Cultured Clostridium botulinum strains produce progenitor toxins designated as 12S, 16S, and 19S toxins. The 12S toxin consists of a neurotoxin (NTX, 7S) and a non-toxic non-hemagglutinin (NTNH). The 16S and 19S toxins are formed by conjugation of the 12S toxin with hemagglutinin (HA), and the 19S toxin is a dimer of the 16S toxin. Type A cultures produce all 3 of these progenitor toxins, while...

Rapid formation of poliovirus-neutralizing antibody was observed in the rabbit. 19S type antibody was detectable 8 to 12 hours following a single intravenous virus injection and the induction period was of the order of 4 to 5 hours or less. The production of 7S antibody had a longer lag phase (1(1/2) to 2 days) and it was formed at slower rate. The observed rate of early 19S and 7S antibody for...

The main conclusion from this study is that C3 receptors are not required for the generation from B cells of a thymus-dependent 7S antibody response. The requirement for C3 receptors on the precursors of antibody-forming cells was studied in an adoptive transfer system using thoracic duct lymphocytes (TDL) from primed rats as a source of precursors and irradiated recipients as hosts. 7S precurs...

Brazil nut storage proteins, 2S albumin, 7S vicilin, and an 11S legumin, were purified using column chromatography. Analytical ultracentrifugation of the purified albumin, vicilin, and legumin proteins, respectively, registered sedimentation coefficients of 1.8, 7.1, and 11.8 S. Under reducing conditions, the major polypeptide bands in 2S albumin were observed at 6.4, 10-11, and 15.2 kDa. The 7...

Background The 7S vicilin-like seed storage globulins represent an important class of food allergens. In many plants, the 7S globulins are synthesized as a precursor polypeptide, which undergoes post-translational proteolysis to remove a portion of the N-terminus to produce the mature protein sequence. However, the fate of the cleaved N-terminal region is largely unknown. We have identified and...

Rats were immunized with Salmonella adelaide flagella. By zone centrifugation of serum samples in sucrose gradients, it was shown that, as in many other systems of antibody formation, the first response was the formation of 19S, mercaptoethanol (ME)-sensitive antibody. This was quickly replaced by 7S, ME-insensitive antibody. Popliteal lymph node cell suspensions were prepared, and cells with a...

We have analyzed the transcription of a recently isolated human 7S K RNA gene in vitro and in vivo. In contrast to hitherto characterized class III genes (genes transcribed by RNA polymerase III), the coding sequence of this gene is not required for faithful and efficient transcription by RNA polymerase III. In fact, a procaryotic vector DNA sequence was efficiently transcribed by RNA polymeras...

The globulins from wheat caryopses were found to consist primarily of protein sedimenting at approximately 3S and 7S. These proteins displayed a molecular weight distribution similar to that of the purified vicilin-like fractions from oat and pea, with variations occurring in the isoelectric points and relative quantities of their major subunits. concanavalin A Sepharose chromatography suggeste...

A previous paper in this series (1) described marked differences in the kinetics of the formation of poliovirus (PV)-neutralizing antibody of 19S and 7S type. I t was also reported (2) that the antibodies produced in the rabbit after a single PV injection showed progressive changes in their electrophoretic mobility and avidity. The present study analyzes these sequential changes in the mobility...

Four new 7,8-epoxycembranoids, namely (2S*,7S*,8S*,12R*,1Z,3E,10E)-7,8:2,16-diepoxycembra-1(15),3,10-trien-12-ol (1), (2S*,7S*,8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15),3,12(20)-trien-11-ol (2), (4S*,7S*,8S*,1Z,2E,11E)-16-acetoxy-7,8-epoxycembra-1(15),2,11-trien-4-ol (3), and (7S*,8S*,15S*,1E,3E,11E)-7,8-epoxycembra-1,3,11-trien-15,16-diol (4) were isolated from a Chinese soft coral Lobophyt...