Liver enzymes, chromatography

Hepatitis was diagnosed in a 31-year-old pregnant woman who had been taking shou wu pian (dose unspecified), a proprietary product made from fo-ti tuber, for several weeks prior to the hepatitis. Elevated plasma levels of liver enzymes were observed, and viral hepatitis was ruled out. Liver enzyme levels returned to normal 3 weeks after cessation of the product. The identity of the product was confirmed by thin-layer chromatography, and two anthraquinones, emodin and physcion, were identified. The patient described a case of hepatitis that she had 2 years prior after taking a liquid extract prepared from fo-ti (But et al. 1996). 

Huang Z-P, Chen X-H, Wijsbeek J, Franke J-P, de Zeeuw RA. 1996. An enzymic digestion and solid-phase extraction procedure for the screening for acidic, neutral, and basic drugs in liver using gas chromatography for analysis. J Anal Toxicol 20 248. 

C. Nomeir, A. A. Validation of higher-throughput high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry assays to conduct cytochrome P450s CYP2D6 and CYP3A4 enzyme inhibition studies in human liver microsomes. Rapid Commun Mass Spectrom 2000, 14, 207-214. 

Sialyltransferases can be solubilized from their subcellular site by using detergents, and be purified by affinity chromatography on, for example, CDP-6-aminohexanol-agarose,267 as already described. Solubilization of frog- and rat-liver sialyltransferases by means of Triton X-100 has been described.27 Soluble sialyltransferase occurs in colostrum, and is also present in small quantities in normal blood-serum. From the latter source, the enzyme was purified 300-fold by poly (acrylamide) gel-electrophoresis.2 ... 

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. 

Brightwell and Tappel (90) purified rat liver acid phosphatase from a lysosomal fraction by DEAE and CM-cellulose chromatography. Table XX (90) shows the specificity of the lysosomal 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... 

The enzyme DGAT has not been purified to date, probably because it is a hydrophobic and integral membrane protein. Therefore, DGAT activity was measured using rat liver microsomes as an enzyme source and radiolabeled palmitate as a substrate by the method of Mayorek and Bar-Tana [52] with some modifications [53], The reaction mixture contains microsomal protein, BSA, [14C]palmi-toyl-CoA, MgCl2, diisopropyl fluorophosphate, 1,2-dioleoyl-vw-glyccrol, and a test sample in a total volume of 0.2 ml. After a 15-min incubation at 23°C, lipids are extracted and separated by thin-layer chromatography (TLC). The distribution of radioactivity on TLC is analyzed with a radioscanner to determine the amount of [14C]TG. 

Acetyl-CoA arylamine N-acetyltransferase was purified from pigeon liver by using steps involving protamine sulfate, ammonium sulfate fractionation, and affinity chromatography on immobilized amethopterin. Figure 9.20 shows a representative chromatogram. In another study, Thomas et al. (1990) used tryptamine as the substrate. In addition, whereas the study by Manneus et al. (1990) appeared to require pure enzyme, Thomas s study did not. 

The enzyme preparation used was obtained by chromatography of the high speed supernate of a phosphate extract of rat liver on a glutathione-agarose affinity column. 

The enzyme preparation used was purified to apparent homogeneity from human liver by affinity chromatography on agarose-e-aminocaproylfucos-amine resin. 

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