Enzymes efficiency

Loss of enzyme efficiency was due to short and long-term PG distribution between the different products (Fig. 2). 

Although the size distribution of fragments from heparinase (and hep-aranase) digests reflects the relative content of regular sequences 5 in different heparin preparations and fractions, these sequences may be quantitated only when the enzyme efficiency is high, and products are... 

The cumulative evidence that each individual human being has a distinctive pattern of enzyme efficiences is hard to refute on any rational basis. Furthermore, inter-individual variations in enzyme efficiencies in normal individuals, insofar as they have been determined, are not of the order of 20 to 50 per cent, but are more often at least 3- or 4-fold. Differences of 10- to 50-fold ( ) have been observed in a substantial number of cases even when the number of normal individuals tested was small. 

In 1991 bile-acid secretion was shown to be energy driven by a 110-kDa glycoprotein that was dependent on ATP. This protein was subsequently characterised as liver ecto-ATPase by Sippel and co-workers. However, while further work with COS cells showed that expression of ecto-ATPase enhanced secretion of bile acids purified canalicular membranes lacking this enzyme efficiently exported bile acids showing that at least one other bile-acid transporter existed. ... 

Another useful quantitative definition of enzyme efficiency is specific activity. The specific activity of an enzyme is the number of enzyme units or katals per milligram of protein. This is a measure of the purity of an enzyme. If a solution contains 20 mg of protein that express 2 units of activity (33 nkatals), the specific activity of the enzyme is 2 units/20 mg = 0.1 units/mg or 33 nkatals/20 mg = 1.65 nkatals/mg. As an enzyme is purified, its specific activity increases. That is, during purification, the enzyme concentration increases relative to the total protein concentration until a limit is reached. The maximum specific activity is attained when the enzyme is homogeneous or in a pure form. 

V. S. Narayan and A. M. Klibanov, Are water-immiscibility and apolarity of the solvent relevant to enzyme efficiency Biotechnol. Bioeng. 1993, 41, 390-393. 

In a review of the proficiencies of enzymes and how they achieve them, it was claimed that ground-state conformations and transition state stabilization cannot explain the very large efficiencies of enzymes instead, they must proceed, it was concluded, by covalent enzyme-substrate intermediates.73 A riposte to this contentious hypothesis has appeared, claiming that account was not taken of the fact that high enzyme efficiency is determined by the value for the water reaction k0 rather than by the enzymatic rate constant kcat/kM.14... 

Lignocellulosic biomass is a valuable and plentiful feedstock commodity and its high cellulose and hemicellulose content (about 80% of total) provides considerable potential for inexpensive sugars production. However, enzymatic deconstruction of these polysaccharides remains a costly prospect. Strides in cellulase cost reduction have been made, yet further improvements are needed to reach the goal of 0.10/gal of EtOH expected to enable this new industry. Strategies to reach this goal will combine reduction in the cost to produce the needed enzymes as well as efforts to increase enzyme efficiency (specific activity). As this work proceeds, the more easily attained achievements will be made first, and thus the overall difficulty increases with time. 

B. Enzyme Efficiency Under Waste-Treatment Conditions... 

A major hurdle that must be overcome before enzymatic treatment can become a reality is the price of the enzyme [24]. Recent research has focused on improving the economics of enzymatic systems through the direct use of plants or plant materials that contain enzymes, the use of crude enzyme extracts, the development of cloned cells that can be stimulated to produce enzymes efficiently in reactor systems, and transgenic manipulation of plants to stimulate enzyme production. Specific examples of some of these efforts are described below. 

When structural information for a protein is lacking, identifying appropriate residues for mutational analysis is difficult. In such cases, random mutagenesis coupled with selection can provide a powerful means of analysis. We have used such an approach to examine how the seventeen C-terminal residues of BsCM contribute to enzyme efficiency [70],... 

In Eq. (70.1), the product of the bimolecular rate constant ( cat/ m) and the enzyme active site concentration ([E]) is the first order rate constant. The amount of enzyme to be injected for degradation of toxic molecules in a very short time depends on the enzyme efficiency, i.e. k JKm- The higher the efficiency, the lower the dose of enzyme to be administered. The enzyme concentration that reduces the OP concentration to a nontoxie concentration in time t is ... 

Removes Iron, copper and other Ions with no loss of enzyme efficiency. Blend of chelates. 

By the sequential use of different enzymes, efficient synthesis of partially acylated disaccharides can be achieved. 6-0-acetyl glucal 5 (Scheme 4), prepared... 

A distinguishing element of avian physiology is ho-moiothermy, or metabolic activity that maintains the body temperature within a narrow, warm range optimized for muscular functions and enzyme efficiency. (Mammals and some other vertebrates are also warmblooded.) Homoiothermy is a crucial physiological trait that allows almost all bird species to have an extremely active lifestyle. It also allows some species to live year-round in cold environments. 

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