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1.
Ribonuclease A behaves anomalously on polyacrylamide gel electrophoresis at acid pH. The distance traveled by the protein is a function of the amount of enzyme added at the lower range of detectable activity (10 pg to 100 ng). Addition of myoglobin (1 mg/ml) abolishes the anomaly. The observations are consistent with the known affinity of RNase for anions. Caution is warranted in the interpretation of apparent electrophoretic variants of RNase observed at low concentrations of enzyme. 相似文献
2.
J. Hofsteenge A. Vicentini O. Zelenko 《Cellular and molecular life sciences : CMLS》1998,54(8):804-810
The structural and enzymatic properties of RNase 4 are reviewed. This RNase shows a much higher interspecies similarity (approximately
90%) than the other members of the RNase A superfamily. The enzyme is ubiquitous, with the highest amounts present in liver
and lung. Its unique uridine specificity results from alterations in and around the pyrimidine-binding site. In particular,
the shortened C-terminus and the side chains of Phe-42, Asp-80 and Arg-101 appear to be involved. RNase 4 binds tightly to
the intracellular RNase inhibitor, with a K
d of 4 × 10−15 M. 相似文献
3.
Helga Schwarzkopf 《Cellular and molecular life sciences : CMLS》1968,24(11):1110-1110
Summary Decreased reactivation of inactivated RNase by microsomes from a hepatoma as compared to normal liver was observed and is described in more detail. This hampered reactivation of enzymes in general might be responsible for other enzyme deletions in tumours. 相似文献
4.
A. Vervoort 《Cellular and molecular life sciences : CMLS》1979,35(4):479-480
Summary The diploid DNA content ofPhractolaemus ansorgei spinosus (Phractolaemidae) is estimated by Feulgen cytophotometry at 3 pg. The karyotype has 28 chromosomes and 54 chromosome arms; it significantly resembles the karyotype ofChanos chanos (Chanidae).Research supported by the Division of Human Genetics, K. U. Leuven, Belgium. The Zairian ONRD permitted a stay at IRSAC-Mabali. The Department of Human Genetics, University of Amsterdam, Netherlands, provided laboratorium facilities for cytophotometric analysis. I thank J. Bylsma, M. Kibishwa, F. Koperdraad and H. Van den Berghe for advice. 相似文献
5.
Mattijssen S Hinson ER Onnekink C Hermanns P Zabel B Cresswell P Pruijn GJ 《Cellular and molecular life sciences : CMLS》2011,68(14):2469-2480
RNase MRP is a conserved endoribonuclease, in humans consisting of a 267-nucleotide RNA associated with 7–10 proteins. Mutations
in its RNA component lead to several autosomal recessive skeletal dysplasias, including cartilage-hair hypoplasia (CHH). Because
the known substrates of mammalian RNase MRP, pre-ribosomal RNA, and RNA involved in mitochondrial DNA replication are not
likely involved in CHH, we analyzed the effects of RNase MRP (and the structurally related RNase P) depletion on mRNAs using
DNA microarrays. We confirmed the upregulation of the interferon-inducible viperin mRNA by RNAi experiments and this appeared
to be independent of the interferon response. We detected two cleavage sites for RNase MRP/RNase P in the coding sequence
of viperin mRNA. This is the first study providing direct evidence for the cleavage of a mRNA by RNase MRP/RNase P in human
cells. Implications for the involvement in the pathophysiology of CHH are discussed. 相似文献
6.
7.
H. F. Rosenberg 《Cellular and molecular life sciences : CMLS》1998,54(8):795-803
The eosinophil ribonucleases, eosinophil-derived neurotoxin (EDN/RNase 2) and eosinophil cationic protein (ECP/RNase 3) are
two closely related proteins with intriguing functional and evolutionary properties. While both EDN and ECP maintain the structural
and catalytic residues typical of the RNase A superfamily, the role of ribonuclease activity in the physiologic function of
these proteins remains unclear. The biochemistry and physiology of EDN, ECP and the recently discovered ribonuclease k6 (RNase
6) will be reviewed in this chapter. 相似文献
8.
9.
A. Vervoort 《Cellular and molecular life sciences : CMLS》1980,36(6):646-647
Summary
Calamoichthys calabaricus, Polypterus palmas, P. weeksii, P. delhezi andP. ornatipinnis have the same amount of DNA per erythrocyte nucleus. The karyotype ofP. weeksii has 38 chromosomes and differs from the karyotypes of the other species, all with 36 chromosomes, by a Robertsonian chromosomal rearrangement. The karyotype condition is regarded as derived for vertebrates.Research supported by the Division of Human Genetics, K.U. Leuven, Belgium and the UNAZA, campus Kinshasa, Zaire. The Department of Human Genetics, University of Amsterdam, Netherlands, provided facilities for cytophotometry. 相似文献
10.
Penicillin stimulates the formation of ribonuclease in embryoless rice (Oryza sativa L.) endosperm and enhances gibberelin-induced response. Penicillin-induced RNase production is completely inhibited by abscisic acid. 相似文献
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13.
Localization and analysis of nonpolar regions in onconase 总被引:1,自引:0,他引:1
Kolbanovskaya EY Terwisscha van Scheltinga AC Mukhortov VG Ardelt W Beintema JJ Karpeisky MY 《Cellular and molecular life sciences : CMLS》2000,57(8-9):1306-1316
A detailed analysis of the composition and properties of hydrophobic nuclei and microclusters has been carried out for onconase. Two main hydrophobic nuclei in the onconase structure were detected. Their composition and shape were found to be very similar to those of RNase A, in accordance with the predictions made. The nuclei in onconase are more compact, the side-chain atoms of residues included in the nuclei in onconase form more contacts with the environment than in RNase A. The hydrophobic nuclei should be considered as individual structural units along with elements of the secondary structure. Differences in composition and conformation of exposed loops between onconase and RNase A were found. The additional hydrophobic clusters attached to the nuclei in onconase might be involved in the fixation of an appropriate conformation of site(s) for manifestation of the biological activity of onconase. A comparison of amphibian representatives of the RNase A superfamily was also made. The results obtained suggest that the availability of nonpolar residues in established key positions of amino acid sequences determines the characteristic fold of homologous proteins and the structure of the active site cleft. 相似文献
14.
S. Ishikawa M. O. Cheung E. F. Gilbert H. J. Bruyère Jr 《Cellular and molecular life sciences : CMLS》1979,35(1):92-93
Summary The effect of acetylsalicyclic acid upon the ducti arteriosi of the embryonic chick was studied. A spectrum of gross malformations and histological findings associated with premature closure of the right ductus arteriosus is presented.This study was supported by grant No. HL18050, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland. The authors wish to extend their appreciation to John M. Opitz, University of Wisconsin Department of Genetics, for his generous support. This report was presented in part at the Fiftieth Scientific Sessions, American Heart Association Meetings, Miami, Florida, November 1977. 相似文献
15.
M. C. Lechner M. C. Duque Magalhães 《Cellular and molecular life sciences : CMLS》1973,29(12):1479-1480
Résumé Les activités de la RNase ont été déterminées dans le sérum sanguin de 15 espèces de Vertebrés appartenant aux trois groupes définis parBarnard. Les résultats obtenus montrent que les activités de la RNase n'offrent pas de différences (exception faite pour le cobaye), ce qui exclut l'existence d'une relation directe, simple entre RNase pancréatique et sérique. On relève l'interêt phylogénétique de ces protéines et de l'origine de la RNase sérique. 相似文献
16.
A. Vervoort 《Cellular and molecular life sciences : CMLS》1980,36(3):294-296
Summary Comparative DNA values obtained by Feulgen cytophotometry for 3 species ofProtopterus, as well as karyotype analysis, show the existence of a diploid-tetraploid relationship within the genusProtopterus.Research supported by the Division of Human Genetics, K. U. Leuven, Belgium, and by the Université Nationale du Zaire, campus Kinshasa, Zaire. The Department of Human Genetics, University of Amsterdam. The Netherlands, provided laboratory facilities for cytophotometric analysis. I thank J. Bylsma, A. Debont, F. Koperdraad and H. Van den Berghe for advice, R. Ruysschaert and G. Warmoes for hospitality and technical assistance and T. Mohsen for the generous gift ofP. annectens from Senegal. 相似文献
17.
G. Yasuzumi 《Cellular and molecular life sciences : CMLS》1957,13(8):313-314
Zusammenfassung An ultradünnen Schnittpr?paraten von Speicheldrüsenchromosomen (Drosophila melanogaster) und an entsprechenden Quetschpr?paraten (Drosophila virilis) wurde elektronenmikroskopisch festgestellt: Die Chromomeren und Chromonemata bestehen aus Filamenten mit Schraubenwindungen
vom ?paran?mischen? Typus. Es ist wahrscheinlich, dass die Windungen der beiden Filamente in der entgegengesetzten Richtung
ranken.
The substance of this article was present in 1956 at the International Genetics Symposia in Tokyo. 相似文献
The substance of this article was present in 1956 at the International Genetics Symposia in Tokyo. 相似文献
18.
Summary By means of hungry Triatomid bugs, samples of blood (40–200l) can be obtained from small mammals, such as bats, without causing any harm to the animals. The blood can be extracted from the gaster of the bug immediately after the bug has finished sucking. The method was successfully used for measuring the energy budget by the doubly labeled water method, and for obtaining material for lymphocyte cultures, and may prove useful in other fields, too.M. Volleth is very much obliged to Prof. Dr R. A. Pfeiffer for giving her the opportunity to work at the Institute of Human Genetics. 相似文献
19.
O. Mayo G. R. Bishop T. W. Hancock 《Cellular and molecular life sciences : CMLS》1977,33(8):1024-1025
Summary Heritability is well known to be a poor indicator of genetical variation in fitness. We show here that it is also an inadequqte measure of genetical variation in fecundity.Acknowledgment. Part of this work was carried out while one of us (O. M.) was on sabbatical leave in the Genetics Laboratory, Oxford University. We thank Dr G. J. Thomson for stimulating discussion. 相似文献
20.
Zusammenfassung Es scheint, dass DNase und RNase bei der photosynthetischen Fixierung des CO2 verschiedene und komplizierte Wirkung ausüben. Die Saccharaose-Synthese wird durch die Behandlung mit DNase und RNase deutlich vermindert. 相似文献