Crude enzyme preparations

Enzyme-mediated chiral sulfoxidation has been reviewed comprehensively in historical context [188-191]. The biotransformation can be mediated by cytochrome P-450 and flavin-dependent MOs, peroxidases, and haloperoxidases. Owing to limited stability and troublesome protein isolation, a majority of biotransformations were reported using whole-cells or crude preparations. In particular, fungi have been identified as valuable sources of such biocatalysts and the catalytic entities have not been fully identified in all cases. 

Rapidase C-80 (Gist -brocades) was used as enzyme source. The fractionation procedure of the crude preparation included chromatography on Bio-Gel PIO (100-200 mesh), DEAE-Bio-Gel A, and Bio-Gel HTP (Bio-Rad, Richmond, CA, USA). Other column materials used were cross-linked alginate (degree of cross-linking 2.34, prepared in our laboratory). Phenyl Superose HR 5/5 and Mono Q HR 5/5 (Pharmacia Biotech, Uppsala, Sweden). 

Hofrichter, M., and Fritsche, W., Depolymerization of Low-Rank Coal by Extracellular Fungal Enzyme Systems. 3. In Vitro Depolymerization of Coal Humic Acids by a Crude Preparation of Manganese Peroxidase From the White-Rot Fungus Nematoloma Frowardii B19. Applied Microbiology and Biotechnology, 1997. 47(5) pp. 566-571. 

Effective and simple immobilization of enzymes can be obtained by the cross-linking of enzyme aggregates, so-called CLEAs [55]. In this way, essentially any enzyme, including crude preparations, can be transformed into a heterogeneous type of material, insoluble in both water and organic solvents, that is stable and recyclable with high retention of the enzyme s original activity [56], These enzyme preparations are, therefore, of special value for both bio-bio and bio-chemo cascade processes. 

Hinokiresinol formed following incubation with enzymes Crude enzyme preparation from cell culture of Asparagus officinalis (7S)-ZHR 97.2 [14]... 

The metalloprotease thermolysin, obtained from Bacillus thermoproteolyticus, a strain of B. stearothermophilus, is used as a crude preparation in an aqueous medium. The enzyme is recovered from the reaction mixture by ultrafiltration with a yield of >95%. 

Efficient kinetic resolution of chiral unsaturated secondary alcohols by irreversible enzyme-mediated acylation (with vinyl acetate as acylating agent, a crude preparation of Pseudomonas AK, and hexane as solvent) is possible, provided one relatively large and one small substituent are attached to the carbinol carbon. However, the method can be used to resolve substrates that are not amenable to asymmetric epoxidation (see examples 23, 25, 27, 29, where the double bond is either deactivated by an electron-withdrawing substituent, or is of the propargyl alcohol type). Acylation of the / -enantiomer consistently proceeds faster than that of the 5-enantiomer. An example of an allenic alcohol was also reported248. 

Already in 1946, Knox (46JBC699) presented evidence for the ability of a crude preparation of rabbit liver aldehyde oxidase to catalyze oxidation of diverse quaternary aromatic heterocyclic compounds. Later, it was demonstrated that mammalian liver contains an enzyme system that can oxidize N-methylnicotinamide 230 to both the pyridones 231 and 232 (64JBC2027 66BBA556 67JBC1271 67JBC1274). 

Because a-L-arabinofuranosidase is an extracellular enzyme, a crude preparation may be made simply by fractionation of the culture filtrate with ammonium sulfate. The enzyme can be purified from the crude enzyme-preparation by some suitable combination of ion-exchange chromatography, gel filtration, and similar techniques. Three examples of purification procedures, two from micro-organisms and one from a plant, are given here. 

Early studies revealed that the 3, 5 -cyclic phosphate diesterase is present in all mammalian tissues (38, 33, 36), being most active in cerebral cortex (36, 37). It has also been identified in extracts of liver fluke (Fasciola hepatica), the common earthworm (Lumbricus terrestris), and fly larvae (36) and it has been studied in marine organisms (38), the cellular slime mold Dictyostelium discovdeum (39, AO), and in E. coli (Al). The enzyme has been partially purified from beef heart (30), dog heart, (A8) and bovine brain (37, A3). No highly purified preparations have yet been obtained and most studies have been performed with relatively crude preparations. 

N—O-sulfation of minoxidil in the presence of adenosine-3 -phospho-5 -phosphosulfate (PAPS) (equation 24). The enzyme-synthetized product was identical to authentic N—O-sulfate with respect to chromatographic behavior and mass spectral characteristics and was split to minoxidil when treated with sulfatase183. The pH optimum for minoxidil N—O-sulfation was about 8.0. Enzyme activity in crude preparations was maintained for several months during storage at —76°C, while activity of partially purified enzyme was lost under these conditions183. 

The phage enzyme-bacterial PS substrate interaction resulted in the release of oligosaccharides. When crude preparations,... 

In spite of the fact that phenol oxidase probably plays no important role in the inactivation of pressor amines in the body, it has been reported that the injection of the enzyme into hypertensive rats led to a reduction in their blood pressure (141,143)- It is difficult to assess the value of these experiments because of the nonspecific depressor effects of crude protein preparations on blood pressure. For example, Prinzmetal et al. (126) found that their tyrosinase preparations inactivated by boiling decreased the blood pressure of hypertensive patients as well as did their enzymically active preparations. 

To prepare the biosensor mix the enzyme crude extract, the graphite powder, and fatty acid. First of all, mix the graphite powder with the... 

Thermal Stability. The temperature optimum for arctic cod pepsin is approximately 32°C see Table III) and the enzyme is unstable when incubated at temperatures above 37°C see Figure 4) in contrast to porcine pepsin which has a temperature optimum of approximately 47°C and is unstable at temperatures above 50°C see Figure 4). Accordingly, there is a difference in thermal stability of approximately 13°C for the two enzymes. Similar differences in temperature optima were observed when Greenland cod and American smelt were compared with PP see Table III). These data are consistent with previous reports for intracellular enzymes and for crude preparations of pyloric caeca enzymes from other low-temperature-adapted organisms (42). 

THC 4 d) and other cannabinoids undergo extensive biotransformation in the body, yielding scores of metabolites, several of which are themselves psychoactive. They are extremely lipid-soluble and are stored in body fat from which they are slowly released. Hepatic drug metabolising enzymes are inhibited acutely but may also be induced by chronic use of crude preparations. 

The presence of acid phosphatase in the human erythrocyte was recognized in 1934 (D4) and properties of this enzyme were studied for almost thirty years (A4, K6, Tl, T2, T4, T5) before its role in human genetics was revealed (H13). This role will be described in detail later. The properties of crude preparations of erythrocytic acid phosphatase have been previously noted in this review. At this point, we shall describe methods of purification, and the nature of the isoenzymes, particularly as they are related to the phenomenon of polymorphism. 

A crude preparation of a (1 — 4)-/3-D-galactanase from Sclerotium rolfsii72 hydrolyzed Lupinus albus D-galactan to D-galactose only this result indicates that this preparation may contain an exo-enzyme. 

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