse 90,000 dalton polypeptide band; labeling with Na + Mg considerably increased the quantity of 32P-phosphoprotein contained in this band relative to labeling with Mg alone. Treatment of intact cells with Pronase known to partially hydrolyze the glycoproteins and the 90,000 daltons polypeptide did not change either the amount or the position of the 32P-phosphoprotein present in the gels. The molecular weight of the 32P-phosphoprotein is estimated to be 103,000. Pronase treatment of intact cells also did not significantly alter any of the transport parameters of the membrane such as the K pump flux, ouabain binding, or Na,K-ATPase. In contrast, treatment of ghosts with Pronase not only resulted in drastic alteration of the transport parameters but also inhibited the formation of the phosphoprotein under all conditions. Thus, while the Na:K pump is not intrinsically resistant to Pronase, those elements of the pump which are susceptible are not accessible from the outside of the cell. Further, SDS-polyacrylamide gel electrophoresis after Pronase treatment of intact cells results in a substantial increase in the purification of the phosphoprotein relative to that which was previously possible in ghosts.

scholarly journals Isolation of Some Platelet Membrane Glycoproteins

1977 ◽  
Author(s):  
K.J. Clemetson ◽  
S.L. Pfueller ◽  
A. Sturk ◽  
E.F. Lüscher ◽  
C.S.P. Jenkins
Keyword(s):  
Gel Electrophoresis ◽  
Wheat Germ ◽  
Lens Culinaris ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Platelet Membrane ◽  
Buffer System ◽  
Membrane Glycoproteins ◽  
Abrus Precatorius ◽  
Differential Binding

The platelet is surrounded by a pronounced glycocalix formed by carbohydrate moieties of the membrane glycoproteins. The number of glycoproteins of the outer platelet membrane is greater in number than had previously been reported : when solubilized membranes are analyzed by SDS-polyacrylamide gel electrophoresis the number of separated carbohydrate entities was found not only to be dependant on the concentration of acrylamide and of bisacrylamide used but also on the buffer system employed.The major platelet membrane glycoproteins have been solubilized and subjected to affinity chromatography on the lectins from Lens culinaris, wheat germ and Abrus precatorius. SDS-polyacrylamide gel electrophoresis in the presence and absence of a reducing agent together with the differential binding of the lectins to the glycoproteins permitted the distinction of at least seven glycoprotein entities. Using combinations of lectin columns, two platelet membrane glycoproteins have been isolated and others have been greatly purified.

scholarly journals Role of Surface Proteins in Vibrio cholerae Attachment to Chitin

1999 ◽  
Vol 65 (3) ◽  
pp. 1348-1351 ◽  
Author(s):  
Renato Tarsi ◽  
Carla Pruzzo
Keyword(s):  
Vibrio Cholerae ◽  
Gel Electrophoresis ◽  
Wheat Germ ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Molecular Sizes ◽  
Pronase E

ABSTRACT The role of surface proteins in Vibrio choleraeattachment to chitin particles in vitro was studied. Treatment ofV. cholerae O1 ATCC 14034 and ATCC 14035 with pronase E reduced the attachment of bacteria to chitin particles by 57 to 77%. A statistically significant reduction was also observed when the attachment to chitin was evaluated in the presence of homologous Sarkosyl-insoluble membrane proteins (MPs) (67 to 84%),N-acetylglucosamine (GlcNAc) (62%), the sugar that makes up chitin, and wheat germ agglutinin (40 to 56%), a lectin that binds GlcNAc. The soluble oligomersN,N′-diacetylchitobiose orN,N′,N"-triacetylchitotriose caused an inhibition of 14 to 23%. Sarkosyl-insoluble MPs able to bind chitin particles were isolated and visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; two of these peptides (molecular sizes, 36 and 53 kDa) specifically bind GlcNAc.

scholarly journals The quaternary structure of wheat-germ aspartate transcarbamoylase

1982 ◽  
Vol 203 (2) ◽  
pp. 413-417 ◽  
Author(s):  
R J Yon ◽  
J E Grayson ◽  
A Chawda ◽  
P J Butterworth
Keyword(s):  
Molecular Mass ◽  
Gel Electrophoresis ◽  
Wheat Germ ◽  
Quaternary Structure ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Aspartate Transcarbamoylase ◽  
Molecular Masses

1. The molecular mass of aspartate transcarbamoylase purified from wheat germ was found to be 101kDa by sucrose-density-gradient centrifugation, 103kDa by gel-filtration chromatography and 108kDa by polyacrylamide-gel electrophoresis. A mean value of 104 +/- 11kDa was obtained by pooling several replicate results from each method. 2. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate indicated a single size of polypeptide chain of mean molecular mass 37 +/- 4kDa. The ratio of the mean molecular masses of the active and denatured enzymes is 2.8.3. When the active enzyme was covalently cross-linked at a low protein concentration by dimethyl suberimidate, and then examined electrophoretically under denaturing conditions, three size species were observed to predominate, of apparent molecular masses 36, 77 and 106kDa respectively. 4. These results indicate that the intact, fully regulatory enzyme is a simple trimer, slightly larger than the trimeric ‘catalytic subunit’ of the aspartate transcarbamoylase from Escherichia coli [Weber (1968) Nature (London) 218, 1116-1118]. The prevalence of trimeric structures amongst carbamoyl-transferase enzymes is discussed.

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