Hans Dietrich Lüdemann

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For the interpretation of chemical shift changes induced by pressure in proteins, a comparison with random-coil data is important. For providing such a data basis, the pressure dependence of the 1H-NMR chemical shifts of the amino acids X in the random-coil model peptides Gly-Gly-X-Ala were studied for the 20 common amino acids at two pH values (pH 5.0 and(More)
Temperature and hydrostatic pressure are essential in determining the assemblage of species in their specific biotopes. To evaluate the effect of high pressure on the range of viability of thermophiles, the pressure and temperature dependence of the growth of the methanogenic archaebacterium Methanococcus thermolithotrophicus was investigated. High pressure(More)
Self-diffusion coefficients for both components are reported for the highly concentrated aqueous solutions of some disaccharides and fructose as a function of temperature and concentration. These data are complemented by viscosity measurements. The disaccharides studied are sucrose, alpha,alpha-trehalose, allosucrose, and leucrose. Up to a sugar(More)
Proton magnetic resonance studies of 2'-deoxyadenosine (2'-dA), 3'-deoxyadenosine (3'-dA), 5'-deoxyadenosine (5'-dA) and 8-bromo-5'-deoxyadenosine (8-Br-5'-dA) have been carried out in the temperature range between -60 degrees and +40 degrees C for ND3 solutios, +40 degrees and +100 degrees C for D2O solutions, and finally +10 degrees and +60 degrees C for(More)
From the pressure dependence of 1H high resolution NMR spectra of two dipeptides (glycylsarcosine and N-acetyl-L-proline-NH-methylamide in the range 0.1 MPa less than p less than 150 MPa the activation volumes delta V not equal to for the amide rotation are derived, This conformational transition is characterized for glycylsarcosine by delta V not equal to(More)
Lactate dehydrogenase from rabbit skeletal muscle in the presence of substrate exhibits irreversible deactivation at hydrostatic pressures beyond 1 kbar [Schmid, G., Lüdemann, H.-D. & Jaenicke, R. (1975) Biophys. Chem. 3, 90-98]. In the absence of substrate and coenzyme the lability towards pressure is enhanced. The pH dependence of the effect and its(More)
High-pressure, high-temperature investigations on thermophilic microorganisms that grow on hydrogen or other gaseous substrates require instrumentation which provides sufficient substrate for cell proliferation up to 2 x 10 to 3 x 10 cells per ml under isothermal and isobaric conditions. To minimize H(2) leakage and to optimize reproducibility at high(More)
15N and 13C CPMAS spectra of composted plants are presented. The plants (L. rigidium and Zea mays) were grown in 15N enriched medium and fermented for several months until an approx. 80% of the dry matter was lost. In all 15N spectra the secondary amide/peptide peaks at 87 ppm contributes more than 80% of the total intensity. No new 15N peaks are formed(More)
Carbon-13 and deuteron spin lattice relaxation times T1 of concentrated solutions of trehalose and sucrose in heavy water are given as function of temperature. From the temperature dependence of the T1 ideal glass transitions temperatures T0 are derived. For both compounds the T0 derived for the disaccharides are at high concentrations larger than the T0 of(More)