Acetone powders

Bromelain (anti-inflammatory Ananase from pineapple) [37189-34-7] Mr 33 000, [EC 3.4.33.4]. This protease has been purified via the acetone powder, G-75 Sephadex gel filtration and Bio-Rex 70 ion-exchange chromatography and has Aj 20.1 at 280nm. The protease from pineapple hydrolyses benzoyl glycine ethyl ester with a Km (app) of 210mM and kcat of 0.36 sec. [Murachi Methods Enzymol 19 273 1970 Balls et al. nd Eng Chem 33 950 1941.]... 

The live fireflies are dried over calcium chloride in a vacuum desiccator, and then their lanterns are separated by hand. An acetone powder prepared from the dried lanterns is extracted with boiling water. The cooled aqueous extract is extracted with ethyl acetate at pH 3.0, and the ethyl acetate layer is concentrated under reduced pressure. The concentrated luciferin is adsorbed on a column of Celite-Fuller s earth mixture. The column is washed with water-saturated ethyl acetate, and eluted with alkaline water at pH 8.0-8.5. The aqueous eluate of luciferin is adjusted to pH 3.0 with HCl and luciferin is... 

Purification of Pholas luciferase (Michelson, 1978). Acetone powder of the light organs is extracted with 10 mM Tris-HCl buffer, pH 7.5, and the luciferase extracted is chromatographed on a column of DEAE Sephadex A-50 (elution by NaCl gradient from 0.1 M to 0.6 M). Two peaks of proteins are eluted, first luciferase, followed by a stable complex of luciferase and inactivated pholasin. The fractions of each peak are combined, and centrifuged in 40% cesium chloride... 

Extraction and purification of Diplocardia luciferase (Bellisario et al., 1972). About 50 specimens of Diplocardia longa (widespread in southern Georgia about 30 cm in length) were electrically stimulated in 250 ml of 0.1 M EDTA at 4°C to exude coelomic fluid. The suspension of coelomic cells obtained was centrifuged at 480 g for 5 min. The pellets from 200 worms were combined and an acetone powder was prepared. The acetone powder obtained (about 10 g) was stable at -80°C for at least one year. 

Acetone powder (1.5 g) was extracted 4 times with 0.1 M sodium borate buffer (pH 7.6) at 4°C, homogenizing each time with a glass grinder equipped with a Teflon pestle. The first extraction was carried out with 80 ml of the buffer, followed by 3 times with 70 ml each of the buffer. Each homogenate was centrifuged at 16,000 g for 5 min. All supernatants were combined. 

Davenport et al. (1952) were unsuccessful in their attempts to restore the luminescence of the filtered aqueous extract of Luminodesmus. Hastings and Davenport (1957) saw a weak luminescence in their filtered aqueous extracts made from the acetone powder of the millipedes. They found that the luminescence is dependent on pH, with an optimum at about pH 8.9, and that the light intensity could be increased by 10-30% by adding ATP. Hastings and Davenport also measured the luminescence spectrum of live animals, finding an emission peak at 495 nm. 

An acetone powder of P. homomalla was subsequently used to generate allene oxide 64 from exogenous 8P-HPETE [91]. This highly unstable compound (t1/2 = ca. 15 s at 0 °C, pH 7.4) was obtained by performing the biosynthesis at low temperature (0 °C) for 2 min in a vortexed emulsion of pH 6 buffer and pentane. Under these conditions, the allene oxide partitioned into the pentane where it was relatively protected from hydrolysis. HPLC analysis of the... 

Additional hypotheses concerning prostaglandin biosynthesis in P. homomalla resulted from isolation of 11R-HETE (76) from the polar lipid fraction [95]. Apparently, 11R-HETE (76) is also a minor product of incubations of arachidonic acid with acetone powder preparations of P. homomalla [95], In this alternate hypothesis (Scheme 8), an 11-hydroxy or 11-hydroperoxy-8,9-allene oxide intermediate is formed from a sequence of oxidations at C8 and Cll. Opening of the allene oxide to a transient C8 earboeation induces eycli-zation with a consequent addition of water to C15. This proposed pathway leads initially to formation of PGE2 (16 or 38), which following acetylation, elimination of acetic acid from Cl 1-12, and esterification, forms the observed major natural product in the coral, 15-acetoxy methyl PGA2 (36 or 54). Notably, if... 

PGA2 biosynthesis could be accomplished with this acetone powder preparation, this hypothesis could readily be tested, since it predicts that the C15 hydroxyl would derive from water rather than molecular oxygen. However, no further experimental substantiation of this intriguing hypothesis has appeared. 

Enzyme Commercial acetylcholinesterase preparation - electrical organ acetone powder (extract) from electric eel (Electrophorus electricus) (Sigma, E2384) was used. 

The preparation of AChE-biotest includes the following stages, (i). the preparation of homogenate from tissue with high cholinesterase activity (electrical organ acetone powder). Homogenate are preparated in phosphate... 

Isolation yield, using 60 mg (1.9 U) of home-made acetone powder of P. t/u/c/skernel meal per millilitre of reaction mixture. 

Structure and Crystallinity. The mechanical-optical properties of polycarbonates are those common to amorphous polymers, The polymer may be crystallized lo some degree by prolonged heating at elevated temperature (8 d at 180°C), or by immersion in acetone. Powdered amorphous powder appears to dissolve partially in acetone, initially becoming sticky, then hardening and becoming much less soluble as it crystallizes, Enhanced crystallization of polycarbonate can also be caused by the presence of sodium phenoxide end groups. 

M. phlei, and several strains of M. tuberculosis (28-30) contain a true asparaginase, as do extracts of Bacillus coagulans and Bacillus stearo-thermophilus (31). Brucella abortus contains two asparaginases, one specific for L-asparagine and the other for the opposite enantiomorph (32). An asparaginase is also present in Pseudomonas fluorescens (33). Also, Tsuji, in 1957, had reported the presence of asparaginase in extracts of acetone powders of E. coli, Staphylococcus, M. avium, and Aspergillus oryzae (34). 

An apparently different 5 -nucleotidase has been partially purified (50-fold) from acetone powder preparations of chicken liver (82) 5 -IMP and 5 -GMP are hydrolyzed by this preparation more rapidly than other 5 -nucleotides 5 -AMP, 5 -UMP, and 5 -CMP are hydro-... 

Center and Behai (49) have resolved 5 -nucleotidase from calf intestinal mucosa into three fractions using DEAE-cellulose chromatography. One of these was obtained free of nonspecific phosphatase. It had a pH optimum of 6-6.5, Mn2+, Mg2+, and Co2+ (1-10 mill) all enhanced activity and complete inactivation was produced with 1 mM EDTA. This enzyme hydrolyzes all 5 -ribonucleotides at similar rates and hydrolyzes 5 -deoxribonucleotides more slowly. These properties indicate that it is strikingly similar to the one obtained from acetone powder preparations of chicken and rat liver (32, 33) and from soluble supernatants of rat liver (36). The other two activities (which were not fully characterized) (49) could possibly have originated from particulate material or membranes because the authors employed deoxycholate in the early phase of purification. 

The enzyme in the myocardium has recently attracted attention because of the possibility that adenosine is a physiological regulator of coronary blood flow (67) (adenosine is a potent coronary dilator). Most of the 5 -nucleotidase activity in rat heart is membrane bound, and a partially purified preparation has been obtained by extracting acetone powder preparations with deoxycholate (68). All 5 -nucleotides are hydrolyzed. The enzyme is strongly inhibited competitively by ATP (Ki 1.8 fxM). Whether this provides a regulatory mechanism for adenosine formation in the heart is not known. 

It appears certain that there is more than one 5 -nucleotidase present in most mammalian tissues. This is best established for liver. In other cases it has not been possible to determine the exact intracellular origin because of the nonselective extraction procedures used. However, those enzymes isolated from acetone powder preparations of chicken liver and rat liver appear to have properties essentially identical to the enzyme present in 100,000 X ff supernatant fraction of rat liver and therefore may be cytoplasmic in origin. This could also be the case for the intestinal mucosa enzyme. 

Since the discovery and partial purification of FDPase by Gomori (2), a number of purification procedures have been described (4, 22, 24-27). Among these, the most widely employed are based on the procedure of Pontremoli et al. (22), using acetone powders from freshly collected rabbit livers. The steps include precipitation of inactive protein at pH 4.5, fractionation with ammonium sulfate, heating to 50°, and chromatography on carboxymethyl cellulose columns, from which the enzyme... 

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