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151.
The differential effects of polyamines on the activity of AMP deaminase isozyme A (from rat muscle) and isozyme B (from rat liver) are reported. Polyamines activate isozyme B but inhibit isozyme A. 相似文献
152.
Akio Murakami 《Radiation and environmental biophysics》1976,13(3):187-195
Summary The physical induction of recombinational events has been studied in the female silkworm (Bombyx mori), in which crossing-over does not normally occur. Female silkworms heterozygous in the trans type of two egg-color genes,pe (V-0.0) andre (V-31.7), received a single dose of X-rays (1000 R) at various developmental stages. Then they were crossed to marked males homozygous for both genes. The results indicated that X-rays increase the occurrence of recombinational events in silkworm females from first instar larvae to late stage pupae. The spontaneous frequency of exchange type recombinants in the control series was 2.5 x 10–5, while after irradiation the frequency of these recombinants was up to 38.8 x10–5. The sensitive stage to X-ray-induced recombinational events was late stage larvae from fourth to fifth instar. Exchange (cross-over) type recombinants were about three times more frequent than interchange types among the 122 recombinants recovered. The biological significance of the present finding is discussed. 相似文献
153.
The activities of the digestive enzymes, maltase [EC 3.2.1.20], sucrase [EC 3.2.1.26], trehalase [EC 3.2.1.28], Leucine aminopeptidase [EC 3.4.11.1], and alkaline phosphatase [EC 3.1.3.1] were measured in various regions of the small intestine of rats. The activities of all these enzymes were much higher in the jejunum than in the ileum, and in the distal regions of the ileum no sucrase, trehalase or alkaline phosphatase activity was detected. In the jejunum, the activities of all the enzymes tested exhibited clear circadian variations with the highest activity at 0000-0400 h and the lowest at 1200 h when the rats were fed ad libitum. In the ileum, maltase and sucrase also exhibited circadian variations, but the amplitude of the rhythm was smaller than that in the jejenum. Trehalase and alkaline phosphatase did not show any circadian variation in the ileum. Leucine aminopeptidase showed a circadian variation in the ileum with the same amplitude as in the jejunum. The phase of the circadian variations shifted about half a day when the rats were fed in the daytime, but the amplitude of the rhythm did not change. 相似文献
154.
The xanthurenic acid-insulin complex was found to have similar immunological properties to native Zn-insulin. This complex showed less hormonal activity on glucose metabolism in adipose tissue than native An-insulin, but its activity was increased by addition of Zn2+ ions. 相似文献
155.
Antisera to the LP and SP34 strains of polyoma virus have been prepared and their reactions with purified virions studied by double diffusion in agar and direct assay of antibody binding. One or more common antigenic determinants appear on the capsids of both strains. The form of this determinant varies slightly on each of the strains tested. The SP34 strain also carries its own strain-specific antigenic determinant. Both strains of virus were able to bind 150 anti-LP IgG3 molecules per virion and 50 anti-SP IgG molecules per virion. The slow rate of dissociation of bound IgG antibody (kdissociation = 2 × 10−6 s−1), and the rapid rate of antibody binding (kdissociation = 2 × 107m−1 s−1), suggest that IgG antibody is bound to the capsid surface through two antigen-antibody bonds. 50 anti-SP IgG molecules per capsid, divalently bound, completely inhibit the binding of 150 anti-LP IgG molecules, and vice versa. Consideration of the symmetry and molecular dimensions of the IgG molecule and the polyoma virus capsid leads to a model of the divalent interaction of IgG antibody with the common antigenic determinant(s). In this model, one species of antibody binds divalently to opposed subunits of a hexamer morphological unit. The other species of antibody binds divalently to the subunits on either side of the point of tangency of any two morphological units. 相似文献
156.
157.
A Murakami S Nagahara H Uematsu K Otoi T Haruna H Ide K Makino 《Nucleic acids symposium series》1992,(27):123-124
In order to study interaction of various types of labeled antisense DNAs were prepared. Fluorescein and 2,2,6,6-tetramethypiperidine-N-oxyl were the label molecules, which were introduced to 5'-end of oligonucleotides and their analogs. Interactions of labeled antisense DNAs with nucleic acids or proteins such as HSA, HIG and TF, were studied by UV, fluorescence depolarization spectroscopy, and ESR spectroscopy. Hybrid formation of antisense DNAs with oligonucleotides in solution could be monitored by the increase in fluorescence anisotropy (r) and by intensity change in ESR spectra. When phosphorothioate type antisense molecules anchoring fluorescein (F-OPT) were mixed with proteins, r drastically increased, whereas ODN slightly increased. These results suggest that OPTs have much more affinity for proteins than ODNs. 相似文献
158.
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160.