scholarly journals Differentiation-related changes in glycoprotein synthesis by human keratinocytes

1986 ◽  
Vol 237 (2) ◽  
pp. 519-525 ◽  
Author(s):  
G P R Roberts ◽  
J Brunt
Keyword(s):  
Cell Surface ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Keratinocytes ◽  
Polyacrylamide Gel ◽  
Galactose Oxidase ◽  
Glycoprotein Synthesis ◽  
Surface Labelling ◽  
Triton X

Human keratinocytes were cultured in media in which the Ca2+ concentration controlled the stage of differentiation. In media containing less than 0.1 mM-Ca2+ keratinocytes grew as a monolayer, but in the presence of 2mM-Ca2+ the cells differentiated and formed stratified colonies. Glycoproteins of both stratified and unstratified cells were radiolabelled by metabolic incorporation of radioactive precursors and by cell-surface labelling using galactose oxidase/NaB3H4. The radiolabelled keratinocytes were extracted with 0.5% Triton X-100, and the glycoproteins in both the Triton X-100-soluble and Triton X-100-insoluble fractions were analysed by polyacrylamide-gel electrophoresis in the presence of SDS. Two Triton X-100-soluble glycoproteins with high Mr values (greater than 200,000) were major glycoproteins in stratified keratinocytes, but were present in only trace amounts in unstratified keratinocytes. Characterization of these glycoproteins by examination of the effect of tunicamycin on their synthesis and the effect of neuraminidase on their migration characteristics showed that they were cell-surface sialoglycoproteins containing O-glycosidically linked oligosaccharides. Analysis of the adherent cytoskeletons left after Triton X-100 extraction of stratified and unstratified keratinocytes revealed that a glycoprotein of Mr 184,000 was decreased in stratified keratinocytes. Incubation of unstratified keratinocytes in high-Ca2+ medium resulted in a rapid modification of the glycoprotein of Mr 184,000, and it is suggested that this event may be related to desmosome formation and stratification.

scholarly journals Identification of an epidermal cell-adhesion glycoprotein

1985 ◽  
Vol 232 (1) ◽  
pp. 67-70 ◽  
Author(s):  
G P Roberts ◽  
J Brunt
Keyword(s):  
Cell Adhesion ◽  
Cell Surface ◽  
Epidermal Cell ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Keratinocytes ◽  
Intercellular Adhesion ◽  
Polyacrylamide Gel ◽  
Galactose Oxidase ◽  
Surface Labelling

Glycoproteins which mediate intercellular adhesion were studied by comparing the effects of trypsin and the neutral proteinase, Dispase, on human keratinocytes metabolically labelled with D-[1-14C]glucosamine or L-[1-3H]fucose. Whereas digestion of keratinocytes with trypsin/EDTA resulted in loss of both cell-substratum and intercellular adhesion, only cell-substratum adhesion was disrupted by incubation with Dispase. Analysis of the radiolabelled glycoproteins by polyacrylamide-gel electrophoresis revealed that a glycoprotein of Mr 126 000 was cleaved by trypsin/EDTA, but not by Dispase. Surface labelling of keratinocytes with galactose oxidase/NaB3H4 confirmed that this glycoprotein was exposed on the cell surface. Addition of lmM-Ca2+ prevented dispersion of keratinocytes by trypsin and concomitantly protected the glycoprotein of Mr 126 000 from digestion. These results indicate that this glycoprotein has an important role in mediating intercellular adhesion of keratinocytes.

scholarly journals Glycoproteins and glycosaminoglycans synthesized by human keratinocytes in culture. Their role in cell-substratum adhesion

1983 ◽  
Vol 212 (2) ◽  
pp. 355-363 ◽  
Author(s):  
G P Roberts ◽  
L Jenner
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Human Keratinocytes ◽  
Cytoskeletal Proteins ◽  
Galactose Oxidase ◽  
Surface Labelling ◽  
Triton X ◽  
Sulphated Glycosaminoglycan

Glycoproteins and proteoglycans synthesized by human keratinocytes in medium containing D-[1-14C]glucosamine were extracted and analysed by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. Extraction of the labelled keratinocytes with 0.5% Triton X-100 removed most of the glycoconjugates and left the cytoskeleton and nuclear residue adherent to the substratum. In addition to the cytoskeletal proteins, there was a relatively simple profile of glycoproteins and glycosaminoglycans associated with this adherent cytoskeleton. These consisted of eight glycoproteins in the mol.wt. range 99000-232000, five proteins in the keratin region (mol.wt. 42000-61000), hyaluronic acid and a sulphated glycosaminoglycan. Surface labelling of the keratinocytes with galactose oxidase (with or without neuraminidase)/KB3H4 revealed that many of the glycoproteins were exposed on the cell surface. The importance of the glycoproteins and proteoglycans in attaching the keratinocytes to the substratum was examined by studying their expression after incubation in medium containing tunicamycin and their degradation after digestion with trypsin and hyaluronidase. These studies, together with an examination of the glycoconjugates released by sequential extraction with 0.5% Triton X-100 followed by 0.2% sodium dodecyl sulphate, revealed that the glycoprotein of mol.wt. 232000 has an important role in mediating the attachment of keratinocytes to the substratum.

scholarly journals Surface glycoproteins of human spermatozoa

1986 ◽  
Vol 82 (1) ◽  
pp. 11-22
Author(s):  
M. Kallajoki ◽  
I. Virtanen ◽  
J. Suominen
Keyword(s):  
Plasma Membrane ◽  
Gel Electrophoresis ◽  
Soluble Fraction ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Human Spermatozoa ◽  
Galactose Oxidase ◽  
Sperm Cells ◽  
Neuraminidase Treatment ◽  
Triton X

The surface membrane glycoprotein composition of human spermatozoa has been studied by introducing radioactive label into galactosyl (Gal) and N-acetylgalactosaminyl (GalNAc) residues by using the galactose oxidase/NaB3H4 method. Triton X-100 extracts and Triton X-100-resistant cytoskeletal residues were subjected to analysis by polyacrylamide gel electrophoresis. The distribution of the radiolabel in sperm cells was studied by light-microscopic auto-radiography. The grains were evenly distributed on the cells by the labelling methods used. The Triton X-100 treatment did not affect sperm morphology at the light-microscopic level, but in transmission electron microscopy the plasma membrane covering the acrosome was removed totally, together with most of the acrosomal membranes and acrosomal contents. Plasma membrane residues were, however, always found in the postacrosomal region. Borohydride alone without oxidative pretreatment labelled two polypeptides of molecular weights (Mr) 48,000 and 43,000 in the Triton X-100-soluble fraction. When the Gal/GalNAc residues were labelled by galactose oxidase pretreatment 120,000, 105,000, 78,000 and 68,000 Mr glycoproteins were revealed. When additional neuraminidase treatment was used to remove terminal sialic acid residues, the total labelling intensity was increased two- to fivefold and additional 36,000 and 20,000 Mr glycoproteins were revealed. The Triton X-100-resistant cytoskeletal residue contained 53–75% of the total radioactivity bound in sperm cells. When these components were analysed by polyacrylamide gel electrophoresis, all the major bands found in the Triton X-100-soluble fraction were detected and also some radioactivity was incorporated into the major bands visualized by protein staining. In the present study we describe several human sperm glycoproteins, which seem to be distributed evenly on the sperm cells. Detergent extraction, producing cytoskeletal models, appeared to leave most of the glycoproteins detectable in the extraction residues also with the apparent enrichment of a single 68,000 Mr glycoprotein.

scholarly journals The Characterization of Pig Platelet Membrane Proteins: Studies on Membrane-Associated Actin and the Surface-Associated Phosphodiesterase Activity

1977 ◽  
Author(s):  
D. G. Taylor
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Surface Membrane ◽  
Polyacrylamide Gel ◽  
Molecular Weight Range ◽  
Platelet Surface ◽  
Prominent Component ◽  
Triton X ◽  
Sepharose 4B

Analysis of the polypeptides of a pig platelet surface membrane fraction by SDS-polyacryl-amide gel electrophoresis revealed the presence of approx. 12 components (molecular weight range 12000–200000).A component of 43–45,000 daltons was particularly prominent and this has been identified as actin, and shown to be similar in many respects to the cytoplasmic protein. The membrane-associated actin has been isolated as a pure band by preparative SDS-polyacrylamide gel electrophoresis and analysis of its amino acid composition, although very similar to that of actin purified from whole platelets, showed a much lower content of 3-methylhistidine (approx. 0.05 residues/mole compared with 0.62 residues/mole). The surface membrane-associated phosphodiesterase (towards bis-(p-nitropheny1) phosphate) has also been partially characterised. This enzyme activity can be completely solubilised from the membrane using 0.5% Triton X-100, and can then be isolated as a single peak on Sepharose 4B. The separated enzyme fraction showed considerable purification over the original membrane as illustrated by SDS-polyacrylamide gel electrophoresis with the prominent component being the 95,000 dalton polypeptide. Our studies have also shown that this phosphodiesterase is inhibited competitively by ADP and ATP.

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

Characterization of immunoreactive proteins of Setaria cervi isolated by preparative polyacrylamide gel electrophoresis

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Priyanka Priyadarshi ◽  
Piyush Dravid ◽  
Inayat Hussain Sheikh ◽  
Sunita Saxena ◽  
Ashish Tandon ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Complex Mixtures ◽  
Setaria Cervi ◽  
Antigenic Proteins ◽  
Specific Antigens

AbstractFilarial parasites are complex mixtures of antigenic proteins and characterization of these antigenic molecules is essential to identify the diagnostically important filaria-specific antigens. In the present study, we have fractionated the somatic extracts from adults of

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