A form of sulphotransferase capable of sulphating dehydroepiandrosterone and other steroids was purified from cytosol prepared from human liver. Dehydroepiandrosterone sulphotransferase was purified 621-fold when compared with the activity in cytosol using DEAE-Sepharose CL-6B and adenosine 3',5'-bisphosphate-agarose affinity chromatography. During affinity chromatography, dehydroepiandrosterone sulphation activity could be resolved from p-nitrophenol sulphation activity catalysed by phenol sulphotransferase by using a gradient of adenosine 3'-phosphate 5'-phosphosulphate. The purified enzyme was most active towards dehydroepiandrosterone but was capable of conjugating a number of other steroids, including pregnenolone, androsterone and beta-oestradiol. No activity towards p-nitrophenol or dopamine, substrates for the phenol sulphotransferase, was observed with the pure enzyme. A single band with a subunit molecular mass of 35 kDa was observed by Coomassie Blue staining following SDS/polyacrylamide-gel electrophoresis of the purified enzyme. A molecular mass of 68-70 kDa was calculated for the active form of the enzyme by chromatography on Sephacryl S-200, suggesting that the active form of the enzyme is a dimer.

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Nontypeable Haemophilus influenzae (NTHi) is one of the leading causative agents of bacterial otitis media, and no vaccine has been shown to be effective against it. Three outer membrane lipoproteins of NTHi have been investigated extensively and are leading candidates for inclusion in a vaccine against this organism. Hi-PAL (P6), recombinant PCP (rPCP), and e (P4) proteins are antigenically conserved among NTHi strains and elicit bactericidal and protective antibodies. A genetic fusion of the rPCP and Hi-PAL proteins has also been reported. Mixtures of these proteins were used for active immunization experiments in the chinchilla model of otitis media. Chinchillas were immunized either with a mixture of all three lipoproteins or with the mixture of rPCP-PAL hybrid plus e protein. When these animals were challenged with a NTHi strain injected directly into the middle ears, no protection from infection or disease, as measured by otoscopy, was observed in either group. However, effusion and inflammation measured by tympanometry were significantly reduced in animals immunized with the three lipoproteins. Animals that had been immunized with either whole NTHi cells or total outer membranes and then challenged with the homologous strain were significantly protected from both infection and disease, as determined by tympanometry and otoscopy. Unlike other animal antisera, chinchilla antisera against the purified proteins had no bactericidal activity against NTHi but did fix complement on the cell surface. Thus, the chinchilla immune responses to mixtures of these lipoproteins differ from the immune responses observed in other animal species. Further evaluation of these proteins for their vaccine potential remains to be done.