Aminotransferases strain

Figure 2-10 Ramachandran plot for cytosolic aspartate aminotransferase. The angles and / were determined experimentally from X-ray diffraction data at 0.16 nm resolution and model building. The majority of conformations are those of a helices or of P structure. Glycine residues are indicated by filled circles, while all other residues are denoted by an "x". One of these (green) lies quite far from an allowed area and must give rise to localized strain.104b Extreme lower limit "allowed" regions by the hard-sphere criteria are shown in outline. From coordinates of Arthur Amone et al. (unpublished).106...

No significant difference in levels of serum glutamic-pyruvate transaminase (SGPT, also known as alanine aminotransferase [ALAT]) was observed in six mice (strain not specified) treated once by gavage with 22.5 mg/kg/day 2,4-DNP (Robert 1986). Two dogs repeatedly fed capsules containing... 

Two observations indicate that aspartate is formed primarily by a transamination reaction, probably from glutamate, rather than by a direct amination with NH4 in A. cylindrica. First, N-label in aspartate was reduced more than 90% by the presence of aminooxy acetate, while labeling of glutamate and glutamine was not reduced (IS). Second, [ N]aspartate was not detected when glutamate formation was inhibited either directly, by azaserine, or indirectly, when glutamine s)mthesis was inhibited by methionine sulfoximine (13). Moreover, activity of a glutamate-aspartate aminotransferase reaction has been detected in vitro in two strains of A. cylindrica (1,26). 

The potential of biotransformations with genetically modified microorganisms can be illustrated by the following example, where the chain of added-value to amino acid products is also recognisable The Mercian Company (Japan) uses a recombinant E. coli strain to prepare (S)-piperidine-2-car-boxylic acid from (L)-lysine. In this strain, the (L)-lysine-permease transport system is overexpressed, so that in this pathway lysine is produced efficiently in the cells. The bacteria possess additionally a (L)-lysine-aminotransferase from Flavobacterium lutescens, which brings about the deamination of lysine. The thus generated aldehyde is in equilibrium with its intramolecular imine, which, in presence of the E. co/i-specific pyrroline-5-carboxylate reductase, is reduced with NADPH to (S)-piperidine-2-carboxylic acid. The turnover... 

Cabirol, F.L, Gohel, A., CoBier, S.J., liang, J., Mock, M., Mimdorff, E., Novick, S., limanto, J., Smith, D., and Beutner, G. (2012) Biosynthesis of (lR,2R)-2-(3,4-dimethoxyphenethoxy)cyclohexanamine using genetically modified to-aminotransferases for Arthrobacter strain KNK168. PCTInt. Appl, WO 2012024104 A2 20120223. 

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