Normal human urine was found to contain β (1-3) N-acetylglucosaminyltransferase catalyzing the transfer of N-acetylglucosamine from UDP- GlcNAc to Nacetyllactosamine and lactose. Lacto-N-tetraose which carries the terminal Galβ (1-3) GlcNAc structure was a poor acceptor. The product of the transferase reaction with N-acetyllactosamine as acceptor was identified by methylation analysis as GlcNAcβ (l-3) Galβ (1-4) GlcNAc. The β-linkage of the GlcNAc in the synthesized trisaccharide was confirmed by the action of the specific β-N-acetylhexosaminidase. The enzyme requires Mn²⁺ ions for its activity, shows a broad pH optimum from 7 to 9, and appears to have a molecular weight of about 200, 000 as estimated by Sephadex gel filtration.

View full abstract

Adequate conditions for the potency test of hepatitis B (HB) vaccines in mice were looked for. Preliminary tests showed that BALB/c female mice of 5 weeks of age are adequate for the test. An immunization period of 5 weeks was found satisfactory for the test. Under these conditions, mice were immunized with each of serial dilutions of the test vaccine and a reference vaccine. The use of the parallel line assay method and the expression of the potency relative to that of the reference vaccine gave a reliable estimate of the potency of HB vaccine.

View full abstract

Hepatitis B surface antigen (HBs antigen) was examined for elicitation of IgE production by injection into mice. The Prausnitz-Küstner (PK) -type skin test in the rat was employed for detection of IgE antibody to HBs antigen, because no sufficient purified HBs antigen was available as the challenging antigen for the passive cutaneous anaphylaxis (PCA) test in rats. The positive PK test was considered to be due to IgE antibody, since the active principle was inactivated by heating the sera at 56 C for 30 min, did not bind to protein A and was eliminated by anti-mouse IgE antisera. These data indicate that the PK-type test in rats can be used for detection of mouse IgE antibody when the amount of a test sample is not sufficient for the PCA test in rats.

View full abstract