Blue ultrafiltration

Jolly, R.C., Kosikowski, F.V. 1975b. A new blue cheese food material from ultrafiltrated skim milk and microbial enzyme - mold spore reacted fat. J. Dairy Sci. 58, 1272-1275. 

If the channel for Fl-FFF is utilized such that cross-flow is due to a solvent of different composition that has the solvent flowing in an axial direction, continuous separation of high-molar-mass components from low-molar-mass contaminants, migrating through the accumulation membrane, can be achieved. The ratio of cross-flow rate to axial-flow rate must be suitably adjusted. The function of a continuous Fl-FFF channel as a dialysis or ultrafiltration cell was described theoretically and demonstrated in practice for the separation of bovine serum albumin from low-molar-mass methylene blue [247]. 

A continuous Fl-FFF channel analogous to a dialysis cell or ultrafiltration cell [247] was described theoretically and later demonstrated in practice for the separation of bovine serum albumin from methylene blue, various viruses, proteins, and colloidal silica particles. 

Ascoxal (a mucolytic drug). Then the gastric juice was concentrated by ultrafiltration and subjected to star electrophoresis in veronal bufiFer of pH 8.6, r/2 0.033. The curtain was stained after oven drying with amido black, azocarmine, or bromophenol blue. Up to 10 protein fractions were localized on the curtain, including pepsin, albumin, and contaminant protease (trypsin ) derived from regurgitated duodenal secretion. Peptic... 

The inducible arsenite oxidase from the Eubacterium Alcaligenes faecalis (NCIB 8687) has been purified and characterized (22-24). Anderson et al. (24) isolated the enzyme from a sonicate of washed, lysozyme-treated cells that had been harvested in their late exponential growth phase. The sonicate was fractionated by gel filtration through DEAE-sepharose and active fractions concentrated by ultrafiltration. The purified enzyme was found to be monomeric with a molecular mass of 85 kDa. It consisted of two polypeptide chains in an approximate ratio of 70 30. The enzyme stmcture included one molybdenum, five or six iron atoms, and sulfide. Purification of the oxidase also led to recovery of azurin, a blue protein, which was rapidly reduced by arsenite in the presence of catalytic amounts of Aro, and a red protein. The red protein was a c-type cytochrome, which was reduced by arsenite in the presence of catalytic amounts of Aro and azurin. No reduction of the cytochrome occurred in the absence of Aro, but it did occur in the absence of azurin. Denaturation of Aro led to the release of a pterin cofactor characteristic of molybdenum hydroxylases. In intact cells of A. faecalis, the enzyme resides on the outer surface of the inner (plasma) membrane. The cytochrome and azurin may be part of an electron transfer pathway in the periplasm. 

The concentrated sample from the previous colunnn is loaded onto a colunm (5 X 12 cm) of Blue Sepharose (Pharmacia Biotech) equilibrated with buffer C. The column is eluted with a 1.4 liter linear gradient of 0 to 2 Af NaCl in buffer C and 50-ml fractions are collected. FNOR activity starts to elute as 1.5 A/ NaCl is applied. It should be noted that three peaks of the NBVOR assay are separated by this chromatography step. The first peak to elute contains 20% of the total activity and the enzyme responsible has not been characterized. The third peak to elute represents 40% or the NBVOR activity and in this case BV reduction is catalyzed by NADPH rubredoxin oxidoreductase (NROR). It is the second peak of NBVOR activity, which also contains about 40% of the total, that corresponds to FNOR, and this starts to elute as 1.7 Af NaCl is applied to the colunm. Fractions containing FNOR are combined (600 ml) and concentrated to 30 ml by ultrafiltration (PM30 membrane). 

Ultrafiltration of each catalyst with a 0.1 xm cellulose acetate/nitrate membrane (Millipore) revealed no blue CoPcTs in the filtrate. 

It should be noted, however, that this table is arranged with regard to solutions that Bechhold employed and does not necessarily represent the correct relations of the size of particles in colloidal solutions in general. In fact Prussian blue, colloidal iron oxide, and many other colloids may be prepared with particles varying so in size that the relation to hemoglobin would be quite different from that indicated by the table. Finally ultrafiltration is affected not only by the size of the particles, but also by other factors, such as adsorption, electric charge, etc. 

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