Oxidation of the Met residues of human interleukin 6 (IL‐6) molecule has been performed. Reactivity of Met for the oxidation reaction was found to decrease in the order of Met50, Met118, Met185, ...Met162, and Met68. Chemical modifications involving oxidation and carboxypeptidase A digestion of IL‐6 have led to the assignments of the methyl proton resonances of Met162 and Met185, respectively. The hydroxynitrobenzyl chromophore attached to Trp158 in the IL‐6 molecule showed a different absorption spectrum when the labeled IL‐6 was bound to the soluble IL‐6 receptor. This result indicates that Trp158 is near the receptor‐binding region in IL‐6. On the basis of the
1
H‐NMR and chemical modification data, it has been concluded that Trp158 is in spatial proximity to Met162, His165 and Met185. The receptor‐binding activity decreased with an increase in the number of oxidized Met residues. Of these five Met residues, Met162 was the residue in which the receptor‐binding activity decreased in the most parallel degree with that of the oxidation reaction.
B-cell stimulatory factor 2 (BSF-2) is a lymphokine which induces the final maturation of B cells. BSF-2 acts on a variety of cells other than B cells, and moreover, expression of BSF-2 mRNA is ...detected in interleukin-1 β-stimulated glioblastoma and astrocytoma cell lines. Here, we studied the function of BSF-2 on pheochromocytoma PC12 cells, a model system for induction of neuronal differentiation. PC12 cells possess specific receptors for BSF-2. The BSF-2-stimulated PC12 cells expressed the c-fos proto-oncogene transiently, and they began to change morphologically to neurite-extending cells after several days. The number of voltage-dependent Na
+
channels was also increased.
In the study of gas chromatography, it has been found that, by increasing the column temperature systematically during a run, mixtures with wide boiling point ranges can be adequately separated. The ...column, a spiral-wound type, was fixed on a heating plate, and its temperature was programmed electrically. The power of the heater coil was controlled by a thermistor type temperature detector that was situated on the heater plate and by an electronic circuit with a motor driven variable resistor with which the scheduled linear column temperature rise was possible. For decreasing the base line drift caused by the temperature rise of the column, the apparatus was modified as follows: (1) The thermal conductivity cell which was kept in a thermostat was maintained at a certain temperature higher than the maximum of the programmed temperature. (2) The carrier gas flow of the reference side had a packed column, similar to the chromatographic one, as a restriction. By these modifications, the base line drift was about 0.05 mV/40 min. The analyses of city gases and light oils are described and compared with the usual method.
Normal values of IgG subclasses in the serum were measured by the specific monoclonal antibody-based ELISA technique with a Japanese healthy adult population (840 individuals comprising 306 male and ...534 female) in their 2nd to 8th decade. The mean IgG 1 concentration in this population gradually increased linearily with increasing age although the mean levels of IgG 2, IgG 3 and IgG 4 showed no age-related significant variations. The percentages of individual IgG subclasses in the total IgG amount (as the sum of the four subclasses) revealed that the IgG 3 alone increased slightly with age. Possible differences in the percent composition of the IgG subclasses were sought between this population and a non-Japanese US healthy adult population. The percentages of IgG 1 and IgG 3 were approximately 8% and 2% lower but the IgG 2 was approximately 10% higher in the Japanese population than in the US population, with no significant difference in the IgG 4 between these populations.
In the study of gas chromatography, it has been found that, by increasing the column temperature systematically during a run, mixtures with wide boiling point ranges can be adequately separated. The ...column, a spiral-wound type, was fixed on a heating plate, and its temperature was programmed electrically. The power of the heater coil was controlled by a thermistor type temperature detector that was situated on the heater plate and by an electronic circuit with a motor driven variable resistor with which the scheduled linear column temperature rise was possible. For decreasing the base line drift caused by the temperature rise of the column, the apparatus was modified as follows: (1) The thermal conductivity cell which was kept in a thermostat was maintained at a certain temperature higher than the maximum of the programmed temperature. (2) The carrier gas flow of the reference side had a packed column, similar to the chromatographic one, as a restriction. By these modifications, the base line drift was about 0.05 mV/40 min. The analyses of city gases and light oils are described and compared with the usual method.
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