Enzyme catalytic sites

Such structure of enzyme catalytic sites causes a stereotype of chemical mechanisms of the substrate enzymatic transformations, which is associated with the unique individuality of their adsorption sites in relation to substrate fixation . It is common knowledge that donors and acceptors of catalytic groups exchanging protons, electrons and hydride ions with the substrates have different origins in different enzymes. 

Fluorouracil is widely used in cancer chemotherapy. It is a precursor of 5-fluoro-dUMP, which is a mechanism-dependent inhibitor of thymidylate synthetase. It forms a stable methylene-bridged complex with methylene-tetrahydrofolate on the enzyme catalytic site that cannot undergo reductive cleavage. 

The hydroxylation activity of the P.450 enzyme is very important, for example, in deioxiftcation pathways. Some bioraimetic reactions have been studied in connection with this problem and, in fact, they contribuie 10 the understanding of the effects acting at the enzyme catalytic site. For example, Mimoun [54] reported on the smooth hydroylation of saturated hydrocarbons... 

The proposed biosensor has been used for nanomolar detection of various phenolic compounds (phenol, p-cresol and phenol). Above results indicates that Fe304 nanoparticles played an important role in immobilizing tyrosinase and enhancing the enzyme catalytic sites... 

If external resistance is rate controlling, a mass transfer coefficient, Ks, can be introduced. From the fluid dynamics of the reaction vessel, it is possible to estimate substrate concentration at enzyme catalytic sites according to the steady state relationship ... 

The described above properties of the tight nucleotide-binding site are of particular interest when considered together with data on its ability to catalyze hydrolysis (Fig.lb) and synthesis 73,8/ of ATP. A probable mechanism of ATP synthesis including Interchanging affinities of the enzyme catalytic site for ADP and ATP coupled with protonation--deprotonation of specific acid-base groups, has been proposed earlier 79/. 

S04 ion bound to enzyme catalytic site. Guanine base of 2, 5 CpG bound to Thr45 in B1 site with the 2, 5 CpG molecule protruding backwards away from enzyme active site toward the outside of the molecular surface. 

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