[The body concept for prostate carcinoma patients. Development and testing of a questionnaire which ascertains uro-oncological patients' attitudes to their own bodies under the influence of surgery-conditioned consequences]. / Das Körperkonzept von Prostatakarzinompatienten. Entwicklung und Testung eines Fragebogens für die Erfassung von Einstellungen uro-onkologischer Patienten zum eigenen Körper unter den Einfl üssen operationsinduzierter Folgen.

BACKGROUND: The aim of this study is the construction of a questionnaire which determines uro-oncological patients' attitudes to their own bodies. The questionnaire will be tested by means of psychometric criteria for suitability. In this way, the emotional-affective and perceptual--cognitive characteristics of the body concept will be detected more effectively. PARTICIPANTS AND METHODS: For the construction, 12 interviews with patients were conducted and items from four body concept questionnaires were analysed. Subsequently, a draft version, containing 133 items, was written. A total of 305 participants (PCa n=205; healthy n=100) were questioned in 2 studies. Thereafter the suitability of the items could be checked by psychometric and factor analytical criteria. RESULTS: The psychometric testing of the statements led to a selection of the items. 40 items could be established as applicable and were therefore accepted for the final questionnaire. CONCLUSION: The indentified scales show good psychometric characteristics and also differentiate between the healthy and the clinical samples. Preliminary analyses prove the validity of the scales, although this should be subjected to further testing for assurance.

The polypeptide tunnel system in the ribosome and its gating in erythromycin resistance mutants of L4 and L22.

Variations in the inner ribosomal landscape determining the topology of nascent protein transport have been studied by three-dimensional cryo-electron microscopy of erythromycin-resistant Escherichia coli 70S ribosomes. Significant differences in the mouth of the 50S subunit tunnel system visualized in the present study support a simple steric-hindrance explanation for the action of the drug. Examination of ribosomes in different functional states suggests that opening and closing of the main tunnel are dynamic features of the large subunit, possibly accompanied by changes in the L7/L12 stalk region. The existence and dynamic behavior of side tunnels suggest that ribosomal proteins L4 and L22 might be involved in the regulation of a multiple exit system facilitating cotranslational processing (or folding or directing) of nascent proteins.

An extended RNA binding surface through arrayed S1 and KH domains in transcription factor NusA.

The crystal structure of Thermotoga maritima NusA, a transcription factor involved in pausing, termination, and antitermination processes, reveals a four-domain, rod-shaped molecule. An N-terminal alpha/beta portion, a five-stranded beta-barrel (S1 domain), and two K-homology (KH) modules create a continuous spine of positive electrostatic potential, suitable for nonspecific mRNA attraction. Homology models suggest how, in addition, specific mRNA regulatory sequences can be recognized by the S1 and KH motifs. An arrangement of multiple S1 and KH domains mediated by highly conserved residues is seen, creating an extended RNA binding surface, a paradigm for other proteins with similar domain arrays. Structural and mutational analyses indicate that the motifs cooperate, modulating strength and specificity of RNA binding.

Expression, purification, crystallization and preliminary X-ray diffraction studies of bacterial and archaeal L4 ribosomal proteins.

Ribosomal protein L4 is implicated in the peptidyltransferase activity of the ribosome and in certain bacteria it regulates the transcription and translation of the 11-gene S10 operon. The genes for the L4 ribosomal proteins from the hyperthermophilic bacterium Thermotoga maritima and the halophilic archaeon Haloarcula marismortui have been PCR amplified from genomic DNA and cloned under the control of a T7 promoter to generate overexpressing Escherichia coli strains. For both proteins, efficient purification procedures were developed to yield material suitable for crystallization trials. Crystals of T. maritima L4 were obtained in the orthorhombic space group P2(1)2(1)2(1), with one molecule per asymmetric unit, diffracting to 1.7 A resolution with synchrotron radiation. Crystals of H. marismortui L4 belonged to the trigonal space group P3(1)21 or P3(2)21 and diffracted to 3.2 A resolution with a rotating-anode source, presumably containing three molecules per asymmetric unit. The results demonstrate that for certain halophilic proteins the same purification and crystallization procedures can be employed as for conventional proteins.

Crystal structure of ribosomal protein L4 shows RNA-binding sites for ribosome incorporation and feedback control of the S10 operon.

Ribosomal protein L4 resides near the peptidyl transferase center of the bacterial ribosome and may, together with rRNA and proteins L2 and L3, actively participate in the catalysis of peptide bond formation. Escherichia coli L4 is also an autogenous feedback regulator of transcription and translation of the 11 gene S10 operon. The crystal structure of L4 from Thermotoga maritima at 1.7 A resolution shows the protein with an alternating alpha/beta fold and a large disordered loop region. Two separate binding sites for RNA are discernible. The N-terminal site, responsible for binding to rRNA, consists of the disordered loop with flanking alpha-helices. The C-terminal site, a prime candidate for the interaction with the leader sequence of the S10 mRNA, involves two non-consecutive alpha-helices. The structure also suggests a C-terminal protein-binding interface, through which L4 could be interacting with protein components of the transcriptional and/or translational machineries.

Kinetics and inhibition of recombinant human cystathionine gamma-lyase. Toward the rational control of transsulfuration.

The gene encoding human cystathionine gamma-lyase was cloned from total cellular Hep G2 RNA. Fusion to a T7 promoter allowed expression in Escherichia coli, representing the first mammalian cystathionine gamma-lyase overproduced in a bacterial system. About 90% of the heterologous gene product was insoluble, and renaturation experiments from purified inclusion bodies met with limited success. About 5 mg/liter culture of human cystathionine gamma-lyase could also be extracted from the soluble lysis fraction, employing a three-step native procedure. While the enzyme showed high gamma-lyase activity toward L-cystathionine (Km = 0.5 mM, Vmax = 2.5 units/mg) with an optimum pH of 8.2, no residual cystathionine beta-lyase behavior and only marginal reactivity toward L-cystine and L-cysteine were detected. Inhibition studies were performed with the mechanism-based inactivators propargylglycine, trifluoroalanine, and aminoethoxyvinylglycine. Propargylglycine inactivated human cystathionine gamma-lyase much more strongly than trifluoroalanine, in agreement with the enzyme's preference for C-gamma-S bonds. Aminoethoxyvinylglycine showed slow and tight binding characteristics with a Ki of 10.5 microM, comparable with its effect on cystathionine beta-lyase. The results have important implications for the design of specific inhibitors for transsulfuration components.