Direct Observation of Postadsorption Aggregation of Antifreeze Glycoproteins on Silicates
نویسندگان
چکیده
The adsorption of antifreeze glycoproteins (AFGP) from aqueous solution onto two different silicate minerals, muscovite mica and amorphous silica-titania, has been directly observed for the first time in situ using atomic force microscopy (AFM) and optical waveguide lightmode spectroscopy (OWLS). The former yields the lateral distribution and heights of adsorbed single molecules and massed adsorpta, and the latter enables the precise number of adsorbed AFGP per unit area of surface to be determined as well as the kinetics of adsorption and desorption. On both surfaces the AFGP were initially deposited as isolated molecules. On mica they remained as such and could be imaged as compact, globular objects, in contrast to the elongated form presumed to exist in solution. On silica-titania they subsequently formed isolated conical deposits containing large numbers of molecules. The relevance of these results to the adsorption of the AFGP on ice is discussed.
منابع مشابه
Purification and primary sequences of the major arginine-containing antifreeze glycopeptides from the fish Eleginus gracilis.
An Arg-containing antifreeze glycoprotein from the polar fish Eleginus gracilis was isolated, and the major components were purified to homogeneity. The general protocol for purification was chromatography of serum on DEAE-cellulose, followed by chromatography on a cation exchanger. DEAE-cellulose chromatography resulted in two fractions, A and B. Fraction A contained most of the antifreeze gly...
متن کاملAntifreeze glycoproteins from Arctic fish.
Four species of fish in the Barents Sea of the Arctic, north of Norway and Russia, were caught and examined for the presence of antifreeze proteins in their blood sera. Only one species of Arctic fish, the polar cod (Boreogadus saida), was found to contain an antifreeze protein. Antifreeze glycoproteins were isolated and characterized from the blood serum of the Arctic fish, and their structure...
متن کاملIce surface reconstruction as antifreeze protein-induced morphological modification mechanism.
The crystal growth process by which fish antifreeze proteins (AFPs) and antifreeze glycoproteins (AFGPs) modify the ice morphology is analyzed in the AFP-ice system. A newly identified AFP-induced surface reconstruction mechanism enables one-dimensional helical and irregular globular ice binding surfaces to stabilize secondary, kinetically less stable ice surfaces with variable face indices. No...
متن کاملAntifreeze glycoprotein from an Antarctic fish. Effects of chemical modifications of carbohydrate residues on antifreeze and antilectin activities.
Structural requirements for antifreeze and antilectin activities of the antifreeze glycoproteins from the Antarctic fish Trematomus borckgrevinki have been compared. Graded removal of different amounts of the disaccharide side chain by p elimination caused similar reductions in the capacities for depressing the freezing temperature of water (antifreeze activity) and for inhibiting hemagglutinat...
متن کاملEffects of Gnidilatimonoein, from Daphne mucronata, on the plasma membrane glycoproteins in two cancerous cell lines
Metastasis describes the ability of a tumor to invade normal tissue and generate secondary tumors at sites distant from the primary tumor. The mechanism responsible for the inhibition of tumor metastasis by different agents is at least partly associated with the ability to interfere with cellular functions such as adhesiveness, motility and invasiveness. Certainly effective treatment of metasta...
متن کامل