Enzyme content

Persano Oddo, L. and Pulcini, P. (1999). A scientific note on the Phadebas method for honeys with low enzyme content. Apidologie 30, 347-348. 

Fig. 4. Anaerobic titration of xanthine oxidase with xanthine at pH 8.2 with a reaction time of 2 min. at about 20°. The integrated intensity of the Rapid molybdenum EPR signals (in arbitrary units) is plotted against the number of moles of xanthine added per mole of active enzyme. Activity/A4jo for the enzyme samples used was 112 corresponding to an active enzyme content of 57%. Thus the molar ratios of xanthine/total xanthine oxidase have been multiplied by 1.76 to refer to the active form only. Some of the EPR spectra (recorded at about — 130° and 9.3 GHz) are reproduced to show the changes in signal type as the amount of xanthine is increased. (Data re-calculated from ref. 88, with intensities corrected for variations in tube diameter and enzyme concentration calculated in terms of active enzyme.)...

Table 10.1 Antioxidant and cytoprotective enzyme content in a variety of rat tissues.

The decreased denaturating action of the precursor and procedure enables one to immobilize reduced amounts of biomaterial. It was demonstrated in Ref. [55] that biocatalysts prepared by entrapping endo-l,3-P-D-glucanase and a-D-galactosidasc in amounts comparable to that in living cells had a reasonable level of activity. When the TEOS is applied, the enzyme content in silica matrix can be up to 20-30 wt.% to counterbalance losses due to denaturation [50]. 

TABLE 28-2 Enzyme Content of Selected Pancreatic Enzyme Preparations ... 

The increase in enzyme content (activity and/or amount) due to xenobiotic challenge, which may result in more rapid metabolism of a chemical. 

Enzymes occupy an important place in analytical biochemistry and many investigations require their detection and quantitation. Studies of the enzyme content of blood plasma are particularly useful in clinical biochemistry both in the monitoring of normal metabolic processes and in the detection of abnormal levels of enzyme production or release. Enzyme assays also provide convenient methods for assessing the quality of foodstuffs and checking the efficiency of sterilization and pasteurization processes. 

Studies of the enzyme content of cells frequently involve the use of coarse tissue samples of either animal or plant origin. In such cases some preliminary dissection of the tissue may be necessary to isolate the relevant tissue components and remove unwanted structural material such as collagen, cellulose, etc., before moving on to the more critical disruption of the cells. Sometimes it is possible to use the technique of tissue culture to provide pure cell preparations for subsequent studies. 

Several examples of the binding of enzymes to poly(vinyl alcohol) are in the literature. These could possibly be used to treat enzyme deficiency diseases. In a recent example, trypsin was immobilized on poly(vinyl alcohol) fibers using maleic dialdehyde or bromal. While the reaction was more complete with bromal, the reaction with maleic dialdehyde gave a better support which showed decreasing activity with increasing enzyme content. The activity of the bromal activated system was independant of the enzyme content (52 ). Trypsin and papain were attached to poly(vinyl alcohol) by the reaction sequence shown in Equation 13. In this case, the crosslinked poly(vinyl alcohol) is treated by the 1,3-dioxalone derivative and then converted to either the isothiocyanate or the diazonium salt for coupling with the enzyme. The bound enzymes showed significant, altho reduced, activity in each case (53). 

In a separate experiment, groups of male CDl mice were given intraperitoneal injections of 0-200 mg/kg bw ciimamyl anthranilate daily for three days. At doses of 20 mg/kg bw and above, there were dose-dependent increases in relative liver weight, total cytochrome P450, and cyanide-insensitive palmitoyl-CoA oxidation. The hepatic effects of cinnamyl anthranilate are apparently due to the intact ester, since neither its expected metabolites alone nor an equimolar mixture of the hydrolysis products, cinnamyl alcohol and anthranilic acid, had a significant effect on the weight or marker enzyme content of mouse liver (Viswalingam Caldwell, 1997). 

Density gradients are widely used in separating and purifying biological samples. In addition to this preparative application, measurements of s can be made. Gradient techniques have been used to isolate and purify the sub-cellular components, microsomes, ribosomes, lysosomes, mitochondria, peroxisomes, chloroplasts, and others. After isolation, they have been biochemically characterized as to their protein, lipid, nucleic acid, and enzyme contents. 

Artichoke prolongs picking period Barley enzyme content increased Bean more rapid emergence of plant... 

By substituting Eq. (2.8) into Eq. (2.7), the rate of reaction can be expressed as a function of Cs and C , of which CE cannot be easily determined. If we assume that the total enzyme contents are conserved, the free-enzyme concentration CE can be related to the initial enzyme concentration C ... 

Again, if we assume that the total enzyme contents are conserved,... 

Tylenol inhibits the peroxidase activity and aspirin inhibits the cyclooxygenase activity. 22.46 because dead heart muscles spill their enzyme contents into the serum 22.48 They are both basic amino acids. 

Figure 5.11 Influence of radius on the effectiveness factor of a spherical porous immobilized enzyme particle (enzyme contents [mg cm-3] are listed besides curves) (specific activity 100 IU, Defr= 4 x 10"8 m2 s" [S)/KM = 10) (Regan, 1974).

In the thermolysin-catalyzed solid-to-solid dipeptide synthesis of equimolar amounts of Z-Gln-OH and H-Leu-NH2 as model substrates, the water content was varied from 0 to 600 mL water (mol substrate)-1 and enzyme concentration in the range 0.5-10 g (mol substrate)-1 to achieve 80% yield and initial rates of 5-20 mmol (s kg)-1 (Erbeldinger, 1998). When the water content is decreased from the 1.6-molal lowest substrate concentration, the initial rate increases tenfold to a pronounced optimum at 40 mL water (mol substrate)-1 and falls to much lower values in a system with no added water, and to zero in a rigorously dried system. The behavior at a higher water content was demonstrated through variation of the enzyme content to be caused by mass transfer limitations at low water levels, the effects reflect the stimulation of the enzymatic activity by water. Preheating of the substrates or ultrasonic treatment had no significant effect on the system. 

Fig. 1. Effect of immobilized lipase contents on the butyl butyrate synthesis at 37°C for 24 h. A molar ratio between butyric acid and butanol of 1.25 was used for enzyme contents of 5,10, 25, and 50 mg/mL.

Proksch, E., Elias, P.M., and Feingold, K.R. Regulation of 3-hydroxy-3-methylglutary 1-coenzyme A reductase activity in murine epidermis. Modulation of enzyme content and activation state by barrier requirements. J. Clin. Invest. 1990, 85 874-82. 

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