Hydrolysis hydrolases

G. Bellucci, G. Berti, M. Ferretti, E. Mastrorilli, L. Silvestri, Enantioselectivity of the Microsomal Epoxide Hydrolase Catalyzed Hydrolysis of trans-4,5-Dimethyl- 1,2-epoxycyclohexane , J. Org. Chem. 1985, 50, 1417 - 1474 G. Bellucci, M. Ferretti, A. Lippi, F. Marioni, Enantioselectivity of the Microsomal Epoxide Hydrolase Hydrolysis of ( )-cw-3-Bromo-1,2-epoxycyclohexane ,. /. Chem. Soc., Perkin Trans. 1 1988, 2715-2719. 

The stability of these compounds is maximal at pH 4 - 6, and decreases very sharply at lower and higher pH values, and the mechanism and products of the reaction differed with pH. In the neutral range, hydrolysis yielded the aromatic sulfonamide and the ester, whereas, under acid catalysis in the low pH range, the products were the AT-acyl sulfonamide and an alcohol (R OH, Fig. 11.9). Of particular interest is that the tm values for hydrolysis of the N-sulfonyl imidates in 80% human plasma were 3-150 times lower than in buffer solution at identical pH and temperature. This was taken as evidence for enzymatic hydrolysis by human plasma hydrolases. Hydrolysis under these conditions yielded the sulfonamide and the ester in quantitative amounts. 

Hydrolases (hydrolysis of amides, esters, glycosides, and lactones)... 

Hydrolases Hydrolysis reactions (transfer of functional groups to water)... 

Epoxide H AA/H Epoxide hydrolase, Hydrolysis, Phenol —OH CYP, UGT, Ipso-substitution,... 

Aldurazyme polymorphic variation of human a-L-iduronidase lysosomal hydrolase hydrolysis of terminal a-L-iduronic acid residues of dermatan sulfate and heparin sulfate No genotoxicity studies clinical trials Studies to assess mutagenic and carcinogenic potential have not been conducted No warnings or precautions regarding carcinogenic risk... 

Enzymes are placed in various major categories indicated by the first number of the EC number, namely (reaction catalysed in parentheses) (a) oxidoreductases (oxidation-reduction reactions) (b) transferases (transfer of chemical groups e.g. phosphoryl transfer) (c) hydrolases (hydrolysis or cleavage of bonds involving reaction with H20) (d) lyases (cleavage of C-C, C-O and C-N bonds and often yielding a double bond) (e) isomerases... 

III. Hydrolases Hydrolysis reaction in H20 Lipase Cellulase, Hyaluronidase Papain Polyesters, Cellulose, Glycosamino- glycans (Oligo)peptides 4, 5, 11, 12,13,14, 15,16... 

Hydrolases Hydrolysis of esters, peptides, glycerides, anhydrides, etc. lipases esterases acylases proteases phosphatases glycosidases... 

Hydrolases Hydrolysis of C-O, C-N, O-P and C-S bonds (e.g, esterases, proteases, phosphatases, deamidases)... 

Chemical reactions between biochemical compounds are enhanced by biological catalysts called enzymes, which consist mostly or entirely of globular proteins. In many cases a cofactor is needed to combine with an otherwise inactive protein to produce the catalytically active enzyme complex. The two distinct varieties of cofactors are coenzymes, which are complex organic molecules, and metal ions. Enzymes catalyze six major classes of reactions 1) Oxidoreductases (oxidation-reduction reactions), 2) Transferases (transfer of functional groups), 3) Hydrolases (hydrolysis reactions), 4) Lyases (addition to double bonds, 5) Isomerases (isomerization reactions) and 6) Ligases (formation of bonds with ATP (adenosine triphosphate) cleavage) [1]. 

Hydrolases Hydrolysis reactions Proteases hydrolyze peptide bonds in proteins. Lipases hydrolyze ester bonds in lipids. Carbohydrases hydrolyze glycosidic bonds in carbohydrates. Phosphatases hydrolyze phosphoester bonds. Nucleases hydrolyze nucleic acids. 

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