Substrates for enzymes

For desymmetrization of diesters 3 via their hydrolysis in water, pig Hver esterase [12], o -chymotrypsin [12, 13a], and Candida antarctica Hpase (CAL-B) [14] were successfully used. However, further studies showed that respective anhydrides 5 can be used as substrates for enzyme-catalyzed desymmetrization in organic solvents [15]. The desired monoesters 4 were obtained in high yield in this way, using immobilized enzymes Novozym 435 or Chirazyme L-2 (Scheme 5.3). After the reaction, enzymes were filtered off, organic solvents were evaporated, and the crude products were crystalHzed. This was a much simpler experimental procedure in which control of the reaction progress was not necessary, and aU problems associated with extraction of products from aqueous phase and their further purification were omitted [15]. 

Certain Pyrimidine Analogs Are Substrates for Enzymes of Pyrimidine Nucleotide Biosynthesis... 

Valuable information regarding the specificity requirements of enzymes acting on carbohydrates may be expected from a discussion of fructofuranosides as substrates for enzyme action. Not only is the hydrolysis of sucrose by /3-fructofuranosidase (saccharase, invertase) one... 

Fig. 6.6 Plot of rate versus [substrate] for enzyme catalyzed reaction.

Oxygen is a substrate for enzymes located in every cell of the body and, since the corresponding participating enzymes are not of the same efficiency in different individuals, variability in the effects of oxygen lack should be expected. As Nims says "It is obvious that anoxia affects many functions and that these are not affected in the same degree from one individual to another. "21... 

Detection reagent (substrate) for enzyme-labeled antibody 2,2-azino-di(3-ethyl-benzthiazohne sulfonate-6) (ABTS) 0.3 g/L in 0.15 M sodium citrate with 0.1% H2O2 for the detection of horseradish peroxidase-labeled secondary antibody or p-nitrophenyl phosphate (pNPP) 1 g/L in 1M diethanolamine in water for the detection of an alkaline phosphatase-labeled antibody (Kirkegaard and Perry Laboratories). 

Heumann S, Eberl A, Pobeheim H et al (2006) New model substrates for enzymes hydrolysing polyethyleneterephthalate and polyamide fibres. J Biochem Biophys Methods 69 89-99... 

The only known substrate for enzymic decarboxylation is uridine 5 -(a-D-glucopyranosyluronic acid pyrophosphate). A simple reaction of this type, ieading to the a-D-xylopyranosyl ester, has been ob-... 

However, apart from absolute specificity, foreign compounds may also be substrates for enzymes involved in endogenous pathways, often with toxicological consequences. Thus, for example, with VPA (see above), fluoroacetate, and galactosamine (see chap. 7) involvement in endogenous metabolic pathways is a crucial aspect of... 

Sugar Tested Reverses Transformation Substrate for Enzyme Competitive Inhibitor... 

C. Fernandez-Sanchez and A. Costa-Garcia, 3-Indoxyl phosphate an alkaline phosphatase substrate for enzyme immunoassays with voltam-metric detection, Electroanalysis, 10 (1998) 249-255. 

Cai, S.X. et al. 2001 Design and synthesis of rhodamine 110 derivative andcaspase-3 substrate for enzyme and cell-based fluorescent assay. Bioorg. Med. Chem. Lett. 11, 39-42. 

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