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U Schaper

Publications and source records attributed to U Schaper.

At least 19 recordsLinked to original sources

Nucleotide sequence of the P1 attachment-protein gene of Mycoplasma pneumoniae.

The specific attachment of Mycoplasma pneumoniae to the respiratory ciliated epithelium is mediated by a surface protein designated P1. The nucleotide (nt) sequence of the P1 attachment-protein gene has been determined and the amino acid (aa) sequence deduced. mRNA and cDNA sequencing confirm that this gene is transcribed in M. pneumoniae. The predicted amino acid sequence matches the N-terminal 12 aa residues of P1 protein from M. pneumoniae [Jacobs et al., J. Gen. Microbiol. 133 (1987) 2233-2236] beginning with Asn at aa position 60, where aa 1 represents the first codon of the open reading frame (ORF). Notably, the Trp at aa position 69 aligns with a UGA codon deduced from the nucleotide sequence, providing supporting evidence that UGA is read as Trp rather than stop in M. pneumoniae. Analysis of the first 59 aa suggests that it is probably a leader sequence that is processed to yield the mature protein. The codons of the mature P1 protein sequence represent 1568 aa with a calculated Mr of 169,758. A unique feature of this protein sequence is the lack of cysteine, and this was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of M. pneumoniae proteins metabolically labeled with radioactive cysteine or methionine. This study has revealed that the 4881 nt of the P1 structural gene are flanked by ORFs, and there are no obvious ribosome-binding sites or transcription termination sequences in the immediately adjacent regions. This suggests that the P1 gene is transcribed as part of a larger polycistronic message. In addition, a number of untranscribed and therefore nonfunctional P1 epitope sequences were found in the M. pneumoniae genome; their purpose remains unknown.

Adhesins, Bacterial↗

Inhibition of lipoxygenase (LOX) or of cyclooxygenase (COX) improves survival of rats in endotoxin shock.

In a well defined endotoxin (ET) shock model we compared the influence of a selective LOX-inhibitor FLM 5011 and the COX-inhibitor Acetylsalicylic acid (ASA) on survival as well as on their effects on TXB2 and 6-oxo-PGF1 and on selected parameters characterizing the shock syndrome. Pretreatment with both substances reduced the lethality rate. Neither TXB2 nor the PGF1 concentration revealed a consistent trend after therapeutic intervention. None of the investigated mediators could be identified as the primary "shock mediator".

6-Ketoprostaglandin F1 alpha↗

Influence of inhibitors of the eicosanoid metabolism, of antagonists of the eicosanoids and of PAF on mortality assayed in three biochemically characterized shock models.

Experiments were carried out to lower the mortality (LD70-90) of rats in ovalbumin-induced anaphylactic (DA) shock and in endotoxin-induced (ET) shock, and of mice after injection of Platelet-activating Factor (PAF shock) comparing the effects of the cyclooxygenase (COX)-inhibitors aspirin (ASA), indomethacin, of the COX-/lipoxygenase (LOX)-inhibitors nordihydroguajaretic acid (NDGA), phenidone and X 86 (analogue of BW 755c), of the inhibitor of thromboxane (TX) synthesis HOE 944, of the TX-antagonist BM 13177, of the PAF-antagonist BN 52021 and of ketotifen. Ketotifen was strongly effective in DA shock, COX- and LOX-inhibitors only slightly. Combined COX- and LOX-inhibitors and BN 52021 showed good effects in the ET shock. Ketotifen was inefficacious. All the used substances influenced the PAF shock. The shock syndromes were biochemically characterized by determination of isocitratedehydrogenase (ICDH) activity, lactate, glucose, haematocrit, numbers of thrombocytes and leucocytes, TXB2 and 6-keto-Prostaglandin(PG)F1 alpha.

Anaphylaxis↗

A Mycoplasma genitalium protein resembling the Mycoplasma pneumoniae attachment protein.

In previous studies with hyperimmune rabbit sera and monoclonal antibodies against the P1 protein of Mycoplasma pneumoniae, we obtained evidence of a shared antigenic determinant with a single protein of Mycoplasma genitalium. Because of biologic and morphologic similarities between these two human Mycoplasma species, attempts were made to characterize this cross-reacting protein of M. genitalium (designated MgPa). The protein was surface exposed and had an estimated molecular size of 140 kilodaltons. Electron microscopy with monoclonal antibodies produced against either MgPa or P1 demonstrated that MgPa is located over the surface of the terminal structure of M. genitalium which is covered by a nap layer. These immunologic and morphologic findings suggest that the MgPa protein of M. genitalium could be the counterpart of the P1 protein of M. pneumoniae.

Antibodies, Monoclonal↗

[Not Available].

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Blood Transfusion↗

Preliminary indication of unusual codon usage in the DNA coding sequence of the attachment protein of Mycoplasma pneumoniae.

From a Mycoplasma pneumoniae genomic library, three recombinant clones encoding approximately one-third of the attachment (P1) gene were identified. P1 fusion proteins expressed by these clones in Escherichia coli were found to be much smaller than expected from the sizes of the cloned DNA fragments. Nucleotide sequence analysis revealed the presence of UGA codons in the open reading frames of two of the clones, explaining the incomplete translation of the inserts. Sequencing data further revealed that two of the recombinant clones did have similar but not identical carboxyl-end sequences. This finding suggests the existence of more than one genomic DNA sequence coding for the 3'-end of the P1 gene. Potential transcriptional regulatory sequences, a possible termination signal at the 3'-end of the P1 gene and possible promoter-like structures, have been recognized.

Amino Acid Sequence↗