Increase of β-Fructofuranosidase Content in Tomato Fruit during the Ripening Process

β-Chloro-l-alanine was catalytically converted to pyruvate, ammonia and chloride by α-aminoisobutyrate (AIB) decomposing enzyme (α, β elimination), which was synchronously inactivated. There was a linear relationship between α, β elimination and inactivation. With apoenzyme, neither α, β elimination nor inactivation occurred. These facts suggest that α, β elimination is dependent on pyridoxal 5′-phosphate, and inactivation cooperates with α, β elimination (syncatalytic inactivation). But it seemed that d-form of β-chloroalanine was not a substrate for AIB decomposing enzyme, because just half amount of β-chloro-dl-alanine was decomposed to pyruvate by the enzyme.

An identical active site for each of following three reactions were shown by the fact that AIB decomposing activity, transamination activity and α, β elimination activity were lost in parallel. From a kinetic study, the affinity of the enzyme toward β-chloro-l-alanine was shown to be higher than that toward AIB or l-alanine. The turnover number, about 8,000, of α, β elimination during the inactivation of one mol of the enzyme was much larger than that of d-amino acid transaminase or alanine racemase.     

Intrapleural application of natural IFN alpha in breast cancer patients with pleural carcinomatosis. Monitoring of immunotherapy by assaying serum interferon levels.

For resistant local recurrence, e.g. in breast cancer, or metastatic spread, local infiltration of IFN may be an interesting new approach. The aim of this study was to find out if intrapleurally administered interferon, in breast cancer patients with pleural carcinomatosis, can cause measurable serum concentrations and how soon after administration. Serum IFN concentrations were compared with those in the pleural fluid, and correlated with the presence of malignant cells in the pleural fluid. To uncover possible rhythmicity of serum interferon levels and its relationship to the timing of therapy, natural leukocyte interferon was administered intrapleurally at 10 a.m. Data on pharmacokinetics were obtained from blood samples drawn at -2, 0, 2, 8, 14, 22 and 46 h during the course of treatment. In contrast to our previous observations in healthy volunteers, levels of serum IFN before therapy had no circadian rhythmicity. Daily pharmacokinetic profile of individual patients on interferon therapy has shown that serum IFN peaks 8 h after intrapleurally administered IFN alpha. The peak depended on frequency and number of applied doses. During treatment with IFN alpha, malignant cells degenerated and finally disappeared from pleural fluid. At the same time reactive cells appeared. This effect is rather uniformly observed, but varies in degree. The number of patients is too small, however, to permit conclusions in regard to correlation of this clinical effect and the levels of serum IFN alpha.     

Messages on small RNA duplexes in plants

Journal of Plant Research - Small RNA-mediated gene silencing encompasses diverse developmental events, stress responses, defense against pathogens, and maintenance of genome integrity. Extensive...     

Immunological properties of β-fructofuranosidase from ripening tomato fruit

The amount of tomato fruit β-fructofuranosidase extractable from the cell walls during ripening parallelled the changes in activity of the enzyme. Using the techniques of radioimmunoassay, double immunodiffusion analysis and immunotitration, no differences in immunological properties of β-fructofuranosidase between the various stages of fruit ripening were detected.