Glycopeptide composition of hepatitis B surface antigen.

Three major polypeptides of hepatitis B surface antigen (HBsAg), with mol. wt. 22,000 (p22), 27,000 (p27) and 68,000 (p68), were separated by preparative SDS-PAGE. These three peptides as well as intact HBsAg were found to have almost identical amino acid compositions and carbohydrate was detected in p27 and p68 by PAS staining. Papain treatment of p68 produced two distinct peptides p27 and p22. Moreover, when an artificial mixture of p27 and p22 in a ratio of 1:1 was treated with 0.2 M-periodate for 30 min at 37 degrees C, only p22 was detectable. These results suggest that p68 is composed of p27 and p22, and that p27 is a glycosylated product of p22. Thus, from the evidence obtained, it is possible that p22 (22,000 peptide) is the minimum size of the unique hepatitis B virus (HBV) gene product involved.

Non-B hepatitis in Japanese recipients of blood transfusions: clinical and serologic studies after the introduction of laboratory screening of donor blood for hepatitis B surface antigen.

Cases of hepatitis virus infection in Japanese recipients of blood transfusions were serologically and clinically analyzed after the introduction of laboratory screening of donor blood for hepatitis B surface antigen by counter immunoelectrophoresis. Non-A, non-B hepatitis occurred in 116 (10.7%) and hepatitis type B in nine (0.9%) of the 1,082 recipients. The incubation period of the post-transfusion non-A, non-B hepatitis cases varied from two to 33 weeks, but most occurred within 15 weeks. In 97 (83.6%) of the 116 cases of non-A, non-B hepatitis studied, the duration of abnormal elevation of the level of serum alanine aminotransferase (glutamic-pyruvic transaminase [SGPT]) was 16 weeks. The cases of non-A, non-B hepatitis could be divided into three groups according to the pattern of elevation of SGPT levels. These findings may suggest either a multiple etiology for non-A, non-B hepatitis or a variety of clinical symptoms with a single etiology for the infection.

Hepatitis "C" antigen in non-A, non-B post-transfusion hepatitis.

Evidence for a new hepatitis-specific antigen has been obtained from double immunodiffusion assays between acute and convalescent sera obtained from patients with non-A, non-B post-transfusion hepatitis. The designation hepatitis C (HC) antigen is proposed. HC was found in the acute-phase sera of all 13 non-A, non-B post-transfusion hepatitis patients with longer incubation and duration periods (type 2) tested, but only transiently in 4 out of 10 acutephase sera obtained from patients with type 1 non-A, non-B hepatitis, with shorter incubation and duration periods. The antigen was also detected in 2 out of 16 single specimens obtained during the acute phase from acute hepatitis patients who had not received a blood-transfusion. This suggests presence of a carrier state. No patients with alcoholic hepatitis and no healthy blood-donor carried HC antigen. The antigen seems distinct from those of hepatitis A and B (surface and core). It migrated in the serum beta-globulin region and had a buoyant density of 1.30 and a molecular weight between 100 000 and 300 000. Antibodies against HC antigen were found in only 30% of the type-2 non-A, non-B post-transfusion hepatitis patients and did not persist for long. However, these antibodies were directed specifically against HC antigen and moved in a manner similar to 7S globulin on rate-zonal centrifugation.

The specific reduction of a and d antigenic determinants after periodate treatment of hepatitis B surface antigen (HBsAg).

HBsAg antigenicity was found to be sensitive to periodate treatment. Antigenic determinants a and d were especially sensitive, losing almost all of their activity, while determinants r and w were found to be quite stable. Also, it is now possible to prepare the monospecific antibodies, anti-r and anti-w, by the use of this new, simpler procedure.

Carbohydrate composition of hepatitis B surface antigen.

The content and composition of carbohydrate in hepatitis B surface antigen HBsAg) were clarified by gas chromatography. A value of 75-8 microgram carbohydrate per mg of protein was obtained. The main components were N-acetylglucosamine, mannose, galactose and sialic acid and the minor one was fucose. No N-acetyl-galactosamine was detected. The fact that no sugar was detected in lipid fractions suggests that the sugar in HGsAg exists almost exclusively in the form of glycoprotein and there is no glycolipid.

Conformational studies of Australia antigen by optical rotatory dispersion and circular dichroism.

The optical rotatory dispersion and circular dichroism of intact, 8 m urea- or sodium dodecyl sulfate-treated, and carbamidomethylated Australia antigen indicated that the antigen possesses a high alpha-helical content similar to human high-density lipoproteins.

Reduction and reoxidation of Australia antigen: loss and reconstitution of particle structure and antigenicity.

Reduction of Australia antigen with dithiothreitol resulted in the loss of antigenicity and morphological integrity. Oxidation of the reduced Australia antigen reconstituted both of these characters.