Enzyme solubility

The study of enzymes is important because every syndietic and degradation reaction in all living cells is controlled and catalyzed by specific enzymes. Many of these reactions are the soluble enzyme-soluble substrate type and are homogeneous in the liquid phase. 

The following protocols make use of the compounds adipic acid dihydrazide and carbohy-drazide to derivatize molecules containing aldehydes, carboxylates, and alkylphosphates. The protocols are applicable for the modification of proteins, including enzymes, soluble polymers such as dextrans and poly-amino acids, and insoluble polymers used as micro-carriers or chromatographic supports. 

Covalently modified enzymes soluble in organic media... 

Alcohol and aldehyde oxidation. Although a microsomal enzyme system has been demonstrated, which oxidizes ethanol (see above), probably the more important enzyme in vivo is alcohol dehydrogenase, which is a cytosolic enzyme (soluble fraction) and is found in the liver and also in the kidney and the lung. 

Typical kinetic analyses of enzyme-substrate systems are based on observed rates of enzyme-catalyzed reactions over a range of enzyme and substrate concentrations. Analyses of this type are commonplace for soluble enzyme-soluble substrate systems in which measures of substrate and... 

Initial reaction rates at temperatures from 40°C to 60°C increase when the pressure is increased from 80 bar to 300 bar, and decrease with higher pressure (Figure 3). Probably, at lower pressure the adsorption of the ester to the enzyme takes place, causing inhibition of the enzyme. Solubility of the ester increases with higher pressure, so SC C02 flushes away the ester from the enzyme and activity of the enzyme increases. The same explanation was found in lit. [6], On the other hand, at high pressure too much water may be extracted from the biocatalyst resulting in lower reaction yields [7],... 

I. Soluble enzyme-insoluble substrate n. Insoluble enzyme-soluble substrate in. Soluble enzyme-soluble substrate... 

A simple, rapid, and inexpensive in vitro method for estimating food iron availability is described. The method involves a simulated gastrointestinal digestion using commercially available enzymes. Soluble, low molecular weight iron is used as an indicator of iron availability. Similar results are obtained when the soluble iron is intrinsic food iron or added extrinsic radioiron. 

For most screening procedures and bioindustrial enzymatic applications, it is essential that adequate amounts of enzyme can be produced through heterologous expression in E. coli or similar strains of bacteria. Unfortunately, difference between eukaryotic and prokaryotic protein folding means that enzymes that express well in eukaryotes may not express well in prokaryotes, because of different folding chaperones, and so on. Thus, there is often a pressing need to improve enzyme solubility and expression before enzymes can be used. 

Ward lists several key enzyme properties that are important for applications in bioprocessing. The primary considerations are the specificity of an enzyme with respect to the type of reaction being carried out, the substrates used, and the nature of the product. Another vital aspect for efficient processing is the enzyme solubility and stability at different pH and temperature conditions. The structure, charge, and shape of an enzyme must also be known when purification and recovery of the enzyme are desirable. 

Starch, a polymer formed from glucose monomers, is the principal storage carbohydrate of plants and commercially is obtained primarily from corn. The industrial process involves, first, acid or enzyme (soluble bacterial a-amylase) catalyzed hydrolysis of aqueous suspensions of gelatinized starch to obtain a... 

Methods of assay (m) = methylation (p) = periodate oxidation (e) = enzymic. B.V. = Blue Value (compare Refs. 3 and 4). Xmax = wavelength of maximum absorption of polysaccharide-iodine complex. Priming activity toward P-enzyme soluble starch = 1.0. Priming activity toward muscle phosphorylase glycogen = 100, corn amylopectin = 63. Molecular weight, 64,000 (compared with about 100,000 for the parent amylose). 

Chorismate mutase Conversion to monomeric enzyme (solubility) Functional monomeric enzyme... 

To achieve true homogeneous catalysis, enzyme solubility may be increased by coupling polyethyleneglycol to its surface1871. The coupling may alter the stability, activity and selectivity of the enzyme. 

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