Studies on the sugar chains of interferon-gamma from human peripheral-blood lymphocytes

Sugar chains of interferon-gamma (IFN-gamma) from human peripheral-blood lymphocytes (PBL) were liberated by hydrazinolysis. After N-acetylation, the reducing end residues of the sugar chains were tagged with 2-aminopyridine and the pyridylamino (PA-) derivatives were purified by gel filtration and reversed-phase HPLC. Five major PA-sugar chains were obtained. The structure of each PA-sugar chain was estimated by comparing its elution times on anion exchange, reversed-phase, and size-fractionation HPLC with those of PA-sugar chains of IFN-gamma from the human myelomonocyte cell line HBL-38 (Yamamoto, S. et al. (1989) J. Biochem. 105, 547-555) as standards, and also by comparison of their elution times after partial desialylation. The results showed that IFN-gamma (PBL) contained mono- and disialo-biantennary structures with 0 or 1 mol of fucose residue, as found for IFN-gamma (HBL-38), but the N-acetylneuraminyl alpha 2-6 linkage was dominant in IFN-gamma (PBL), unlike IFN-gamma (HBL-38), which contains both N-acetylneuraminyl alpha 2-3 and alpha 2-6 linkages.     

A Relationship between Papaincatalyzed Aminolysis of Ethyl Hippurate by Amino Acid Esters and Their Incorporation into Ovalbumin Hydrolysate during the Plastein Reaction

The effects of the colloidal properties of emulsion particles and the conformation of tryptic digests of soybean glycinin, the emulsifiers, on emulsion properties were investigated. The digests were separated into some fractions, and the properties of intact glycinin, two kinds of the best were examined. The diameter of the emulsion particles measured by spectroturbidimetry was not very different among the best emulsifiers and intact glycinin in spite of the difference in emulsifying ability; however, a new parameter, flocculation strength, which is the rigidity of the flocculated structure and is defined as the minimum detergent concentration for the dissociation of flocculation, closely and negatively related to the short term emulsion stability. The amount of adsorbed protein on the surface of the emulsion particles was also related to the long term emulsion stability. The two best emulsifiers were analyzed by gel filtration and circular dichroism. The emulsifiers contained large molecular components whose molecular weight and secondary structures were similar to intact glycinin. The conformational stability of the emulsifiers was evaluated by the change in emission maxima of the intrinsic fluorescence of the proteins against changing urea concentration, and the surface hydrophobicity of the proteins was estimated by the binding of l-anilino-8-naphthalene sulfonate (ANS). The emulsion stability increased with decreasing conformational stability and increasing surface hydrophobicity of the emulsifier proteins.     

Additional genes essential for replication of the mini-F plasmid from origin I

Summary We isolated a series of Tn5-insertional mutants from the mini-F plasmid, which has a deletion in the origin II region and replicates exclusively from origin I, and found that the mutants that had Tn5 in either the F4 or the F5 gene were defective in their replication. It is concluded that, in addition to the F3 gene on which we have reported previously, both the F4 and the F5 genes are essential for the replication from origin I.