Plasmid DNA partitioning and separation using poly(ethylene glycol)/poly(acrylate)/salt aqueous two-phase systems.

Phase diagrams of poly(ethylene glycol)/polyacrylate/Na(2)SO(4) systems have been investigated with respect to polymer size and pH. Plasmid DNA from Escherichia coli can depending on pH and polymer molecular weight be directed to a poly(ethylene glycol) or to a polyacrylate-rich phase in an aqueous two-phase system formed by these polymers. Bovine serum albumin (BSA) and E.

Use of 18O water and ESI-MS detection in subsite characterisation and investigation of the hydrolytic action of an endoglucanase.

We present a novel method for investigating subsite-substrate interactions of glycoside hydrolases and the determination of the oligosaccharide cleavage point based on the analysis of the hydrolysis products produced in the presence of (18)O-labelled water. Conventional techniques for such determination of the hydrolysis pattern call for the chemical modification of the substrate, whereas the method presented makes it possible to use natural substrates, utilising the selectivity and sensitivity of mass spectrometry. This method is very useful for the detection and analysis of enzyme-catalysed hydrolysis, provided that the conditions are chosen where (18)O incorporation without the presence of the enzyme is absent or undetectable.

Extraction of yeast mitochondrial membrane proteins by solubilization and detergent/polymer aqueous two-phase partitioning.

Identification and characterization of membrane proteins is of increasing importance in modern proteomic studies. It is of central interest to have access to methods that combine efficient solubilization with enrichment of proteins and intact protein complexes. Separation methods have been developed based on nondenaturing detergent extraction of yeast mitochondrial membrane proteins followed by enrichment of hydrophobic proteins in aqueous two-phase system.

Endoglucanase sensitivity for substituents in methyl cellulose hydrolysis studied using MALDI-TOFMS for oligosaccharide analysis and structural analysis of enzyme active sites.

The properties of modified cellulose polymers, such as methylcellulose, are significantly influenced by the distribution of substituents along the polymer backbone. This distribution is difficult to determine due to the lack of suitable analytical methods. One approach is to use cellulose-degrading enzymes to gain information from the capability of the enzymes to cleave the bonds between glucose units.

Studies of the separation and characterisation of mixtures of starch and cellulose derivatives by use of chromatography and mass spectrometry.

In this work a method was developed for characterisation of commercially available polymers consisting of mixtures of substituted cellulose and starch. Selective hydrolysis with specific enzymes was used to achieve separation of the two polymers in the mixture. Enzymes hydrolysing (1-->4)-alpha-D and (1-->6)-alpha-D-glycosidic bonds were used for the starch part and enzymes hydrolysing (1-->4)-beta-D-glycosidic bonds for the cellulose part.