Transferase activity

Aminohexose Nucleosides. The 4-aminohexose nucleosides (128—140) are Hsted in Table 7 (1—4,240—242). A biosynthetic relationship between the 4-aminohexose peptidyl nucleoside antibiotics and the pentopyranines has been proposed (1). The 4-aminohexose pyrimidine nucleoside antibiotics block peptidyl transferase activity and inhibit transfer of amino acids from aminoacyl-tRNA to polypeptides. Hikizimycin, gougerotin, amicetin, and blasticidin S bind to the peptidyl transferase center at overlapping sites (243). 

Application of the desired biotransformation to give a practical and economical process required high molar conversion yields, high amino transferase activities, highly effident product recovery and an inexpensive source of phenylpyruvic add. With genetic and/or biochemical manipulation considerable progress can be made towards meeting some of these requirements. 

Gamma-glutamyl-transferase activity was determined according to "Monotest 10 y-GT neu" from Boehringer-Mannheim. 

Polidoro G, Dillio C, Arduini A, et al. 1982. Glutathione peroxidase and glutathione S-transferase activities in human fetal tissues. Inability of acidic forms of glutathione S-transferase to catalyze the reduction of organic hydroperoxides. Biochem Int 4 637-645. 

Another common liver disease, alcoholic liver damage produced by moderate to heavy alcoholic intake, is also reflected by an elevation of the serum GOT and GPT activities. The serim glutamyl transferase activity is reported to be a sensitive index of alcoholic intake and can serve to monitor persons on alcoholic withdrawal programs (60). The LD-5 isoenzyme arises mainly from liver tissue, but has a short half-life (61), which is about 1/5 and 1/2 of the half life of the transaminases, GPT and GOT respectively. Some authors consider that a normal LD-5 isoenzyme activity in a jaundiced patient is sufficient evidence to exclude primary liver disease and that obstruction is probably responsible for the jaundice (62). In hemolytic jaundice the LDH-1 and 2 isoenzymes are elevated. 

Polyphenols and flavanoids in rat liver microsomal fractions have been demonstrated to inhibit glucuronidation of estrone and estradiol in vitro (Zhu et al, 1998). In addition, flavonoids have also been found to induce phase I and II enzymes in rats including UDP-glucuronosyl transferase (Seiss et al, 1996). However, the effects of phytoestrogens have not been evaluated for either their inhibition or induction of glucuronosyl transferase activity. 

SPARNINS V L, BARANY G, WATTENBERG Lw. (1988) Effects of organosulfur compounds from garlic and onions on benzo[a]pyrene-induced neoplasia and glutathione S-transferase activity in the mouse. Carcinogenesis. 9 131-4. 

Lam, L. K. T., Sparnins, V. L., Wattenberg, L. W., Isolation and identification of kahweol palmitate and cafestol palmitate as active constituents of green coffee beans that enhance glutathione-S transferase activity in the mouse, Cancer Res., 42, 1193, 1982. (CA96 198149d)... 

As detailed structural information is obtained from a greater diversity of parasitic nematodes it is expected that the occurrence of stage-specific carbohydrate antigens, and therefore stage-specific glycosyl transferase activities, will be identified as a common characteristic. 

The ribosome is a ribozyme this is how Cech (2000) commented on the report by Nissen et al. (2000) in Science on the successful proof of ribozyme action in the formation of the peptide bond at the ribosome. It has been known for more than 30 years that in the living cell, the peptidyl transferase activity of the ribosome is responsible for the formation of the peptide bond. This process, which takes place at the large ribosome subunit, is the most important reaction of protein biosynthesis. The determination of the molecular mechanism required more than 20 years of intensive work in several research laboratories. The key components in the ribosomes of all life forms on Earth are almost the same. It thus seems justified to assume that protein synthesis in a (still unknown) common ancestor of all living systems was catalysed by a similarly structured unit. For example, in the case of the bacterium E. coli, the two subunits which form the ribosome consist of 3 rRNA strands and 57 polypeptides. Until the beginning of the 1980s it was considered certain that the formation of the peptide bond at the ribozyme could only be carried out by ri-bosomal proteins. However, doubts were expressed soon after the discovery of the ribozymes, and the possibility of the participation of ribozymes in peptide formation was discussed. 

Lee EJD, Kalow W. Thiopurine S-methyl-transferase activity in a Chinese population. Clin Pharmacol Ther 1993 54 28-33. 

For protection of domestic cattle, feeds should contain <0.05 mg diflubenzuron/kg FW. Cottonseed may be added to cattle diets provided that diflubenzuron concentrations in the seed do not exceed 0.2 mg/kg FW and that cottonseed composes <17% of the total diet bulk (Gartrell 1981). Diflubenzuron causes biochemical upset, as judged by lowered testosterone levels in chickens and rats (USEPA 1979), altered glutathione 5-transferase activity in mouse liver (which adversely affects the ability to detoxify foreign substances by way of conjugation Young et al. 1986), and disrupted hydroxylamine activity in human infants (USEPA 1979). Additional research seems needed on biochemical alterations induced by diflubenzuron. No diflubenzuron criteria are currently recommended for protection of avian and mammalian wildlife. All data available suggest that wildlife species are about as tolerant to diflubenzuron as are domestic poultry and livestock however, the wildlife database seems inadequate for practicable criteria formulation. 

Oral dose of 1000, 2500, or 4000 mg/kg BW maintained at 22°C or minus 5°C for 10 h after dosing No deaths. Mild intoxication and elevated plasma alanine amino-transferase activity holding temperature did not affect toxicity 8... 

Sakanashi, M., Matsuzaki, T., Aniya, Y., Nitroglycerin relaxes coronary artery of the pig with no change in glutathione content or glutathione-S-transferase activity. Br. J. Pharmacol. 103 (1991), p. 1905-1908... 

The extent to which the level of galactose-l-phosphate uridyl transferase activity in erythrocytes reflects the level in the liver is unknown except for a bandful of cases. This problem is worth further investigation with particular reference to these 2 groups of heterozygotes, those showing unusual galactose intolerance and those with very low enzymatic activity. 

Perry, H.M., Tane, M. and Camody, S. (1970). Relationship of acetyl transferase activity to antinuclear antibodies and toxic symptoms in hypertensive patients treated with hydralazine. J. Lab. Clin. Med. 76 114-125. 

Wadleigh RW, Yu SJ (1987) Glutathione transferase activity of fall armyworm larvae toward alpha-, beta-unsaturated carbonyl allelochemicals and its induction by allelochemicals. Insect Biochem 17 759-764... 

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