Aminotransferase secondary

Topaquinone (TPQ), the oxidized form of 2,4,5-trihydroxyphenylalanine (TOPA), is the cofactor of copper-containing amine oxidases. The following model compounds have been prepared in order to understand the catalytic function of TPQ the jV-pivaloyl derivative of 6-hydroxydopamine in aqueous acetonitrile [38] topaquinone hydantoin and a series of 2-hydroxy-5-alkyl-l,4-benzoquinones in anhydrous acetonitrile (o- as well as />-quinones) [39] 2-hydroxy-5-methy 1-1,4-benzoquinone in aqueous system [40] and 2,5-dihydroxy-1,4-benzoquinone [41]. Reaction of model compounds with 3-pyrrolines revealed why copper-quinopro-tein amine oxidases cannot oxidize a secondary N [42], The studies clearly showed that certain model compounds do not require the presence of Cu for benzylamine oxidation whereas TPQ does [38,40] the aminotransferase mechanism proceeds via the -quinone form [39] the 470 nm band can be ascribed to a 71-71 transition of TPQ in />-quinonic form with the C-4 hydroxyl ionized but hydrogen bonded to some residue [40] hydrazines attack at the C-5 carbonyl, forming an adduct in the azo form [41], Electrochemical characterization has been carried out for free TPQ [43],... 

Wink, C. and Rlartmarm, T. (1981) Properties and subcellular localisation of L-alanine aldehyde aminotransferase. Concept of an ubiquitous plant enzyme involved in secondary metabolism. Z. Naturforsch., 36c, 625-32. 

Elevations of LD activity are observed in liver disease, but these elevations are not as great as the increases in aminotransferase activity. Elevations are especially high (10 times normal) in toxic hepatitis with jaundice. Shghtly lower values are observed in viral hepatitis and in infectious mononucleosis, the latter often associated with elevations of LD-3. LD activity is normal or at most twice the upper reference limit in cirrhosis and obstructive jaundice. Serum LD-5 is often notably elevated in patients with either primary fiver disease or fiver anoxia secondary to decreased oxygen perfusion. 

Since NADPH absorbs light at 340 nm and NADP+ does not (Figure 8-3), this reaction can be followed by measurement of the change in absorbance at this wavelength with time. A similar assay (with lactate and NAD+) can be used for serum lactate dehydrogenase. The difference in absorbance is measured so readily that a number of assays make use of it directly or indirectly. In the latter case, the reaction to be measured is linked by one or more steps to a reaction in which a nicotinamide adenine dinucleotide is oxidized or reduced. Thus, in the measurement of aminotransferases (Chapter 17), one of the products of the primary reaction serves as a substrate for a secondary reaction in which NADH is required. For example, in the assay of aspartate aminotransferase,... 

The liver can be involved in CF. Biliary cirrhosis secondary to bile duct obstruction occurs in as many as 18% of patients, whereas fatty infiltration occurs in about 30% of patients in a pattern unrelated to nutritional status. Bile ducts may be obstructed by inspissated mucus, which may lead to focal or multilobar cirrhosis. Such hepatic involvement can occur at any age but is more common with advancing age and can lead to portal hypertension, esophageal varices, and hypersplenism. The most common laboratory abnormality associated with hepatic involvement is elevated serum hepatic isoenzymes (gamma-glutamyltranspeptidase, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase)." ... 

A young man mistakenly consumed tea made from an unknown amount of arnica flower and leaf. Two hours later he experienced myalgia, headache, chills, and developed hyperthermia, tachycardia, hypotension, and elevated serum levels of creatinine, aspartate aminotransferase, and alanine aminotransferase (Topliff and Grande 2000). Stomach cramping followed by death was reported in a man who had consumed 70 g of arnica tincture (Blaschek et al. 2002). Poisoning with arnica has been reported to cause death due to circulatory paralysis with secondary respiratory arrest (product and dose not specified) (Hansel et al. 1993). 

The immunochemical method was based on the precipitation of apoenzyme or holoenzyme With antibodies produced after immunization by holoenzyme. The amount of precipitated protein was higher in the case of holoenzyme than in the case of apoenzyme. These workers concluded that the binding of pyridoxal phosphate had induced changes in the secondary and tertiary structures of aspartate aminotransferase. 

The development of plant cell culture techniques has facilitated major breakthroughs in the study of the biosynthesis of plant secondary compounds (Barz and Ellis, 1981 Ellis, 1988 Flores, 1987 Hutchinson, 1986 Wink, 1987). Nonetheless, many cultures either do not produce secondary metabolites or produce an array that difiers from that found in the plant. Thus, there are still many questions to be answered. In instances where a culture fails to produce a particular chemical, it is often assumed that the enz)mies of the pathway are not formed, but, sometimes, only one enzyme is repressed or there is no product formation because of poor precursor supply, lack of storage capacity, or product degradation (Wink, 1987). The addition of exogenous precursors to the culture medium may increase product yield. For example, many plants appear to contain an L-alanine aldehyde aminotransferase that results in amine formation the supply... 

Parry RJ. Investigation of the biosynthesis of aristcromycin. Petroski RJ, McCormick SP. eds. Secondary-Metabolite Biosynthesis and Metabolism. New York Plenum Press, 1992 89-104. Lucher LA. Chen Y-M, Walker JB. Reactions catalyzed by purified L-glutamineiketo-scyllo inositol aminotransferase, an enzyme required for biosynthesis of aminocyclitol antibiotics. Antimicrob Agents Chemothet 1989 33 452-459. 

A 52-year-old man presented with jaundice and pruritus over the last 10 days after taking the boiled Equisetum Arvense Herba juice (500 ml per day) for her renal colic complaints for the last 2 weeks. Liver function tests revealed alanine aminotransferase of 818 U/L, aspartate aminotransferase of 1117 U/L, and alkaline phosphatase of 298 U/L. It was found that the patient had Child-Pugh A chronic liver disease due to hepatitis B virus. There was a temporal relationship between drinking EA juice and severe hepatitis. Liver function tests data elevated dramatically 2 weeks after starting to drink EA juice. It was suspected that the presence of the underlying chronic liver disease secondary to hepatitits B infection may have predisposed the patient to EA-induced hepatotoxicity. His liver function tests data returned completely to the pre-admission levels 8 weeks after withdrawal of the E A juice. 

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