A review of: “Membrane Mimetic Chemistry J. H. Fendler John Wiley and Sons,New York, 1982 Hardcover, 522 pages, $59.95”

Formycin B [9-deazainosine] was reacted with epoxy-activated Sepharose 68 to form an affinity resin for purine nucleoside phosphorylase (PNPase). This resin had a large capacity (7,600 units/ml) for the enzyme from Escherichia coli. Enzyme retention was dependent on high ionic strength. Although this property is reminiscent of hydrophobic interaction chromatography, analogous resins prepared with pseudouridine or monoethanolamine instead of with formycin B, did not retain the enzyme even at high ionic strength. Furthermore, hypoxanthine facilitated elution of the enzyme from the resin. It appeared, therefore, that the enzyme was not bound simply by hydrophobia interactions. A simple two-step purification procedure for PNPase from Escherichia coli was devised using this resin. Overall recovery was 50%, and purity of the final preparation was greater than 95%. This resin was also useful in the purification of PNPase from human erythrocytes. The ether linkage between formycin B and Sepharose 6B, together with the carbon-to-carbon linkage between the pentose and heterocyclic moieties of formycin B, provided stability to both chemical and enzymatic degradation. After 5 years of use and exposure to a variety of biological preparations, the resin showed no detectable decrease in its ability to bind PNPase.     

A Review of: “Centrifugation in Biology and Medical Science,P. Sheeler,Wiley/Interscience,New York, 1981; hardbound, 269 pages, $35.00”

ABSTRACT

Peroxidases (E.C. 1.11.1.7., hydrogen donor oxidoreductase) utilize hydrogen peroxide or substituted peroxides for the oxidation of a large number of substrates. Peroxidases are widely distributed and have been isolated from many higher plants (1). The wide distribution of the enzyme suggests that it could be of great biological importance, but the physiological functions and metabolic control of these enzymes are still poorly understood. The simultaneous presence of amine oxidase and peroxidase in cell walls suggests that the peroxide generated on oxidation of the amines could be utilized by the peroxidase (2,3). Recently we have purified an amine oxidase from Hordeum vulgare (4) and we have attempted to purify the peroxidase in order to study in vitro the reconstituted coupled system. β-glucosidase (β-D-glucoside glucohydrolase E.C. 3.2.1.21.) is capable of transforming glucosides in glucose and the corresponding aglycone or disaccarides as cellobiose, sophorose, gentiobiose. This enzyme is widely distributed in plants, fungi, bacteria, yeasts and animals (5, 6). In the homogenate of Hordeum vulgare seedlings we also found β-glucosidase activity and also attempted to purify β- glucosidase. This enzyme copurified whit peroxidase up to the last step. We report here the isolation of peroxidase and β-glucosidase from Hordeum vulgare see-dlings: some molecular and kinetic properties are given.     

A Review of: “Immobilized Enzymes: Research and Development,I. Chibata,Ed., Kodansha,Ltd., Tokyo; John Wiley and Sons/HaIsted Press,New York, 1978; hardbound, 284 pages, $35.00”

A device of a new dish for the culturing of cells on a biological substrate, the eye lens capsule, is described. With the aid of this dish it is possible to investigate the possible interrelationships between the cell substratum and various biochemical characteristics of the cell. It is shown that the protein biosynthetic pattern differs between lens cells cultured on lens capsule as a substrate and cells cultured on foil. Moreover, the new dish opens the possibility to culture epithelial cells on a lens capsule, which gives an alternative to the culture of these cells on a collagen substrate.