Amino acid oxidation status

There is no question that dehydration can significantly alter exercise performance and ultimately lead to more severe medical disorders such as heat stress and heat stroke. Hydration status is also a determinant of amino acid oxidation, with cellular dehydration inducing an increase in leucine oxidation and cellular hyperhydration showing the opposite in resting yoimg men.Although dehydration dining... 

The cyde is central to the oxidation of any fuel that yields acetyl CoA, induding glucose, fritty acids, ketone bodies, ketogenic amino acids, and alcohol There is no hormonal control of the cyde, as activity is necessary irrespective of the fed or fasting state. Control is exerted by the energy status of the cell. 

Nutritional and nutritional status markedly influence xenobiotic metabolism in laboratory animals. Microsomes were prepared from the livers of rats which had been fed chow or modified AIN-76 diets with or without oxidized or unoxidized sulfur amino acids for 7 days. The pattern of benzo(a)pyrene (BaP) metabolites formed by each microsomal preparation in the presence of a NADPH-generating system was determined using high performance liquid chromatography (HPLC). The results indicate that oxidized sulfur amino acids induce different forms of cytochromes P-450 in rat liver Which are reflected by different BaP metabolic profiles. 

A variety of phytoplankton are known to possess cell surface oxidases (Palenik and Morel, 1990a,b) and extracellular oxidation of amino acids has been shown to occur in nature (Pantoja and Lee, 1994 Mulholland et al., 1998, 2002a). Direct uptake of amino acid-derived N from this process represented up to 4% of the observed NFI4+ uptake in a mid-Adantic estuary (Mulholland et al., 2003). Recently, a cell surface protein expressed under N-limitation was identified as a deaminase suggesting that these enzymes are regulated by cellular N status as for other pathways of N uptake and metabolism (Palenik and Koke, 1995). Failure to account for alternative pathways for mobilization of DON might result in underestimates of its utilization in nature. 

This pathway to anhalonidine has now been shown to be essentially correct by in vivo experiments.33 Administration of [l,9-14C]peyoruvic acid (44) to peyote cacti resulted in an efficient and specific incorporation of activity into the alkaloid, without a change in isotopic ratio. The status of the amino-acid as a true intermediate was confirmed by chemical analysis to show that it is present in the peyote cactus. Further support for Scheme 5 was provided by incubation of [9-14C]peyoruvic acid (44) with fresh peyote slices. Carbon dioxide was evolved and on work-up the decarboxylation product was found to be the imine (45), specifically labelled with 14C at C(9). The production of the imine rather than the tetrahydroisoquinoline (43) suggests that the decarboxylation may be an oxidative process and this interesting reaction deserves further investigation. 

Experience has shown that the resolution by RPC methods of very closely related proteins, such as deamido forms, methionine 5-oxide, or N-terminal methionyl variants, is best achieved if mobile phase conditions can be chosen whereby the native structures of the proteins are preserved in the RPC system. The choice of these conditions frequently dictates that higher pH conditions, i.e., pH 4.5-7.5, are selected in these cases. To address these requirements and to take advantage of the ionization status of the amino acid side chains, a very large number of different ion-pairing reagents (including those already indicated... 

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