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1.
Immunological cross-reactivity of L-gulonolactone oxidase of different species (rat, chicken, and bullfrog) was tested by the Ouchterlony technique. Antiserum directed against the enzyme from chicken kidney reacted with rat liver enzyme as well as with bullfrog kidney enzyme. This finding suggests that there is, at least partly, sequence homology among the enzyme from species belonging to the three classes, Mammalian, Aves, and Amphibia.  相似文献   

2.
Summary Immunological cross-reactivity of L-gulonolactone oxidase of different species (rat, chicken, and bullfrog) was tested by the Ouchterlony technique. Antiserum directed against the enzyme from chicken kidney reacted with rat liver enzyme as well as with bullfrog kidney enzyme. This finding suggests that there is, at least partly, sequence homology among the enzymes from species belonging to the three classes, Mammalia, Aves, and Amphibia.  相似文献   

3.
Summary An enzyme that hydrolyzes acetylcholine is present in the dried venoms of 19 species of theColubridae (9 genera), but not in the venoms of more than 20 species of theViperidae (7 genera). The enzyme behaves like the e-Cholinesterase of the mammalian tissues.  相似文献   

4.
125 species were investigated for rutinase. A high enzyme activity was found only in a few genera: Fagopyrum, Rhamnus, Berchemia, Sophora, Datisca and Danae. Lower activity was detected in several Lichens (Parmeliaceae) and diverse plants but is lacking in some specimens. In a number of species containing 3- or 7-rutinosides, no enzyme able to hydrolyse the latter seems to be present.  相似文献   

5.
Inhibitory effects of three peptidyl phenylalaninals on fertilization and on chymotrypsin-like enzyme activity of sperm in three species of ascidians were examined. The results suggest that a sperm chymotrypsin-like enzyme is indispensable for the fertilization in each of the ascidians, and that these enzymes have different susceptibilities to inhibitors.  相似文献   

6.
Summary Kluyvera, a proposed genus formerly known as Enteric group 8, was found to have similar enzyme profiles among the present 3 groups.Kluyvera species group 3 showed the most heterogeneous enzyme reactions.To whom reprint requests should be addressed.  相似文献   

7.
Summary The guinea-pig,Cavia porcellus, is unusual in possessing plasma L-asparaginase, an enzyme with anti-tumor activity. 21 additional species have been examined as to the presence of this enzyme: the results confirm and extend its remarkably limited species distribution.This work was supported in part by grant GM/CA 25378 from the National Institute of General Medical Sciences, National Institutes of Health.We are grateful to dr Hanna Hensch, Philadelphia Zoological Garden, and Ms Joan Whitla and Dr Richard J. Montali, National Zoological Park/Smithsonian Institution, for samples of frozen serum.To whom correspondence should be addressed.  相似文献   

8.
Summary An analysis of allozyme data from numerous sets of related vertebrate andDrosophila species shows that species divergence does not generally seem to be accompanied by an overall increase or decrease in enzyme charge. The 2 significant results came from vertebrate inter-generic comparisons.  相似文献   

9.
Summary Monkey red cells were chosen as controls in tests of human red cell galactose-l-phosphate uridyl transferase, after comparing activities and isozyme patterns of the enzyme from several domestic or laboratory-bred species.  相似文献   

10.
Summary Inhibitory effects of three peptidyl phenylalaninals on fertilization and on chymotrypsin-like enzyme activity of sperm in three species of ascidians were examined. The results suggest that a sperm chymotrypsin-like enzyme is indispensable for the fertilization in each of the ascidians, and that these enzymes have different susceptibilities to inhibitors.12 November 1986Acknowledgments. We are indebted to Dr M. Hoshi of Tokyo Institute of Technology for his helpful discussion. This work was supportd by a Grant-in-Aid from the Ministry of Education, Science and Culture of Japan.  相似文献   

11.
Regulation and termination of NADPH oxidase activity   总被引:11,自引:0,他引:11  
NADPH oxidase of phagocytes plays a crucial role in host defense by producing reactive oxygen species (ROS) that are intended to kill invading microbes. Many other cells produce ROS for signaling purposes. The respiratory burst oxidase in human neutrophils is the main but not exclusive subject of this review, because it is archetypical and has been studied most extensively. The activity of this enzyme must be controlled in phagocytes to prevent collateral damage, and in non-phagocytic cells to perform its signaling role. With many stimuli, NADPH oxidase activity is transient. Various forms of evidence indicate that sustained NADPH oxidase activity requires continuous renewal of the enzyme complex, without which rapid deactivation occurs. This review considers mechanisms that have been proposed to terminate the phagocyte respiratory burst. Changes in the phosphorylation state of p47(phox) and in the species of nucleotide bound to Rac seem to be the dominant factors in deactivation.  相似文献   

12.
Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.  相似文献   

13.
Chromate reduction in Streptomyces   总被引:2,自引:0,他引:2  
S Das  A L Chandra 《Experientia》1990,46(7):731-733
Streptomyces species 3M grew in peptone yeast extract medium with 1000 micrograms/ml K2Cr2O7. Incubation of the chromate with different cell fractions in the presence of NADH and NADPH resulted in a decrease of Cr6+ in the reaction mixture. The level of Cr6+ was reduced by 82.7% by a particulate cell fraction obtained by centrifugation at 105,000 x g for 1 h, in the presence of NADH. The reducing enzyme was associated with this cell fraction. The enzyme was constitutive and reduced Cr6+ to Cr3+.  相似文献   

14.
Summary Incubation of human, canine or rabbit MM creatine kinase with carboxypeptidase-N or B resulted in the production of 2 additional enzyme forms with increased anodal migration on polyacrylamide gels. The C-terminal amino acid of tissue MM creatine kinase from all 3 species was shown to be lysine, a specific substrate for carboxypeptidase-N and B.  相似文献   

15.
M B Perryman  J D Knell  R Roberts 《Experientia》1984,40(11):1275-1277
Incubation of human, canine or rabbit MM creatine kinase with carboxypeptidase-N or B resulted in the production of 2 additional enzyme forms with increased anodal migration on polyacrylamide gels. The C-terminal amino acid of tissue MM creatine kinase from all 3 species was shown to be lysine, a specific substrate for carboxypeptidase-N and B.  相似文献   

16.
Enzyme membranes can be activated or inhibited by applying continuous or alternating electrical fields. The field can modify the transport or reaction term of the transport-reaction by action on the displacement of charged species including those giving pH effects or inducing volume flows. A first experimental example is given: the progressive supression of the inhibition of hexokinase by the product when increasing alternating fields are applied. In the same way the apparent optimal pH approaches that of the soluble enzyme. In addition to its theoretical and practical implications electrical regulation can lead to the monitoring of enzyme reaction-driven mechanochemical fibers.  相似文献   

17.
Buffalo sperm acrosome resembles its counterpart in other species, being rich in hydrolytic enzymes. Of the enzyme activities estimated, acid phosphatase, beta-N-acetylglucosaminidase and hyaluronidase were low compared to those of ram semen. However, the aryl sulphatase activity was high. GOT activity estimated in sperm preparation may not be of acrosomal origin.  相似文献   

18.
Genetic variability of D. sechellia is investigated at both mitochondrial and nuclear levels. The results reveal the existence of a single main type of mtDNA with very few variants and a very low enzyme polymorphism. This situation is consistent with the small population size of this specialized species.  相似文献   

19.
Summary The carp, Cyprinus carpio (Teleostomi), is a tetraploid species which currently expresses 52% of its duplicate enzyme loci. This level of duplicate gene expression in this cyprinid species is comparable to those observed in tetraploid Catostomidae, but higher than those in tetraploid Cobitidae.This research was supported by NSF grants GB 43995 and PCM 76-08383 to G.S.W. and by a Cell Biology Traineeship to S.D.F.We thank Suzanne Fisher and Dave Philipp for their helpful comments.  相似文献   

20.
Summary Genetic variability ofD. sechellia is investigated at both mitochondrial and nuclear levels. The results reveal the existence of a single main type of mtDNA with very few variants and a very low enzyme polymorphism. This situation is consistent with the small population size of this specialized species.  相似文献   

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