Development of gel filtration and specific analyses of urinary carbohydrate and protein material

Hitherto investigations into urinary carbohydrate and proteinaceous macromolecular material has largely been restricted to non-dialysable fractions. We found that this limits the investigation to less than 1% of the total material present and we present a method for direct analysis of urine without prior concentration or extraction. This method extends existing techniques allowing deeper investigation into necessary and important chemical aspects of health and disease. The method is based on gel filtration using Bio-Gel P2. Means included to overcome the observed adsorption by the gel matrix of relevant material depend on use of high ionic concentration buffers for column elution. The problems of bacterial contamination of the gel matrix are discussed and the use of presterilised urine samples is proposed to prevent contamination. The coupling of the gel filtration column to three specific automated analyses allows simultaneous determination of uronic acid, neutral sugar and proteinaceous material.

Active water-insoluble derivatives of papain and other enzymes based on preformed diazonium-type supports

Papain (EC 3.4.22.2) has been coupled to supports of titanium (IV) oxide and cellulose, which are particulate and pre-coated with diazotised 1,3-diaminobenzene, giving water-insoluble and stable derivatives which possess low proteolytic activity but high esterolytic activity. In addition the reversible binding of zinc (II) at the active site of papain has been exploited to inhibit protectively the enzyme during its linkage to the aforementioned supports, thereby yielding water-insoluble derivatives of papain having superior activity upon reactivation with EDTA. Application of the improved procedure of enzyme coupling to macroporous cellulose particles gave a water-insoluble derivative of papain having further enhanced proteolytic activity. Other properties of the water-insoluble derivatives of papain and of similarly prepared water-insoluble conjugates of urease (EC 3.5.1.5) and cholinesterase (EC 3.1.1.8) with cellulose are also reported.

Structural identification of isomeric O-trimethylsilyl derivatives of some hexuronic acids

The structures of the isomeric products obtained on trimethylsilylation of naturally occurring hexuronic acids and their sodium salts and lactones have been established by the application of n.m.r. (for anomeric configuration) and mass spectrometry (for ring size). The equilibria of some of the hexuronic acids in methyl sulphoxide involved a larger proportion of furanoid forms than those in water or pyridine. The proportion of furanoses was also increased by the addition of hexamethyldisilazane. Kinetic evidence indicated that two molecules of each hexuronic acid interacted autocatalytically during mutarotation.

Ovarian dysgenesis and chromosome abnormalities

The association of ovarian hypoplasia with trisomy 18 in 6 infants and trisomy 13 in 5 infants and 1 fetus is reported. Three infants also had thymic hypoplasia. The possible etiology of ovarian dysgenesis is discussed in relation to a variety of clinical and experimental associations.

The use of titanium (IV) oxide for the immobilisation of carbohydrate-directed enzymes

The use of particles of porous titanium (IV) oxide as a suitable matrix for enzyme immobilisation has been investigated with dextranase. Treatment of the particles with enzyme in the presence and absence of ammonium ions showed that the presence of ammonia induced a greater coupling of protein, whereas a greater retention of enzyme specific activity was achieved in the absence of ammonia. Properties of the immobilised enzyme include a pH-dependence and reversibility of the coupling between enzyme and matrix. The immobilised dextranase was most stable at pH 5.0. Automated analytical techniques for measuring the activity of dextranase and other polysaccharidases in soluble and insoluble forms are also reported.

The fully automatic ion-exchange and gel-permeation chromatography of neutral monosaccharides and oligosaccharides with a Jeolco JLc-6AH analyser

Experiences with a Jeolco JLC-6AH carbohydrate analyser used to provide a fully automated analysis service for neutral mono- and oligo-saccharides have been summarised. Modifications have been made to the equipment to extend its application, and a method for routine separations of oligosaccharides (d.p. 2--15) has been established. The degree of separation achieved is far superior to that which may be obtained by gel-filtration techniques under gravity- or peristaltic-pump-aided flow. The versatility and adaptability of equipment for use with assays other than the standard orcinol-sulphuric acid reaction shows that it is not too inconvenient to interchange between various assays and separations.

Magnetic, immobilised derivatives of enzymes

A novel, water, insoluble, stable coating has been attached to various metals, which is capable of covalent attachment to enzymes. The coating (aminobenzoic acid-formaldehyde resin) can be attached to nickel, cobalt, tin, iron, and aluminium. beta-D-Glucosidase has been attached to the coated metals by diazotisation of the coating. The stability and usefulness of the resulting, metallic enzyme-preparations is discussed with special emphasis on the value of ferromagnetic supports for enzymes.