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331.
A carboxypeptidase of St. griseus K-1 (CPase S) was found to possess the specificities of both mammalian pancreatic CPase A and B. Three adsorbents for affinity chromatography were prepared by coupling l-Leu, d-Leu, and d-Arg with CH-Sepharose 4B. d-Arg-CH-Sepharose and l-Leu-CH-Sepharose retained the purified CPase S but d-Leu-CH-Sepharose did not. The activities of CPase S toward CGL and BGA were eluted in the same position. CPase S migrated as a single band on polyacrylamide gel electrophoresis and the two activities were both extracted from this band on the gel. 相似文献
332.
In many species that have internal fertilization, seminal flow includes various elements and materials in addition to the
fertilizing sperm. The roles of these components are unknown. One hypothesis is that they are nutritional gifts to the female
as a paternal investment. We made game theoretical models from the point of view of sperm competition among males and examined
this hypothesis. The evolutionary stable strategy (ESS) of the models showed that (1) when multiple mating in the female is
relatively low, gifts in seminal flow or other types of gift may evolve, at least, a male does not resist a female digesting
his sperm; and (2) the ratio of nutritional gift rapidly decreases to zero with the probability or frequency of multiple mating
in the female. Hence, we concluded that nutritional gifts in seminal flow can exist only in species in which sperm competition
among males is rare. Furthermore, we concluded that if an element or material eminently decreases when sperm competition becomes
intense, it may be a gift as a paternal investment; if not, other hypotheses concerned with more agonistic roles are more
feasible.
Received: November 6, 2000 / Accepted: January 10, 2001 相似文献
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Mariko Nakamura Hidechika Okada Hiroyuki Sasaki Kiyotsugu Yoshida Minori Kamada Noriko Okada Masaki Terada Tsuneya Ohno 《Microbiology and immunology》1996,40(8):561-567
Previous studies have demonstrated that the murine monoclonal antibody (MoAb) NM-01 activates the human complement classical pathway resulting in lysis of human immunodeficiency virus (HIV). The present study was performed to determine the availability of the V3-loop of gp120 relative to the complement regulatory proteins, CD55 (DAF) and CD59 (HRF20) molecules on HIV. The results demonstrate that CD55 and CD59 exist on HIV virions, along with gp120 molecules. These findings suggest that activation of human complement on free viral particles is induced by MoAb NM-01 and that this occurs regardless of the presence of CD55 and CD59 molecules. The destruction of viral particles was demonstrated by a decrease in infectivity. The involvement of human complement in this process was confirmed with an immunoelectron microscopy technique by the presence of a human C9 to prove membrane attack complex (MAC). The results indicate that NM-01 can induce complement activation because of the ratios of CD55 and CD59 to gp120 molecules on HIV virions. The availability of the gp120 V3 domain on the virion is sufficient for binding of NM-01 and thereby the formation of MAC that results in virolysis. 相似文献
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The species composition and density of seeds in the soil of a climax evergeen oak forest in the Kasugayama Forest Reserve,
Nara, Japan were studied by directly extracting seeds from soil samples and using soil samples in planting boxes as the basis
of germination tests.
A total of 33 species were identified from all seeds collected in 6 stands: 11 evergreen broadleaf, 15 deciduous broadleaf,
2 coniferous, 2 liana, 1 herb, and 2 grass species. Species producing sap fruits and dry fruits accounted for 60% and 40%
of the total number of species, respectively. The species composition of all the seeds was independent of the species composition
of the forest vegetation. The mean density of the seeds was 22,134 seeds/m2·5 cm.Eurya japonica, of which seeds were found in all soil samples, was the most abundant species, followed byCryptomeria japonica, Ilex micrococca, andBoehmeria longispica. Pioneer species such asMallotus japonicus, Zanthoxylum ailanthoides, andAralia elata were found in all soil samples in spite of the paucity of adult trees in the forest. Seeds of evergreen oaks were relatively
aboundant but no viable seeds were found. ViableE. japonica, I. micrococca, Symplocos prunifolia, andB. longispica seeds were abundant. 相似文献
340.
Transfer of heme from mitochondria in rat liver cells 总被引:7,自引:0,他引:7