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 The subunit structure of the arom multienzyme complex of Neurospora crassa. Evidence from peptide ‘maps’ for the identity of the subunits

1978 ◽  
Vol 169 (2) ◽  
pp. 441-444 ◽  
Author(s):  
J Lumsden ◽  
J R Coggins
Keyword(s):  
Neurospora Crassa ◽  
Gel Electrophoresis ◽  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Subunit Structure ◽  
Multienzyme Complex ◽  
Peptide Maps

Evidence was obtained, from polyacrylamide-gel electrophoresis in the presence of urea and from peptide ‘mapping’ of specifically labelled cysteine-and methionine-containing peptides, that the two subunits of the arom multienzyme complex of Neurospora crassa are chemically very similar and possibly identical.

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 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.

Thyroxine increases neonatal mouse submandibular gland mRNA-directed synthesis of epidermal growth factor

1986 ◽  
Vol 64 (4) ◽  
pp. 290-296 ◽  
Author(s):  
Peter Walker
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Thyroid Hormones ◽  
Submandibular Gland ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Translation Product ◽  
Epidermal Growth ◽  
Peptide Maps

Thyroid hormones are known to modulate the concentrations of epidermal growth factor (EGF) in the mouse submandibular gland (SMG); this action is presumably mediated by the nuclear triiodothyronine receptor. To test the hypothesis that thyroid hormones act to increase SMG EGF concentrations by increasing the number of poly(A)+-specific mRNA, poly(A)+ RNA was isolated from SMGs of neonatal mice which had been treated daily from birth through to 21 days of age with thyroxine (T4, 0.4 μg/g body weight). Poly(A)+ RNA also was extracted from SMGs of intact 21-day-old mice which had received vehicle alone. No significant differences in total nucleic acid, total RNA, or poly(A)+ RNA yields were noted between the two groups of animals. The isolated poly(A)+ RNAs from T4-treated and control mice were translated in an in vitro wheat germ system. Although no significant differences in efficiency of [35S]cysteine incorporation into trichloracetic acid precipitable material were noted between the two poly(A)+ RNA preparations, a significantly greater proportion of radioactivity was immunoprecipitable by anti-EGF antiserum in the translation medium derived from T4-treated mice (17.2 ± 0.9%, mean ± SEM) than in that of control mice (7.3 ± 0.5%, P < 0.001). Polyacrylamide gel electrophoresis of the immunoprecipitates (IMMP) revealed the presence of three radioactive bands with apparent relative masses (Mrs) of 12 000, 9000, and 6000. The latter species comigrated with purified EGF, [125I]EGF, and an IMMP of a SMG extract. The translation product IMMPs following polyacrylamide gel electrophoresis were iodinated and digested with α-chymotrypsin. Autoradiograms, following high-voltage electrophoresis and ascending chromatography on thin-layer cellulose, showed a marked similarity of the peptide maps of purified EGF, the IMMP of a SMG extract, and the translation product IMMPs. Furthermore, the peptide maps of the Mr 12 000, 9000, and 6000 IMMPs were highly concordant, suggesting that the Mr 12 000 and 9000 species are structurally related to the Mr 6000 EGF species. These observations support the hypothesis that thyroid hormones increase SMG EGF concentrations by increasing the number of poly(A)+ RNA species coding for EGF.

scholarly journals Antigenic and antiheparin properties of human platelet factor 4 (PF4)

Blood ◽  
1975 ◽  
Vol 45 (4) ◽  
pp. 537-550
Author(s):  
N Nath ◽  
CT Lowery ◽  
S Niewiarowski
Keyword(s):  
Gel Electrophoresis ◽  
Human Platelet ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Platelets ◽  
Polyacrylamide Gel ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Heat Stable ◽  
Antiheparin Activity ◽  
Heat Stable Protein

Platelet factor 4 (PF4, a heparin-neutralizing protein) was isolated from washed human platelets. It was found to be homogenous by SDS- polyacrylamide gel electrophoresis, immunodiffusion, and immunoelectrophoresis, when tested with monospecific antibody produced in rabbits. PF4 is a heat-stable protein, but its antiheparin activity and antigenicity are destroyed by trypsin. The molecular weight of PF4 as calculated by amino acid analysis is approximately 8000 and by SDS- polyacrylamide gel electrophoresis with beta-mercaptoethanol, 7100 daltons. PF4 migrated to the cathode at pH 8.6. The interaction of PF4 with heparin resulted in the formation of a complex which migrated to the anode, as tested by immunoelectrophoresis. Incubation of purified PF4 with its antibody at 37 degrees C resulted in a loss of antiheparin activity. The presence of antiheparin activity and of PG4 antigen in material released during platelet aggregation by various agents and at various stages of the preparative procedure closely correlated. It has been concluded that PF4 antigen and antiheparin activity are two properties of the same protein. Comparison of human and pig PF4 revealed significant biochemical and antigenic differences.

Antigenic and antiheparin properties of human platelet factor 4 (PF4)

Blood ◽  
1975 ◽  
Vol 45 (4) ◽  
pp. 537-550 ◽  
Author(s):  
N Nath ◽  
CT Lowery ◽  
S Niewiarowski
Keyword(s):  
Gel Electrophoresis ◽  
Human Platelet ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Platelets ◽  
Polyacrylamide Gel ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Heat Stable ◽  
Antiheparin Activity ◽  
Heat Stable Protein

Abstract Platelet factor 4 (PF4, a heparin-neutralizing protein) was isolated from washed human platelets. It was found to be homogenous by SDS- polyacrylamide gel electrophoresis, immunodiffusion, and immunoelectrophoresis, when tested with monospecific antibody produced in rabbits. PF4 is a heat-stable protein, but its antiheparin activity and antigenicity are destroyed by trypsin. The molecular weight of PF4 as calculated by amino acid analysis is approximately 8000 and by SDS- polyacrylamide gel electrophoresis with beta-mercaptoethanol, 7100 daltons. PF4 migrated to the cathode at pH 8.6. The interaction of PF4 with heparin resulted in the formation of a complex which migrated to the anode, as tested by immunoelectrophoresis. Incubation of purified PF4 with its antibody at 37 degrees C resulted in a loss of antiheparin activity. The presence of antiheparin activity and of PG4 antigen in material released during platelet aggregation by various agents and at various stages of the preparative procedure closely correlated. It has been concluded that PF4 antigen and antiheparin activity are two properties of the same protein. Comparison of human and pig PF4 revealed significant biochemical and antigenic differences.

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