Acid hydrolases synthesis

The induction of specific acid hydrolase synthesis is the result of (1) a... 

A. Natube and Pathogenesis of Stimulation of Acid Hydrolase Synthesis... 

Dysynchronovs Lysosome-Vacdolar Acid Hydrolase Synthesis Induced by Various Stjmuu... 

Hydrolases carry out important degradative reactions in the body. During digestion, lipases hydrolyze lipids and proteases convert protein to amino acids. Hydrolases cleave large molecules into fragments used for synthesis, the excretion of waste materials, or as sources of carbon for the production of energy. In these reactions, many biopolymers are converted to monomers. Some hydrolases release energy as they act. 

I-cell disease is, then, a disorder of targeting, which appears to arise during the synthesis of the acid hydrolases. The detailed enzymology of the primary error is not yet fully understood. 

Amino acids must be provided for de novo hydrolase synthesis Undisputed... 

The synthesis of enzymes is a continuous process in every living celL Synthesis of acid hydrolases in mammalian cells requires not only the possession of the appropriate gene but also the presence of a specific substrate or a substance closely related to it to act as specific enzyme inducer. The phenomenon is termed enzyme induction. The opposite phenomenon exists and is referred to as enzyme repression. Acid hydrolases in a cell will depend, therefore, upon the presence of the particular gene... 

It is reasonable that the process of vesiculation occurs at an equilibrium rate, constant for each cell species and modified by the metabolic demands of the cells. We have suggested (Verity and Brown, 1968b), from maturation studies of cerebral lysosomal enzymes, that for a given rate of vesiculation, the enzyme complement of the primary lysosome is directly proportional to the individual rates of synthesis of the component enzymes. Such a hypothesis would account for the heterogeneity in acid hydrolase reaction to injury, the difference in maturation profiles of individual acid hydrolases, and the dysynchrony of acid hydrolase induction. Also suggested is a direct feedback mechanism whereby a stimulation of vesiculation may in turn induce increased enzyme synthesis, possibly through changes in membrane phospholipid metabolism. 

Asano et al. have developed an approach for the synthesis of D-amino acids through DKR using a two-enzyme system [55]. They had previously reported the discovery of new D-stereospecific hydrolases that can be applied to KR of racemic amino acid amides to yield D-amino acids. Combination of a D-stereospedfic hydrolase with an amino acid amide racemase allows performing DKR of i-amino acid amides yielding enantiomerically pure D-amino acids in excellent yields (Figure 4.29). 

Thioesters play a paramount biochemical role in the metabolism of fatty acids and lipids. Indeed, fatty acyl-coenzyme A thioesters are pivotal in fatty acid anabolism and catabolism, in protein acylation, and in the synthesis of triacylglycerols, phospholipids and cholesterol esters [145], It is in these reactions that the peculiar reactivity of thioesters is of such significance. Many hydrolases, and mainly mitochondrial thiolester hydrolases (EC 3.1.2), are able to cleave thioesters. In addition, cholinesterases and carboxylesterases show some activity, but this is not a constant property of these enzymes since, for example, carboxylesterases from human monocytes were found to be inactive toward some endogenous thioesters [35] [146], In contrast, allococaine benzoyl thioester was found to be a good substrate of pig liver esterase, human and mouse butyrylcholinesterase, and mouse acetylcholinesterase [147],... 

Although the use of an epoxide hydrolase was already claimed for the industrial synthesis of L- and meso-tartaric acid in 1969 [51], it was only recently that applications to asymmetric synthesis appeared in the hterature. This fact can be attributed to the limited availabihty of these biocatalysts from sources such as mammals or plants. Since the production of large amounts of crude enzyme is now feasible, preparative-scale applications are within reach of the synthetic chemist. For instance, fermentation of Nocardia EHl on a 701-scale afforded > 700 g of lyophilized cells [100]). 

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