Glycoproteins isolation

The biotinylated glycans on the cell surfaces subsequently may be probed with (strept)avidin reagents to detect the azido-sialic acid modifications. Alternatively, the cells may be lysed and the glycoproteins isolated using an immobilized (strept)avidin or monomeric avidin affinity resin. 

Bezkorovainy, A. 1965. Comparative study of the acid glycoproteins isolated from bovine serum colostrum and milk whey. Arch. Biochem. Biophys. 110, 558-567. 

Kanno, C., Shimizu, M. and Yamauchi, K. 1977. Polydispersity and heterogeneity of the soluble glycoprotein isolated from bovine milk fat globule membrane. Agr. Biol. Chem. (Japan) 41, 83-87. 

Blix (8, 9, 10) after mild acid hydrolysis of bovine submaxillary glycoprotein isolated a crystalline material called sialic acid which gave the direct and indirect Ehrlich reactions. Table I shows that similar substances were isolated by other workers from glycolipids (11, 12), other... 

The proteins that are responsible for mitochondrial Ca2+ uptake have not been identified with certainty. Various glycoproteins isolated from mitochondria are probably Ca2+ receptor proteins rather than Ca24 transporters. However, a 3000 molecular weight Ca2+-binding protein has been isolated from the inner membrane of calf heart mitochondria which has properties appropriate... 

S.N. Bhattacharyya. S. Sahu and W.S. Lynn, Structural studies on a glycoprotein isolated from alveoli of patients with alveolar proteinosis, Biochem. Biophys. Acta 427 (1976) 91-106. 

Although hyperlipidemia may be partly reversed by the increase of plasma oncotic pressure with dextran infusion, decreased albumin and plasma oncotic pressure cannot fully explain nephrotic hyperlipidemia. In analbuminemic rats, lipid changes are different from those in nephrotic subjects (D4). There may be a direct causal link between proteinuria and lipid abnormalities because a 1 -acid glycoprotein isolated from urine of nephrotic patients may correct the impaired lipolysis of nephrotic rats (SI 6, K12). Thus, impaired lipoprotein metabolism may be caused by the loss of some regulatory substance into urine due to increased glomerular permeability. 

The main drawback of glycoprotein isolation and extraction from natural sources is the complexity of purification arising from their expression as mixtures of different glycoforms [6], These protein isoforms differ only with respect to the number, type of attached gly cans, or gly cosy lation site yet may result in many hundreds of variants. Homogeneous glycoforms cannot be readily accessed from natural sources because glycosylation, as with other posttranslational modifications, is not directly genetically driven. 

Fig. 11. The effects of acrylamide gel concentration on the mobilities of glycoproteins isolated from Trematomus borchgrevinki. Rm is the relative mobility. From DeVries et al. (1970), reproduced with permission.

The flounder protein has been shown from circular dichroism measurements to possess a large proportion (—85%) of the a-helical conformation in aqueous solution (pH 8.0) at — 1°C (Ananthanarayanan and Hew, 1977a). The helical content decreases as the temperature is raised (Fig. 32). Viscosity data at — 1°C indicate an asymmetric shape for the protein molecule compatible with its high helical content. Thus, the secondary and tertiary structure of this protein, as well as its primary structure, are found to be different from its counterpart glycoproteins isolated from other fish. No data are available concerning the assumption that this highly helical structure at — 1°C is related to its function. 

Glycoproteins and polysaccharides are the final class of phytochemicals compounds important to Echinacea. The glycoproteins isolated from / . purpurea and / . angustifolia roots range from 17 to 30 kDa and contain 64-84% arabinose (Bauer, 1999a, 2000). Limited research has been completed on the glycoproteins, thus the reader is directed to the review by Bauer (1999a, 2000) for further information. 

Another relevant example is the convergent assembly of a biantennary heptasac-charide motif 39 of a human glycoprotein isolated from seminal plasma. It was accomplished by Ley s and Wong s groups in a 2 + 3 + 2 fashion as depicted69... 

Fig. 12. Proposed primary structure of the NETNES glycoprotein isolated from T. cruzi (epimastigote). Ref. 22.

Kdn-rich glycoprotein isolated from vitelline envelope and/or female ovarian fluid of rainbow trout... 

M25. Matsushiro, T., Nemoto, T., Endo, M., and Yosizawa, Z., Glycoproteins and sulfated glycoproteins isolated from human bile. Clin. Chim. Acta 30, 645-655 (1970). 

An unusual glycoprotein, isolated from the spores of Ustilago tritia, contains residues of L-fucose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, D-galactose, D-glucose, and D-mannose. ... 

The glycoproteins isolated from complete and defective rabies viruses contain the same monosaccharides, viz. neuraminic acid, D-galactose, D-mannose, L-fucose, and 2-acetamido-2-deoxy-D-glucose. The isoelectric points, molecular sizes, and glycosylation patterns of the two groups of glycoproteins were found to differ. 

A DNA double-helix unwinding glycoprotein, isolated from roe-deer liver, contains residues of L-fucose, D-xylose, and D-mannose together with two unidentified sugars." The glycoprotein is involved in the unwinding of adenine-thymine deoxyribose base pairs in DNA. 

Glycoproteins, isolated from granulation tissue and fractionated by gel filtration and ion-exchange chromatography, inhibit collagen synthesis in rat... 

Glycoproteins isolated from the erythrocytes of rhesus monkeys inhibit haemagglutination by measles virus. 

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