Isolation and characterization of a high-molecular-weight glycoprotein from the endometrium of porcine uteri

A novel glycoprotein was isolated from the endometrium of porcine uteri. This high-molecular-weight glycoprotein consisted of 25% of protein and 73% of carbohydrate. The carbohydrate composition was quite characteristic in that equimolar N-acetylglucosamine and galactose were major constituents. Its unique nature makes it distinguishable from hitherto-reported glycoproteins.     

Effect of aloe lectin on deoxyribonucleic acid synthesis in baby hamster kidney cells

A homogeneous glycoprotein (mol. wt 40,000) containing 34% carbohydrate was isolated from Aloe arborescens var. natalensis. At a concentration of 5 micrograms/ml, this glycoprotein was shown to stimulate deoxyribonucleic acid (DNA) synthesis in baby hamster kidney (BHK) cells and to have the properties of a lectin which reacts with sheep blood cells. The chemical and physical properties of the glycoprotein (aloe lectin) are also discussed.     

Effect of aloe lectin on deoxyribonucleic acid synthesis in baby hamster kidney cells

Summary A homogeneous glycoprotein (mol.wt 40,000) containing 34% carbohydrate was isolated fromAloe arborescens var.natalensis. At a concentration of 5 g/ml, this glycoprotein was shown to stimulate deoxyribonucleic acid (DNA) synthesis in baby hamster kidney (BHK) cells and to have the properties of a lectin which reacts with sheep blood cells. The chemical and physical properties of the glycoprotein (aloe lectin) are also discussed.     

New lectin receptors in carcinoembryonic antigen (CEA).

The glycoprotein CEA (carcinoembryonic antigen) carries carbohydrate groups, which react with the plant lectins from Agaricus bisporus, Arachis hypogaea (peanut), with Tridacnin from invertebrate clams and with the anti-A lectins from snails. Accordingly, it has cryptantigenic structures, which correspond to the T or T-like antigen, the Tridacnin receptor and to the so called A-like antigen.     

New lectin receptors in carcinoembryonic antigen (CEA)

Summary The glycoprotein CEA (carcinoembryonic antigen) carries carbohydrate groups, which react with the plant lectins fromAgaricus bisporus, Arachis hypogaea (peanut), with Tridacnin from invertebrate clams and with the anti-A lectins from snails. Accordingly, it has cryptantigenic structures, which correspond to the T or T-like antigen, the Tridacnin receptor and to the so called A-like antigen.Acknowledgment. This work has been supported by Landesamt für Forschung NRW.     

The role of glycosylation in protein antigenic properties

Glycosylation of proteins is a common event and contributes to protein antigenic properties. Most data have been obtained from model studies on glycoprotens with well-defined structure or synthetic glycopeptides and their respective monoclonal antibodies. Antibodies raised against glycoprotein antigens may be specific for their carbohydrate units which are recognized irrespective of the protein carrier (carbohydrate epitopes), or in the context of the adjacent amino acid residues (glycopeptidic epitopes). Conformation or proper exposure of peptidic epitopes of glycoproteins is also frequently modulated by glycosylation due to intramolecular carbohydrate-protein interactions. The effects of glycosylation are broad: glycosylation may 'inactivate' the peptidic epitope or may be required for its reactivity with the antibody, depending on the structure of the antigenic site and antibody fine specificity. Evidence is increasing that similar effects of glycosylation pertain to T cell-dependent cellular immune responses. Glycosylated peptides can be bound and presented by MHC class I or II molecules and elicit glycopeptide-specific T cell clones. Received 5 July 2001; received after revision 9 October 2001; accepted 11 October 2001     

Extraction and purification of brain glycoprotein NSA3 by binding with hyaluronic acid

Brain glycoprotein NSA3 was found to bind to immobilised hyaluronic acid. The binding was reversible and gave pure antigen (99%) in high yields (80%). The binding was suppressed by incubating the affinosorbent with hyaluronidase. It was not suppressed by trypsin. The presence of glycosaminoglycans other than hyaluronic acid in the sample did not inhibit the binding. This property is relevant to those already known for the brain glycoprotein NSA3, and to its localisation at the nodes of Ranvier. We propose to coin the name hyaluronectin for the brain glycoprotein NSA3.     

Purification and partial characterization of a human plasma α1-heteroglycan

Summary A heteroglycan was purified from human plasma and partially characterized in terms of its major properties. It is noteworthy that the carbohydrate content of this blood constituent is unusually high (75%).This study was supported by grants from the National Institutes of Health (GM-10374), US Public Health Service.     

Carbohydrate composition of the human cataractous lenses

Summary Specific chemical assays, including carbohydrate, hexosamines and hexuronic acid, were determined on the lens insoluble albumoid. It was noticed that the carbohydrate composition varies with age. The significance of carbohydrate in the lens in discussed.This work was supported by the College of Medicine of the University of Lagos, and financed by the British Council. The work was undertaken at the Department of Chemistry and Applied Chemistry, University of Salford, Salford (England).Special thanks are expressed to Dr L. R. Croft and Prof. G. I. Phillip for their help, support and encouragement throughout this study.     

Membrane fractions of rabbit granulocytes. 1. The presence of ouabain-sensitive ATPase and the electrophoretic patterns.

In one or two membrane fractions isolated from the homogenate of casein-induced rabbit granulocytes ouabain-sensitive ATPase activity was found definitely. Electrophoretic patterns of these membrane fractions showed no significant differences in staining for carbohydrate and protein.     

Association of brain glycoprotein (NSA 3) with neuronal membranes and with the nodes of Ranvier]

The localisation of brain glycoprotein NSA 3 was studied by means of indirect immunofluorescence on alcohol fixed, paraffin embedded sections of Rat brain. These techniques allowed the localisation of NSA 3 to the membrane of some (about 10%) of the neurons. In the white matter, the patterns were in agreement with the localisation of the Ranvier nodes. The nodes of Ranvier were also stained in peripheral nerves.     

Immunochemical study of protein anomalies in platelets of patients with Glanzmann's thrombasthenia and Bernard-Soulier syndrome]

Crossed immunoelectrophoresis of "Triton X-100" solubilized proteins from (125I) iodinated normal and abnormal (Bernard-Soulier and thrombasthenic) platelets was performed using rabbit antibodies raised against whole, normal platelets. In Bernard-Soulier platelets neither of the two surface oriented forms of GP I, glycocalicin and glycoprotein Ib (band 13) were detected. In two patients with type I thrombasthenia, the most prominent precipitate (No. 16) and platelet fibrinogen (No 24) were not detected whereas in one patient with type II thromblasthenia, fibrinogen was normally detected and the amount of protein 16 was around 15% of the normal level. The alloantibody IgG L..., able to induce a "thrombasthenic-like" reactivity in normal human platelets, has been shown to be directed against protein 16.     

Evaluation of participation of glucose in elevation of glycemia of scorpion (Heterometrus fulvipes) caused by the hyperglycemic principle of the scorpion and crab

Summary A single injection of the hyperglycemic principle obtained from scorpion cephalothoracic ganglionic mass causes an elevation of glycemia in the scorpionH. fulvipes in which little glucose is involved (10.8%). With the crustacean hyperglycemic principle, the elevation of glycemia is initially almost exclusively contributed by glucose (glucose is 92% of total carbohydrate at 2 h post injection); 6 h after treatment, non-glucose carbohydrates appear to participate in the elevation of glycemia.Acknowledgments. We wish to express our gratitude to CSIR, New Delhi for providing financial support to P.S.R., Reprint requests should be addressed to Prof. R. Ramamurthi.     

Isolation and partial characterization of receptor sites of normal human lymphocytes for lectins]

Glycoproteins of the lymphocyte surface are involved in many membrane mediated events. Their specific carbohydrate determinants might interact with lectins. Purification of macromolecules released from normal human lymphocytes by trypsin was performed using gel filtration and affinity properties for Ricinus sanguineus agglutinin. Some structural and biochemical characteristics are given. Relation to HLA determinants and surface immunoglobulins is discussed.     

Solubilization and characterization of a ouabain-sensitive protein from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) in cat cardiac muscle

A new glycoprotein of 31,500 dalton, which has a high affinity for ouabain, and is independent of (Na+-K+)-ATPase, was solubilized from transverse tubule membrane and junctional sarcoplasmic reticulum complexes (TTM-JSR) of cat cardiac muscle. This protein could be extracted only in small amounts from sarcolemma-plasma membrane (SLM-PL) fragments, suggesting that it indeed originates from the TTM-JSR.     

Improved separation at low temperature of glycoproteins by Con A-Sepharose affinity chromatography in the presence of sodium dodecyl sulfate (SDS)

The Con A-Sepharose affinity chromatography of glycoproteins was even more effective at 4 degrees C than that at room temperature (26-28 degrees C) in the presence of sodium dodecyl sulfate (SDS). Application of this methodology to the separation of several glycoproteins from SDS-solubilized membrane proteins in rat cerebellum, including a glycoprotein characteristic of the Purkinje cells, was successful.     

Isolation of a protease from the cell-free medium of in vitro cultured mammary carcinoma.

Trypsin-like protease with wide spectrum of enzymatic activities have been isolated from cell-free medium from in vivo cultured human mammary carcinoma cells, and from peripheral blood lymphocytes of patients with mammary carcinoma cultured in presence of cell-membrane carcinoma-associated glycoprotein.     

Isolation and partial characterization of a phytotoxic glycoprotein from culture filtrates ofRhynchosporium secalis

Summary Rhynchosporium secalis (Oud.) Davis produces a phytotoxic compound with a mol. wt of 275×10³ which is able to induce chlorotic symptoms in both susceptible and resistant barley leaves. Collectively, the data suggest that the toxin is a glycoprotein. Mild base treatment, by elimination, indicates that threonine and serine are involved in o-glycosidic linkages with the carbohydrate moiety. Sugar residues occur in the molecule in the ratio of mannose, rhammnose, galactose, glucosamine 13.6111.Acknowledgments. We acknowledge the assistance of Mr M. McNeil and P. Albersheim in doing the sugar analyses shown in this report. Financial support for this project was provided by a BARD grant 1-31-79, the French government, and the Montana Ag. Expt. Station.     

Isolation of a protease from the cell-free medium of in vitro cultured mammary carcinoma

Summary Trypsin-like protease with wide spectrum of enzymatic activities have been isolated from cell-free medium from in vitro cultured human mammary carcinoma cells, and from peripheral blood lymphocytes of patients with mammary carcinoma cultured in presence of cell-membrane carcinoma-associated glycoprotein.     

Species difference in the effects of proteolytic enzymes on red cell membrane

Summary Pronase and -chymotrypsin digested the major glycoprotein in the human and mouse red cell membranes and in SDS gel electrophoresis the glycoprotein disappeared accompanied by the appearance of a new band of lower mol.wt. However in the membranes of sheep, rat and rabbit, no digestion was demonstrated. The effects of pronase on anion permeability were almost identical for human and animal erythrocytes.