Glucose-leucine system

Effect of humidity on volatile and color formation from a glucose-leucine system... 

The film reactor-ion trap mass spectrometer technique (FR-ITMS) introduced in this paper offers the potential for novel dynamic investigations of the Maillard reaction. Application of the technique to a glucose/leucine system has shown reactants, intermediates and end products to be successfully monitored in short time scales under rapidly changing reaction environments. 

K. F. Gu and T. M. S. Chang, Conversion of ammonia or urea into L-leucine, L-valine and L-isoleucine using artificial cells containing an immobilized multienzyme system and dextran-NAD+, glucose dehydrogenase for co-factor recycling, A 4/0, 11(1), 24-28 (1988). 

Proximal tubule cells in culture should have retained functional attributes such as (1) polar architecture and junctional assembly of epithelia and correct membrane distribution of enzymes and transport systems (2) vectorial transport of solutes and water, manifested by the formation of domes when cultured on solid supports [81] and the generation of transepithelial electrophysiological properties [82, 83] due to the expression of proximal tubule specific claudins 2- and 10 [84, 85] (3) cellular uptake of xenobiotics from either the apical or basolateral side, as observed in vivo and (4) expression of nephron segment-specific characteristics, i.e., distinct expression of differentiation markers, metabolic and transport properties, and hormone responsiveness. Such markers include the expression of the brush border enzymes alkaline phosphatase, leucine aminopeptidase, and y-glutamyl transferase [4, 86], In addition, proximal tubule cells should possess Na+,K+-ATPase activities, Na+-dependent glucose, and p-aminohippurate transport. Proximal tubule cells increase cAMP levels in response to parathyroid... 

Renn, P.T. and Sathe, S.K. Effects of pH, temperatme, and reactant molar ratio on L-leucine and D-glucose Maillard browning reaction in an aqueous system, J. Agric. Food Chem., 45, 3782,1997. 

Most enzymes in biological cells function as complex enzyme systems. We have prepared artilicial cells that contain multienzyme systems with cofactor recycling." This approach can convert metabolic wastes such as urea and ammonia into essential amino acids such as leucine, isoleucine, and valine, which are required by the body." We have also prepared artificial cells containing hanoglo-bin with pseudoperoxidase activity and glucose oxidase to ranove bilirubin." " ... 

In contrast to the system of Shimura et al. (1964), intact protoplasts of strain 10716 require six amino acids for production of bacitracin and, for maximal yield, glucose is needed. Disrupted protoplasts are unable to synthesize the antibiotic (Snoke, 1961). With protoplasts, the six needed amino acids are L-cysteine, L-isoleucine, L-leucine, L-histidine, L-ornithine, and L-asparagine. Neither D-orni-thine nor D-asparagine can be utihzed directly and D-phenylalanine inhibits formation of bacitracin in the absence of L-phenylalanine. A peptide factor in soybean was found to be stimulatory for synthesis of bacitracin by whole cells provided that D-phenylalanine is present in the reaction mixture (Snoke, i960, 1961). In the absence of the D-amino acid, the peptide factor is inactive. 

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