[Nursing education at St. Mary's Hospital in Mühlheim on the Ruhr. Acting instead of waiting is the motto of the reorganization].
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Curriculum↗
Biomedical subjects
J Ohms
Publications and source records attributed to J Ohms.
Thermodynamic parameters of cooperative helix-to-coil transitions from synthetic A-U-rich oligoribonucleotides up to fourteen basepairs.
Heat induced helix-to-coil transitions are studied in the form of ultraviolet-hypochromicity profiles by absorbance spectroscopy, and delta Cp-curves by differential scanning calorimetry of self-complementary ribonucleotides. The results are analyzed and compared. Van 't Hoff transition enthalpies derived by UV-experiments incorporating concentration variations are found to differ from six-parameter and two-parameter Marquardt-fits on the melting profiles. A measure for the maximum number of nucleotides in intermediate states is obtained from a statistical deconvolution. It yields a range from 12.5% for the shortest nucleotide up to 31.5% for r(UA)7. Model independent calorimetric data are reported. A limit for intra-molecular loop-formation preference is reached by rG(UA)6C within this sequence.
Adenine↗
Thermodynamics of double- and triple-helical aggregates formed by self-complementary oligoribonucleotides of the type rAxUy.
The thermal denaturation of a series of oligoribonucleotides of the form rAxUy (x = 5 or 7 and y = 3-11) has been characterized by means of IR spectroscopy, UV spectroscopy, and DSC. IR spectra proved the occurrence of double- and triple-helical regions at various contents of uracil residues in the nucleotide. From DSC measurements transition enthalpies, entropies, and free enthalpies were derived. The effect of fraying in terminal base pairs of symmetrical nucleotides (x = y) was quantified. Thermodynamic excess parameters due to dangling ends (5'A and 3'U), terminal AU base pairs, and UAU base triplets were obtained by comparing DSC results from different nucleotides. Empirical values for contributions of base stacking and pairing to the stability of terminal AU base pairs have been estimated: for nucleotides under study with a high degree of fraying at the ends of the helix the major stabilization effect comes from base stacking. The size of the cooperative unit lambda in most nucleotides under study is larger than 1; i.e., in these cases intermolecular cooperation takes place. Through deconvolution of DSC data maximum populations of intermediate states FI,max were obtained. On the basis of these results all nucleotides under study were proved to melt in multistate manner. FI,max increases with the number of base pairs, decreases through dangling ends, and shows approximately constant values for triple-helical aggregates of the series rA5Uy as well as rA7Uy.
Codon↗
A thermodynamic study on rA7U7.
Ultraviolet absorbance spectroscopy and differential scanning calorimetry were employed to study the heat-induced helix-to-coil transition of the oligoribonucleotide rA7U7. The analysis of concentration-dependent ultraviolet 'melting' profiles was used to derive the van't Hoff transition enthalpy delta HUVvH (-458 kJ/mol cooperative unit). From the DSC data we calculated the calorimetric transition enthalpy delta Hcal (-412.6 kJ/mol duplex) as well as delta HcalvH (-447.9 kJ/mol cooperative unit). For the size of the cooperative unit we obtained lambda approximately 1. In contrast to this result, by means of statistical numerical deconvolution we show that intermediate states are significantly populated; at the maximum the fraction of these states reaches 25.4% of the total population. Therefore, this DSC-deconvolution technique offers a more appropriate way to register amounts of populated intermediate states which are not sufficient to obtain a value of lambda which is essentially lower than unity.
Calorimetry, Differential Scanning↗
Implications of heavy chain disease protein sequences for multiple gene theories of immunoglobulin synthesis.
The sequence of the amino-terminal 34 amino acids of gamma-heavy chain disease (gamma-HCD) protein Hi is homologous with the amino-terminal region of immunoglobulin heavy chains. gamma-heavy chain disease is smaller than a normal gamma-chain, but has the carboxy-terminal composition expected for gamma-chains and must, therefore, contain an internal deletion. Comparison of the Hi sequence with that of gamma-heavy chain disease Zu, which also has an internal deletion, indicates that the site of internal deletion is not a constant characteristic of gamma-heavy chain disease proteins. Heavy chains can be assigned to subgroups on the basis of variable region sequences. The variable regions of Hi and one other protein differ significantly from those determined for other heavy chains, and these two proteins are assigned to a new heavy chain variable region subgroup, V(HIV). It has been suggested that single immunoglobulin heavy chains are the products of two separate structural genes and that variable region genetic information is translocated and integrated into common region information. These multiple gene theories make no prediction as to whether DNA or RNA is translocated. gamma-heavy chain disease proteins provide unique information that indicates that if translocation is required for the production of immunoglobulin heavy chains, it is DNA, not RNA, that is translocated.
Amino Acid Sequence↗
A variable region subclass of heavy chains common to immunoglobulins G, A, and M and characterized by an unblocked amino-terminal residue.
Heavy chains of IgG, IgA, and IgM classes of human immunoglobulins were compared by N-terminal residue determination and partial amino acid sequence analysis. A third subclass of the variable region of heavy chains was observed; an unblocked glutamic acid as the N-terminal residue is characteristic of this subclass. Our results indicated that the heavy chain variable region subclasses are not class specific, and that a given heavy chain variable region may be found in association with constant regions for mu-chains, alpha-chains, or gamma-chains of various subclasses.
Amino Acid Sequence↗