Of protein on porous glass

Adsorption and Chromatography of Proteins on Porous Glass Activity Changes of Thrombin and Plasmin Adsorbed on Glass Surfaces... 

Adsorption of proteins on porous glass varied with the protein, the buffer and the pH of the buffer. Based on these differences, porous glass can be used as an adsorbent for the separation of proteins by adsorption chromatography (, ). The amounts of basic amino acids, -icleosides, cations, and proteins adsorbed were about 4-5pmol/100 m (22-23). These results indicate that these materials adsorb on the surface as monolayers. 

MIZUTANI Adsorption and Chromatography of Proteins on Porous Glass... 

The amounts of protein adsorbed on porous glass at various pH were studied (3 ), Albumin was adsorbed the most at pH 5, lysozyme at pH 11, chymotrypsin at pH 8 these values correspond to the iso-... 

From the standpoint of blood clotting on the surfaces of artificial organs, the activity and structural changes of proteins bound on surfaces have been studied (36-41). The enzyme used in our studies were thrombin, plasmin, trypsin, phosphatase and peroxidase. Thrombin and plasmin are, respectively, key components of the coagulation and fibrinolytic systems. Kinetic parameters were obtained by direct measurement of the activities of enzymes bound on porous glass by mixing the porous glass with solutions of the substrate. 

The adsorption method is the simplest one and is often used in bioelectrocatalysis research. Essentially it involves the incubation of protein in the carrier suspension with the subsequent washing of the nonadsorbed protein. Adsorption of proteins on different types of surfaces is effected due to electrostatic, hydrophobic, and dispersion interactions. The most popular carriers are carbon, soot, clays, aluminum oxide, silica gel, and glass. The optimal inert carrier is glass. It has recently been shown that porous glass with calibrated pore size can be used for immobilization of enzymes by adsorption. An interesting method of immobilization by adsorption has been proposed in which lipid is first adsorbed on carbon or silica gel and then the enzyme is adsorbed on the so-called soft surface of the lipid. 

Both proteins and nucleic acids may be immobilized to a variety of solid supports. For high density microarrays, glass slides are the preferred substrates because of their flatness and optical properties. Better spot resolution is also possible on nonporous glass as opposed to porous membranes, primarily due to a reduction in diffusion at the surface-liquid interface. However, keep in mind that spot (droplet) diffusion can occur on most substrates by the actions of surfactants and other wetting agents including proteins. Control of spot size and morphology is required in order to achieve reproducible and reliable results with microarrays. 

The reasons for selecting pancreatic DNase I as one of the two representative of mammalian DNases are to a large extent historical. Deoxyribonuclease I was the first enzyme to be recognized as specific for DNA (18-15), the first DNase to produce 5 -monoesterified products (16, 17), the first DNase to be crystallized (18), the first DNase to have a specific protein inhibitor (19-23), the first DNase shown to produce nicks on one strand in preference to scission of both strands (24, 25). A new first has been added recently (25a) DNase I was covalently coupled to porous glass, thus supplying an insoluble DNase. 

In a similar approach, a pretuned glass encased microchip set to emit a unique binary code is placed in a polypropylene tea bag loaded with polystyrene beads. Using a modified split synthesis approach, a 125-membered tripeptide library N-capped as the /r-carboxy-cinnamic acid amide was prepared on Rink resin. Each porous reactor contained a radio frequency transporter which successfully defined the structure of two inhibitors of protein tyrosine phosphatase [37],... 

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