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61.
62.
Bettina Schmidt Thomas Tradler Jens-U. Rahfeld Birgit Ludwig Bunty Jain Karlheinz Mann K. Peter Rücknagel Bernhard Janowski Angelika Schierhorn Gerhard Küllertz Jörg Hacker Gunter Fischer 《Molecular microbiology》1996,21(6):1147-1160
Legionella pneumophila is the causative agent of a severe form of pneumonia in humans (Legionnaires’disease). A major virulence factor, the Mip protein (FK506-binding protein, FKBP25mem), belongs to the enzyme family of peptidyl-prolyl cis/trans isomerases (PPIases). Here we show that L. pneumophila Philadelphia I possesses an additional cytoplasmic PPiase at a level of enzyme activity comparable to that of FKBP25mem. The N-terminal amino acid sequence of the purified protein was obtained by Edman degradation and showed that the protein is a member of the cyclophilin family of PPIases. The Icy gene (Legionella cycophn) was cloned and sequenced. It encodes a putative 164-amino-acid protein with a molecular mass of 17 968 Da called L. pneumophila cyclophilin 18 (L. p. Cyp18). Amino acid sequence comparison displays considerable similarity to the cytoplasmic and the periplasmic cyclophilins of Escherichia coll with 60.5% and 51.5% identity, respectively. The substrate specificity and inhibition by cyclosporin A revealed a pattern that is typically found for other bacterial cyclophilins. An L. pneumophila Cyp18 derivative with a 19-amino-acid polypeptide extension including a 6-histi-dine tag and an enterokinase cleavage site exhibits 相似文献
63.
64.
Androgen Ablation Leads to an Upregulation and Intranuclear Accumulation of Deoxyribonuclease I in Rat Prostate Epithelial Cells Paralleling Their Apoptotic Elimination 总被引:1,自引:0,他引:1 下载免费PDF全文
65.
Stefanie Possekel Anne Lombes Helene Ogier de Baulny Marie-Arnelle Cheval Michel Fardeau Bernhard Kadenbach Norma B. Romero 《Histochemistry and cell biology》1995,103(1):59-68
Despite the demonstration of a clear biochemical defect, the genetic alterations causing childhood forms of cytochromec oxidase (COX) deficiency remain unknown. The double genetic origin (nuclear and mitochondrial DNA), and the complexity of COX enzyme structure and regulation, indicate the need for genetic iinvestigations of the molecular structure of individual COX subunits. In the present study a new monoclonal antibody, which reacts exclusively with heart-type human COX subunit VIIa (VIIa-H), and other monoclonal antibodies against human COX subunits, were used in the immunohistochemical analysis of skeletal muscle from children with different forms of mitochondrial myopathy with COX deficiency. By immunohistochemical investigation a normal reaction was seenn with antibodies to COX subunits IV, Va+Vb, and VIa+VIc in all four cases, and in two cases with antibodies to COX VIIa-H and VIIa+VIIb. In muscle from a fatal infantile case with cardiac and skeletal muscle involvement, no immunohistochemical reaction was seen with the monoclonal antibody against the tissue-specific subunit VIIa-H. In muscle from an 11-year-old boy with exclusive muscular symptoms and signs, immunohistological reactions were absent with COX subunit VIIa-H and COX subunits VIIa+VIIb, and slightly decreased with COX subunit II, thus demonstrating a different molecular mechanism in each case. It is concluded that the molecular basis of COX deficiency in childhood may vary greatly between patients. 相似文献
66.
tRNA genes and pathogenicity islands: influence on virulence and metabolic properties of uropathogenic Escherichia coli 总被引:13,自引:2,他引:11
67.
Bernhard Schink 《Archives of microbiology》1984,137(3):250-255
A new mesophilic, sporeforming, strictly anaerboic bacterium was isolated form enrichments with 2,3-butanediol as sole substrate and pasteurized freshwater sediment as inoculum. Cells were large, motile rods, and elliptical spores were formed subterminally or centrally. They stained Gram-negative, but no typical outer membrane layer could be observed by electron microscopy of ultrathin sections. 2,3-Butanediol, acetoin, fructose, glucose, sucrose, xylose, malate and citrate served as substrates and were completely converted to acetate with concomitant reduction of carbon dioxide. Growth on glucose (t
dmin=1.4 h) was faster than on butanediol (t
dmin=3.6 h). No growth occurred on hydrogen/carbon dioxide, on formate or on methanol. The guanine plus cytosine content of the DNA was 29.1%. The new isolate is described as a new species, Clostridium magnum sp. nov. 相似文献
68.
J Hüttermann E Haindl G Schmidt W A Bernhard 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1977,32(5):431-438
X-irradiation at 77 K and subsequent warming to 150 K of single crystals of 5-chloro-and 5-bromodeoxyuridine produces a radical located at position C5' of the deoxyribose moiety. The radical exhibits identical spectral properties in both crystal systems. It is characterized by interaction of the unpaired electron with an alpha-proton(-17-0, -8-7, -33-7G), a beta-proton (18-6, 21-3, 17-5 G) as well as an OH-proton (4-8, 7-9, 12-8 G). The principal values of the g-tensor are 2-0034, 2-0049 and 2-0042. The spectral parameters are discussed in relation to those of the same or similar radicals in other nucleosides (-tides). 相似文献
69.
Helmut Klocker Bernhard Auer Helmut J. Burtscher Monica Hirsch-Kauffmann Manfred Schweiger 《Molecular & general genetics : MGG》1982,188(2):309-312
Summary The UV photoproduct, thymine dimer (
), is excorporated with a remarkably low rate from the DNA of human fibroblasts grown in cell culture. An UV dose of 18 J/m2 creates 0.045%
(related to thymine). Within the first two days of repair logarithmically growing and quiescent fibroblasts exhibit the same repair rates; thereafter, the proportion of
is lower in growing cells due to recovery of DNA replication. Only about 50% of the lesions are excised within 24 h. In quiescent cells, 13% of the thymine dimers originally present can be detected as late as a week after UV-irradiation. Two distinct first-order rate constants indicate that approximately half of the dimers are less accessible to repair. Repair measured by the nucleoid decondensation technique corresponds to the faster repair rate, whereas the slow repair rate cannot be detected by this method. Saturation of repair is found beyond 27 J/m2. The remarkably slow rate of excision indicates that thymine dimers are not lethal lesions in human fibroblasts. 相似文献
70.
Summary The generally accepted concept that dorsoventral flatness and/or small size of benthic stream invertebrates staying on the surface of the bottom substratum allows a current-sheltered life in the boundary layer (Ambühl 1959) is checked by means of the new technique of Laser Doppler Anemometry (LDA). With LDA measurement of flow can be done nearly punctually without any mechanical disturbance. Mapping the current velocities around the body of Ecdyonurus cf. venosus (Insecta, Ephemeroptera) and Ancylus fluviatilis (Gastropoda) gives evidence that boundary layer separation occurs above the animals' bodies. Our results indicate that the velocities around the body of benthic stream invertebrates and probably the forces acting on them are much more complicate than is suggested by the currently accepted boundary layer concept. 相似文献