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High Base Pair Opening Rates in Tracts of GC Base Pairs

Utz Dornberger, Mikael Leijon, Hartmut Fritzsche
1999 Journal of Biological Chemistry  
Utz Dornberger, Mikael Leijon and Hartmut Fritzsche High Base Pair Opening Rates in Tracts of GC Base Pairs  ... 
doi:10.1074/jbc.274.11.6957 pmid:10066749 fatcat:gtge7ci5njhkbjguok6bwmmogm

Infrared linear dichroism of oriented DNA-ligand complexes prepared with the wet-spinning method

Hartmut Fritzsche, Allan Rupprecht, Monika Richter
1984 Nucleic Acids Research  
Oriented DNA films prepared by the wet-spinning technique have been complexed with several ligands: the anthracycline antibiotic violamycin BI, the dipeptide L-carnosine, and the oligopeptide antibiotic netropsin. The formation of the DNA-ligand complexes is accompanied by dramatic changes of the conformational flexibility of DNA. The B-A transition which occurs usually between 801 and 70* relative humidity (RH) is more or less suppressed by the ligands. Violamycin BI at a total ligand per DNA
more » ... ase pair ratio, r , of ^0.03 and L-carnosine at r ^ 1.5 inhibit the B-A transition of ^18 and ^0.25 base pairs per ligand molecule, respectively. Netropsin at r = 0.2 induces a very stable B-DNA even at rather low RH (23 4). The total hydration of this complex is significantly higher than for a drug-free DNA film. Netropsin-DNA complexes at r of 0.02 and 0.01 result in an inhibition of M5 base pairs per drug molecule with respect to the B-A transition. © IRL Pros Limited, Oxford, England. Vteloaycin BI/1 H OH BI/2 OH OH BI/S OH H
doi:10.1093/nar/12.23.9165 pmid:6096820 pmcid:PMC320446 fatcat:odblf4x5d5arzd74pdnersij6q

The formation of A-DNA in NaDNA films is suppressed by netropsin

Hartmut Fritzsche, Rolf Brandes, Allan Rupprecht, Zhiyan Song, Thomas Weidlich, David R. Kearns
1992 Nucleic Acids Research  
dichroism studies of the conformation of the sugar-phosphate backbone in NaDNA-netropsin complexes, which showed that the B-A transition is suppressed for r-values down to approximately 0.1 drug/base pair (Fritzsche  ... 
doi:10.1093/nar/20.6.1223 pmid:1313963 pmcid:PMC312162 fatcat:4avxz4yblrdxhkko7ih3rqo47i

Structure and Drug interaction of parellel-stranded DNA studies by infrared spectroscope and fluorence

Hartmut Fritzsche, Alain Akhebat, Eliane Taillandier, Karsten Rippe, Thomas M. Jovin
1993 Nucleic Acids Research  
The infrared spectra of three different 25-mer parallelstranded DNAs (ps-DNA) have been studied. We have used ps-DNAs containing either exclusively dA* dT base pairs or substitution with four dG dC base pairs and have them compared with their antiparallelstranded (aps) reference duplexes in a conventional B-DNA conformation. Significant differences have been found in the region of the thymine C =0 stretching vibrations. The parallel-stranded duplexes showed characteristic marker bands for the
more » ... = 02 and C4 = 04 carbonyl stretching vibrations of thymine at 1685 cm-1 and 1668 cm-1 , respectively, as compared to values of 1696 cm-1 and 1663 cm-1 for the antiparallel-stranded reference duplexes. The results confirm previous studies indicating that the secondary structure in parallel-stranded DNA is established by reversed Watson -Crick base pairing of dA dT with hydrogen bonds between N6H...02 and Ni...HN3. The duplex structure of the ps-DNA is much more sensitive to dehydration than that of the aps-DNA. Interaction with three drugs known to bind in the minor groove of aps-DNAnetropsin, distamycin A and Hoechst 33258 -induces shifts of the C = 0 stretching vibrations of ps-DNA even at low ratio of drug per DNA base pair. These results suggest a conformational change of the ps-DNA to optimize the DNA-drug Interaction. As demonstrated by excimer fluorescence of strands labeled with pyrene at the 5"-end, the drugs induce dissociation of the ps-DNA duplex with subsequent formation of imperfectly matched aps-DNA to allow the more favorable drug binding to aps-DNA. Similarly, attempts to form a triple helix of the type d(T)n-d(A)nd(T)n with ps-DNA failed and resulted in the dissociation of the ps-DNA duplex and reformation of a triple helix based upon an aps-DNA duplex core d(T)1o * d(A)10.
doi:10.1093/nar/21.22.5085 pmid:7504812 pmcid:PMC310621 fatcat:gdr4wrhh4bho7aprbyqf5hxzuy

Nuclear magnetic resonance study on the exchange behavior of the NH-N protons of a ribonucleic acid miniduplex

Hartmut Fritzsche, Lou Sing Kan, Paul O. P. Ts'o
1983 Biochemistry  
Again the reader is referred to our previous paper (Fritzsche et al., 1981) .  ...  A more detailed discussion is presented in our previous paper (Fritzsche et al., 1981) .  ... 
doi:10.1021/bi00271a007 pmid:6186275 fatcat:j4fdzeld7rfoddkrqpzfdzexae

Infrared linear dichroism studies of DNA-drug complexes: quantitative determination of the drug-induced restriction of the B - A transition

Hartmut Fritzsche
1994 Nucleic Acids Research  
The B -A transition of films or fibers of NaDNA occurs at a relative humidity of 75 -85%. The fraction of DNA that changed the conformation from B to A form can be determined quantitatively by infrared linear dichroism. DNA-binding drugs can 'freeze' a fraction of DNA in the B form. This fraction of DNA is in the B form and cannot be converted to A-DNA even at a reduced relative humidity of 54%. The 'freezing' potentiality of various drugs can be described by the 'freezing' index, Fl, expressed
more » ... in base pairs per added drug. Drugs with a high value of F! (more than eight base pairs per drug) were observed among both intercalating and groove-binding drugs. High values of F! imply restriction of the conformational flexibility of DNA significantly going beyond the binding site of the drug. This long-range effect of drugs on the conformational flexibility of DNA may be connected with the molecular mechanism of drug action. The freezing index F! is a new quantitative parameter of drug -DNA interaction that should be considered as a valuable tool for drug design.
doi:10.1093/nar/22.5.787 pmid:8139919 pmcid:PMC307883 fatcat:bvtpuacv6rajbf67ldcg52q3py

Towards extracting the timelike pion form factor on CLS twoflavour ensembles

Felix Erben, Jeremy Green, Daniel Mohler, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
Results are presented from an ongoing study of the ρ resonance. The focus is on CLS 2-flavour ensembles generated using O(a) improved Wilson fermions with pion masses ranging from 265 to 437 MeV. The energy levels are extracted by solving the GEVP of correlator matrices, created with the distillation approach involving ρ and ππ interpolators. The study is done in the centre-of-mass frame and several moving frames. One aim of this work is to extract the timelike pion form factor after applying
more » ... e Lüscher formalism. We therefore plan to integrate this study with the existing Mainz programme for the calculation of the hadronic vacuum polarization contribution to the muon g-2.
doi:10.1051/epjconf/201817505027 fatcat:rnmthq5b4vcgrhbp22gzf4cacm

Effect of individualized communication skills training on physicians' discussion of clinical trials in oncology: results from a randomized controlled trial

Alexander Wuensch, Tanja Goelz, Gabriele Ihorst, Darcey D. Terris, Hartmut Bertz, Juergen Bengel, Michael Wirsching, Kurt Fritzsche
2017 BMC Cancer  
Discussing randomized clinical trials (RCTs) with cancer patients is one of the most challenging communication tasks a physician faces. Only two prior Communication Skills Trainings (CSTs) focused on RCTs in oncology have been reported. Their results demonstrated the need for further improvement. We developed and evaluated an enhanced, individually-tailored CST focused on improving physicians' communication during discussions of RCTs. Methods: The CST focused on personal learning goals derived
more » ... rom video pre-assessment that were addressed in a 1.5-day group workshop and one-on-one coaching sessions. Forty physicians were recruited and randomly assigned to intervention and control groups. Video-recorded standardized consultations with actor-patients were utilized. As a primary outcome (1), training success was evaluated by blinded raters using a previously developed checklist. Change in checklist items was evaluated between pre-and post-training assessment and compared against control group results. As a secondary outcome (2), the physicians' feeling of confidence was assessed by a questionnaire. Results: (1) Significant improvements in the intervention group were observed for the score on all items (p = 0.03), for the subgroup of content-specific items (p = 0.02), and for the global rating of communication competence (p = 0.04). The improvement observed for the subgroup of general communication skill items did not achieve significance (p = 0. 20). (2) The feeling of confidence improved in nine out of ten domains. Conclusion: While the individually-tailored CST program significantly improved the physicians' discussions of RCTs, specifically related to discussion content, what remains unknown is the influence of such programs in practice on participant recruitment rates. The study was registered retrospectively in 2010/07/22 under DRKS-ID: DRKS00000492.
doi:10.1186/s12885-017-3238-0 pmid:28403837 pmcid:PMC5390387 fatcat:r5pf2m2zzzgtfa25w5t4fht3ae

Towards leading isospin breaking effects in mesonic masses with O(a) improved Wilson fermions

Andreas Risch, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
We present an exploratory study of leading isospin breaking effects in mesonic masses using O(a) improved Wilson fermions. Isospin symmetry is explicitly broken by distinct masses and electric charges of the up and down quarks. In order to be able to make use of existing isosymmetric QCD gauge ensembles we apply reweighting techniques. The path integral describing QCD+QED is expanded perturbatively in powers of the light quarks' mass deviations and the electromagnetic coupling. We employ QED_L as a finite volume formulation of QED.
doi:10.1051/epjconf/201817514019 fatcat:cxvgk2aobvcmfpx755iteo5b7u

Light-by-light forward scattering amplitudes in Lattice QCD

Antoine Gérardin, Jeremy Green, Oleksii Gryniuk, Georg von Hippel, Harvey B. Meyer, Vladimir Pascalutsa, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
We present our preliminary results on the calculation of hadronic light-by-light forward scattering amplitudes using vector four-point correlation functions computed on the lattice. Using a dispersive approach, forward scattering amplitudes can be described by γ^* γ^* → hadrons fusion cross sections and then compared with phenomenology. We show that only a few states are needed to reproduce our data. In particular, the sum rules considered in this study imply relations between meson-γγ
more » ... and provide valuable information about individual form factors which are often used to estimate the meson-pole contributions to the hadronic light-by-light contribution to the (g-2) of the muon.
doi:10.1051/epjconf/201817506030 fatcat:5jxcs7njgfaozf5jmijo46vy6y

Nucleon average quark momentum fraction with Nf = 2+1 Wilson fermions

Konstantin Ottnad, Tim Harris, Harvey Meyer, Georg von Hippel, Jonas Wilhelm, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
We report on an analysis of the average quark momentum fraction of the nucleon and related quantities using N_f=2+1 Wilson fermions. Computations are performed on four CLS ensembles covering three values of the lattice spacing at pion masses down to M_π≈ 200 MeV. Several source-sink separations (∼ 1.0 fm to ∼ 1.4 fm) are used to assess the excited-state contamination. To gain further insight, the generalized pencil-of-functions approach has been implemented to reduce the excited-state
more » ... ion in the relevant two- and three-point functions. Preliminary results are shown for the isovector nucleon charges from vector, axial vector and tensor derivative (twist-2) operators.
doi:10.1051/epjconf/201817506026 fatcat:l4ngjw6htrerno3acvoer2l2k4

Electromagnetic form factors and axial charge of the nucleon from Nf = 2 + 1 Wilson fermions

Dalibor Djukanovic, Tim Harris, Georg M. von Hippel, Parikshit M. Junnarkar, Harvey B. Meyer, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
We present an update on our determination of the electromagnetic form factors and axial charge of the nucleon from the N f = 2 + 1 CLS ensembles with increased statistics and an additional finer lattice spacing. We also investigate the impact of O(a)improvement of the currents. Speaker,
doi:10.1051/epjconf/201817506013 fatcat:xhpixcbkm5bzzebvldinz7f6ie

Fourier transform infrared spectroscopy as a probe for the study of the hydration of lipid self-assemblies. I. Methodology and general phenomena

Walter Pohle, Carsten Selle, Hartmut Fritzsche, Hans Binder
1998 Biospectroscopy (New York, N.Y. Print)  
An algorithm for the study of the gradual hydration of phospholipid assemblies by means of Fourier transform infrared (FTIR) spectroscopy is presented. A complete series of diacyl phosphatidylcholines (PCs) including all possible analogues with palmitoyl and oleoyl residues, namely DPPC, DOPC, POPC, and OPPC, was investigated at room temperature. The lipid samples were prepared as cast films probably consisting of aligned multilamellar bilayers. The range of water activities studied in these
more » ... ms was regulated by adsorption via the gas phase corresponding to relative humidities of between 0 and 100%. Analyses of the IR-spectroscopic data have concentrated mainly on determining the amounts of water incorporated by each lipid as well as the hydrationinduced response observed for some absorption bands of the different lipids. The water uptake at high relative humidity (RH) increases with the portion of unsaturated acyl chains in the molecular structure of the PCs. Isothermal phase transitions triggered lyotropically have been detected in demonstrating the occurrence of the main transition in POPC and OPPC films at room temperature. Moreover, it appears that both lamellar phases, the gel as well as the liquid-crystalline phase, are not uniform. They seem to comprise an amazingly large span of order/disorder states of the lipid chains generally depending on the degree of hydration. As exemplified by the significant variation in the onset of wavenumber shifts for the PO 0 2 and C|O stretching-vibration modes, obtained as a function of hydration, a sequence of attachment to polar lipid binding sites by water molecules was established for DPPC. Many biomolecules are polymers containing schaft; contract grant numbers: SFB 197 and SFB 294. both hydrophilic and hydrophobic sections. In
doi:10.1002/(sici)1520-6343(1998)4:4<267::aid-bspy5>;2-# pmid:9706385 fatcat:3unfhk5t5bhhvevl5z7luewle4

Identification of a hydrogen bond in the Phe M197→Tyr mutant reaction center of the photosynthetic purple bacteriumRhodobacter sphaeroidesby X-ray crystallography and FTIR spectroscopy1

Andreas Kuglstatter, Petra Hellwig, Günter Fritzsch, Josef Wachtveitl, Dieter Oesterhelt, Werner Mäntele, Hartmut Michel
1999 FEBS Letters  
In bacterial reaction centers the charge separation process across the photosynthetic membrane is predominantly driven by the excited state of the bacteriochlorophyll dimer (D). An X-ray structure analysis of the Phe M197C CTyr mutant reaction center from Rhodobacter sphaeroides at 2.7 A î resolution suggests the formation of a hydrogen bond as postulated by Wachtveitl et al. [Biochemistry 32, 12875^12886, 1993] between the Tyr M197 hydroxy group and one of the 2a-acetyl carbonyls of D. In
more » ... nation with electrochemically induced FTIR difference spectra showing a split band of the Z Z-conjugated 9keto carbonyl of D, there is clear evidence for the existence of such a hydrogen bond.
doi:10.1016/s0014-5793(99)01614-2 pmid:10601661 fatcat:i4litn57onetzca5yi3p6utcpi

Corrigendum to: Identification of a hydrogen bond in the Phe-M197→Tyr mutant reaction center of the photosynthetic purple bacteriumRhodobacter sphaeroidesby X-ray crystallography and FTIR spectroscopy (FEBS 23044)

Andreas Kuglstatter, Petra Hellwig, Günter Fritzsch, Josef Wachtveitl, Dieter Oesterhelt, Werner Mäntele, Hartmut Michel
2000 FEBS Letters  
E-mail: fritzsch@mpibp-frankfurt.mpg. M197FY mutant RC are in line with the ones proposed in[18].  ... 
doi:10.1016/s0014-5793(00)01694-x pmid:10908737 fatcat:dhoobwhxo5enfhokktbuf5dlv4
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