Alcohol dehydrogenase , activity

Fig. 30. Variation of alcohol dehydrogenase activity with number of passes through various pumps [42]...

Roth R, Boudet AM, Pont-Lezica R. Lignification and cinnamyl alcohol dehydrogenase activity in developing stems of tomato and popular a spatial and kinetic study through tissue printing. J Exp Bot 1997 48 247-254. 

J. Boehnlein, A. Sakr, J. L. Lichtin, R. L. Bronaugh, Characterization of Esterase and Alcohol Dehydrogenase Activity in Skin. Metabolism of Retinyl Palmitate to Retinol (Vitamin A) During Percutaneous Absorption , Pharm. Res. 1994, 11, 1155-1159. 

The rate of ethanol degradation in the liver is limited by alcohol dehydrogenase activity. The amount of NAD" available is the limiting factor. As the maximum degradation rate is already reached at low concentrations of ethanol, the ethanol level therefore declines at a constant rate (zero-order kinetics). The calorific value of ethanol is 29.4 kj g Alcoholic drinks—particularly in alcoholics—can therefore represent a substantial proportion of dietary energy intake. 

As with adults, the primary organ responsible for drug metabolism in children is the liver. Although the cytochrome P450 system is fully developed at birth, it functions more slowly than in adults. Phase I oxidation reactions and demethylation enzyme systems are significantly reduced at birth. However, the reductive enzyme systems approach adult levels and the methylation pathways are enhanced at birth. This often contributes to the production of different metabolites in newborns from those in adults. For example, newborns metabolize approximately 30% of theophylline to caffeine rather than to uric acid derivatives, as occurs in adults. While most phase I enzymes have reached adult levels by 6 months of age, alcohol dehydrogenase activity appears around 2 months of age and approaches adult levels only by age 5 years. 

Lactobacillus brevis whole-cell biotransformation When the reduction of diketo ester la was performed with whole cells of Lactobacillus brevis or L. kefir, formation of the 3,5-dihydroxy ester (3R,5S)-5a was observed [10, 22]. This was surprising since it is known that the prevailing alcohol dehydrogenase in I. brevis is the one described as LBADH [23] and since, moreover, this enzyme does not reduce P-keto 5-hydroxy ester 2a to the corresponding dihydroxy ester (Scheme 2.2.7.6). Under the conditions tested, further alcohol dehydrogenase activity is clearly present in I. brevis and I. kefir. Pfruender et al. optimized the production of L. kefir cells and used this biocatalyst for the one-pot synthesis of dihydroxy ester syn-(3R,5S)-5a using diketo ester la as starting material [24]. 

The mechanisms that underlie ethanol s teratogenic effects are unknown. Ethanol rapidly crosses the placenta and reaches concentrations in the fetus that are similar to those in maternal blood. The fetal liver has little or no alcohol dehydrogenase activity, so the fetus must rely on maternal and placental enzymes for elimination of alcohol. 

Marshall, V. M. and Cole, W. M. 1983. Threonine aldolase and alcohol dehydrogenase activities in Lactobacillus bulgaricus and Lactobacillus acidophilus and their contribution to flavour production in fermented foods. J. Dairy Res. 50, 375-379. 

Mitchell, H.J., Hall, J.L., and Barber, M S., 1994, Elicitor-induced cinnamyl alcohol dehydrogenase activity in lignifying wheat (Triticum aestivum L.) leaves, Plant Physiol. 104 551-556. 

Blandino, A., Caro, I., and Cantero, D. (1997). Comparative study of alcohol dehydrogenase activity in flor yeast extracts. Biotechnol. Lett. 19, 651-654. 

Chkaiban, L., Botondi, R., Bellincontro, A., De Santis, D., Kefalas, P., and Mencarelli, F. (2007). Influence of postharvest water stress on lipoxygenase and alcohol dehydrogenase activities, and on the composition of some volatile compounds of Gewiirtztraminer grapes dehydrated under controlled and uncontrolled thermohygrometric conditions. Aust. J. Grape Wine Res. 13,142-149. 

Seitz HK, Egerer G, Simanowski UA, Waldherr R, Eckey R, Agarwal DP et al. Human gastric alcohol dehydrogenase activity Effect of age, sex, and alcoholism. Gut 1993 34 1433-7. 

Frezza, M., di Padova, C., Pozzato, G., Terpin, M., Baraona, E., Lieber, C.S. High blood alcohol levels in women. The role of decreased gastric alcohol dehydrogenase activity and first-pass metabolism. New Engl. J. Med. 1990 322 95-99... 

C, Arce, L., Waldherr, R., Stickel, F., Russell, R.M., Aderjan, R., Klee, F., Seitz, H.K. Helicobacter pylori infection decreases gastric alcohol dehydrogenase activity and first-pass metabolism of ethanol in man. Digestion 1998 59 314- 320... 

CabaUeria J, Baraona E, Rodamilans M, Lieber CS. Effects of cimetidine on gastric alcohol dehydrogenase activity and blood ethanol levels.. Gastroenterology 1989 96(2 Pt 1) 388-92. 

Some effects on absorption can be subtle, such as the greater absorption of alcohol in women due to their reduced gastric mucosal and liver alcohol dehydrogenase activity compared to men. This results in higher circulating levels of alcohol, in spite of body weight corrections (Frezza et al., 1990), with obvious implications. Odansetron, on the other hand, is more slowly metabolized by women and thus may be more effective. 

The alcohol dehydrogenase activity was about twice as high in juice from anaerobic-treated fruit, but the levels of malic enzyme (ME), malate dehydrogenase (MDH), and pyruvate decarboxylase (PDC) were not greatly affected by the treatment. 

The inhibition of alcohol dehydrogenase activity by OP has been reversible under experimental conditions employed thus far. With OP as the inhibitor, Eq, 2 apparently prevails. In view of the high association constants of the [Zn(OP) ]++ complexes (Kolthoff, Leussing, and Lee, 1951), the corresponding constants of the [(ADH)ZnJ complex must be very high indeed. 

Yang, R and Russell, A. 1., Optimization of baker s yeast alcohol dehydrogenase activity in an organic solvent, BiotechnoL Prog., 9, 234—241, 1993. 

Yang, E. and Russell, A. J., The role of hydration in enzyme activity and stability. 2. Alcohol dehydrogenase activity and stability in a continuous gas phase reactor, Biotechnol. Bioeng., 49, 709-716, 1996. 

Agricultural biotechnology research guidelines, 422-429 Agricultural Research Service, 230 Alcohol dehydrogenase activity, male-limited, 142... 

---