Amidohydrolases

Chemical Name L-Asparagine amidohydrolase Common Name Colapase L-Asnase Structural Formula ... 

Once inside the cell, anandamide is hydrolyzed by a specific hydrolase, anandamide amidase (AEAase) or fatty acid amidohydrolase (FAAH) (Desarnaud, 1995 Deutsch, 1993). This enzyme is membrane associated and shows significant specificity for anandamide (Desarnaud, 1995 Lang, 1999). 

Desamaud F, Cadas H, Piomelli D. Anandamide amidohydrolase activity in rat brain microsomes. J Biol Chem 1995 270 6030-6035. 

Lang W, Qin C, Lin C, Khanolkar AD, Goutopoulos A, Fan P, Abouzid K, Meng Z, Biegel D, Makriyannis A. Substrate specificity and stereoselectivity of rat brain microsomal anandamide amidohydrolase. J Med Chem 1999 42 896-902. 

A wide variety of aerobic and anaerobic microorganisms are able to express the enzyme urease (urea amidohydrolase), which catalyses the hydrolysis of urea to ammonia and carbon dioxide.27 So far,... 

Like with primary amides (see Sect. 4.2.1), bacterial amidases can be useful for the transformation of secondary amides in drug synthesis. Bacterial amidases have been extensively studied in the presence of penicillins and other [i-lactam antibiotics, for which two hydrolysis reactions are possible. One of these is carried out by enzymes known as penicillinases or /3-lactamases that open the /3-lactam ring this aspect will be discussed in Chapt. 5. The second type of hydrolysis involves cleavage of the side-chain amide bond (4.47 to 4.48) and is carried out by an enzyme called penicillinacylase (penicillin amidohydrolase, EC 3.5.1.11). Both types of hydrolysis inactivate the antibiotic [29-31],... 

K. P. Brooks, E. A. Jones, B. D. Kim, E. G. Sander, Bovine Liver Dihydropyrimidine Amidohydrolase Purification, Properties, and Characterization as a Zinc Metallo-enzyme , Arch. Biochem. Biophys. 1983, 226, 469-483. 

Very few enzymes have been characterized as lactam-forming dehydrases. One exception is carbamoylaspartic dehydrase (EC 3.5.2.3), which catalyzes the cyclization of V-carbamoylaspartic acid to dihydroorotic acid en route to pyrimidines (this enzyme is also known as dihydroorotate amidohydrolase when it catalyzes the reverse reaction). 

Goparaju SK, Ueda N, Yamaguchi H, Yamamoto S. (1998). Anandamide amidohydrolase reacting with 2-arachidonoylglycerol, another cannabinoid receptor ligand. FEBS Letters. 422(1) 69-73. 

Penicillin acylases or amidohydrolases, which cleave the amide side chain of penicillin G, have been known for almost 50 years. " As one of the first enzymes to be developed for use at scale in the pharmaceutical industry, penicillin G acylase (PGA) has often been used as a model system for academic studies from molecular biology to biochemical engineering. Despite extensive screening, however, for decades there was no equivalent enzyme to generate 7-ACA by cleaving the polar D-a-aminoadipoyl side chain from cephalosporin C. 

The crystal structure of FB188 HDAH (histone deacetylase-like amidohydrolase from Bordetella/Alcaligenes strain FB188), a baderial class II HDAC homolog. 

Leipe, D.D. and Landsman, D. (1997) Histone deacetylases, acetoin utilization proteins and acetylpolyamine amidohydrolases are members of an ancient protein superfamily. Nucleic Acids Research, 25 (18), 3693-3697. 

The equilibrium of reversible histone lysine acetylation is maintained by histone deacetylases (H D ACs) on one hand and histone acetyltransferases on the other hand. Human histone deacetylases can be separated into four classes [15]. HDACs of class I, II and IV are zinc-dependent amidohydrolases, whereas class III HDACs, also referred to as sirtuins, have a mechanism that is dependent on NAD [16]. As histone deacetylases have been widely studied, it is not surprising that there are also a large number of assays existing that have helped to characterize modulators of these enzymes and subsequently the enzymes themselves. 

Hildmann, C., Ninkovic, M., Dietrich, R., Wegener, D., Riester, D., Zimmermann, T, Birch, O.M., Bernegger, C., Loidl, P. and Schwienhorst, A. (2004) A new amidohydrolase from Bordetella or Alcaligenes strain FB188 with similarities to histone deacetylases. Journal of Bacteriology, 186, 2328-2339. 

This enzyme [EC 3.2.2.11], also referred to as 1-aspar-tamido-/3-A-acetylglucosamine amidohydrolase, catalyzes the hydrolysis of l-jS-aspartyl-iV-acetylglucosami-nylamine to yield iV-acetylglucosamine and asparagine. 

This enzyme [EC 3.5.1.10], also known as formyltetrahydrofolate amidohydrolase and formyl-FH4 hydrolase, catalyzes the hydrolysis of 10-formyltetrahydrofolate to yield formate and tetrahydrofolate. 

L-asparaginase II precursor (L-asparagine amidohydrolase II) (L-asnase II) (Colaspase) ... 

Penicillin and related antibiotics are inactivated by P-lactamases (Box 20-G), some of which resemble serine proteases in forming acyl enzymes with active site serine side chains.656 657 Others are zinc metallogen-zymes.658/659 Amidohydrolases such as asparaginase and glutaminase,660/661 deacetylases,662 and many other hydrolases can also be described as acyltransferases. 

The first enzyme that was demonstrated to contain nickel was urease (urea amidohydrolase) from jack bean. It catalyzes the hydrolysis of urea to ammonia and carbon dioxide. The protein has a multimeric structure with a relative molecular mass of 590,000 Da. Analysis indicated 12 nickel atoms/mol. Binding studies with the inhibitors indicated an equivalent weight per active site of 105,000, corresponding to 2 nickel atoms/active site. During removal of the metal by treatment with EDTA at pH 3.7, the optical absorption and enzymatic activity correlated with nickel content. This, combined with the sensitivity of the enzyme to the chelating agents acetohydroxamic acid and phos-phoramidate, indicates that nickel is essential to the activity of the enzyme (1). 

The title retains the trivial name for enzymes with the systematic name of urea amidohydrolase and the Enzyme Commission code number of EC 3.5.1.5. Ureases are hydrolases acting on C-N bonds (nonpeptide) in linear amides and thus belong to a group that includes glutaminase, form-amidase, and formyltetrahydrofolate deformylase. The title is plural to emphasize that urease activity may be exhibited by several protein species. Urease, singular, has come to mean by common usage, that particular enzymic protein first crystallized by Sumner from jack bean... 

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