Author
Gilbert Ashwell
Other affiliations: Albert Einstein College of Medicine, United States Public Health Service, Boston Children's Hospital
Bio: Gilbert Ashwell is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Asialoglycoproteins & Sialic acid. The author has an hindex of 48, co-authored 109 publications receiving 11338 citations. Previous affiliations of Gilbert Ashwell include Albert Einstein College of Medicine & United States Public Health Service.
Papers published on a yearly basis
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1,066 citations
TL;DR: Evidence is presented to indicate a generalized role for the terminal sialic acid residues of circulating glycoproteins of desialylated plasma proteins inducers of gonadotropic hormones and follicle-stimulating hormone.
1,036 citations
TL;DR: It is concluded that the latter polysaccharide has a central role in the organization of the yeast cell wall and the possible mechanism of synthesis and physiological significance of the cross-links is discussed.
607 citations
TL;DR: Human diferric transferrin binds to the surface of K562 cells, a human leukemic cell line, and the loss of surface receptors upon internalization never exceeds 60-70% of the initial binding capacity suggests that receptors enter the cell with ligand but are replaced so as to maintain a constant, albeit reduced, receptor number on the cell surface.
576 citations
TL;DR: A mechanism to account for the recycling of transferrin subsequent to internalization and residence within an acidic nonlysosomal organelle where iron is removed is proposed.
Abstract: The binding of apotransferrin to the transferrin receptor on the surface of human leukemic K562 cells was found to be significantly less tight than that of the holoprotein, diferric transferrin. The finding that both ligands displayed linear Scatchard plots with similar receptor number (approximately equal to 150,000 per cell) and mutually inhibit each other's binding suggested that they bind to the same receptor. Both the dissociation and association rate of apotransferrin were markedly increased (28-fold and 15-fold, respectively) at pH 7.2 compared to pH 4.8. Using the values of these binding parameters, we propose a mechanism to account for the recycling of transferrin subsequent to internalization and residence within an acidic nonlysosomal organelle where iron is removed.
576 citations
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TL;DR: The force required to separate two cells is shown to be greater than the expected electrical forces between cells, and of the same order of magnitude as the forces required to pull gangliosides and perhaps some integral membrane proteins out of the cell membrane.
Abstract: A theoretical framework is proposed for the analysis of adhesion between cells or of cells to surfaces when the adhesion is mediated by reversible bonds between specific molecules such as antigen and antibody, lectin and carbohydrate, or enzyme and substrate. From a knowledge of the reaction rates for reactants in solution and of their diffusion constants both in solution and on membranes, it is possible to estimate reaction rates for membrane-bound reactants. Two models are developed for predicting the rate of bond formation between cells and are compared with experiments. The force required to separate two cells is shown to be greater than the expected electrical forces between cells, and of the same order of magnitude as the forces required to pull gangliosides and perhaps some integral membrane proteins out of the cell membrane.
4,058 citations
TL;DR: A rapid method based on a defined methanol-chloroform-water mixture for the quantitative precipitation of soluble as well as hydrophobic proteins from dilute solutions (e.g., column chromatography effluents) has been developed.
3,842 citations
14 Apr 2006
3,340 citations
TL;DR: The chemical structure and relevant biological properties of chitosan for regenerative medicine have been summarized as well as the methods for the preparation of controlled drug release devices and their applications.
2,312 citations
TL;DR: A method is described which is specific for the extraction of lipopolysaccharides from R form bacteria, which consists of aqueous phenol, chloroform and petroleum ether.
Abstract: A method is described which is specific for the extraction of lipopolysaccharides from R form bacteria. The extraction mixture which is monophasic, consists of aqueous phenol, chloroform and petroleum ether. R form lipopolysaccharides (glycolipids). due to their lipophilic nature, are completely soluble in the mixture. S and T form lipopolysaccharides as well as proteins, nucleic acids, and polysaccharides, are insoluble, and they are excluded from the extracts. The method is mild, as it can be carried out at below 10°. The yields are generally higher than those obtained by phenol-water extraction, and the products are usually water-soluble. Lipopolysaccharides have been successfully extracted from all R form bacteria so far attempted.
1,858 citations