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Biomedical subjects

W Machleidt

Publications and source records attributed to W Machleidt.

At least 109 records · Page 6Linked to original sources

[Circadian, infradian and seasonal changes in neural conduction velocity with reference to the effects of temperature. II: Infradian and seasonal changes].

Using the longitudinal study it was shown that a number of sensory neurographic parameters changed systematically throughout the 4-day investigation. In particular the sensory NCV of the n. medianus of the hand increased significantly. Possible causes i.e. the activation of the metabolism are discussed. Should this assumption prove to be true repetitive stimulation of a nerve could have a therapeutic effect. The seasonal influences are displayed using the results of a cross-sectional study. Six out of 21 neurographic parameters showed significant seasonal variations. In the NCVs of the n. medianus and the n. ulnaris maxima were present in summer and autumn while the NCVs of the lower extremities had minima. In winter and spring differences between the NCVs of the lower and upper arm and leg were lowest. These differences may be caused by seasonal changes of the metabolism which modifies the coefficient of the temperature of the neurographic parameters.

Circadian Rhythm↗

Subunit 1 of cytochrome oxidase from Neurospora crassa: nucleotide sequence of the coding gene and partial amino acid sequence of the protein.

A partial protein sequence (223 residues) of cytochrome oxidase subunit 1 from Neurospora crassa has been established. The nucleotide sequence of a cloned mitochondrial DNA segment, including the structural gene coding for the mature subunit 1 (CO I locus) was determined. In contrast to the situation in yeast, the CO I locus in N. crassa is not interrupted by long intervening sequences. A polypeptide of 555 residues with a mol. wt. of 61 000 has been deduced from the reading frame established by protein sequencing. With the exception of the C-terminal part of the polypeptide, the proposed sequences for subunit 1 of N. crassa, yeast, and man are largely homologous. Protein sequencing reveals that a region of low homology close to the C-terminal portion belongs to the structural gene in N. crassa. The DNA sequence coding for the prepiece , which characterizes the polypeptide precursor of the N. crassa subunit 1, has not yet been localized. A RNA species of approximately 6.8 kb has been identified as the CO I transcript. There is no indication of splicing of this large transcript.

Amino Acid Sequence↗

N,N'-dicyclohexylcarbodiimide binds specifically to a single glutamyl residue of the proteolipid subunit of the mitochondrial adenosinetriphosphatases from Neurospora crassa and Saccharomyces cerevisiae.

The N,N'-dicyclohexylcarbodiimide-binding proteolipid subunit of the mitochondrial adenosinetriphosphatases (ATP phosphohydrolase, EC 3.6.1.3) of Neurospora crassa and Saccharomyces cerevisiae were purified from mitochondria incubated with the radioactively labeled inhibitor. The specifically labeled subunit was cleaved with cyanogen bromide and N-bromosuccinimide, and the resultant fragments were separated by gel chromatography in the presence of 80% (vol/vol) formic acid. The N,N'-dicyclohexylcarbodiimide label was recovered in each organism exclusively in a 17-residue fragment. Further analysis by automated solid-phase Edman degradation revealed that the bound label was present at only one position, corresponding to a glutamyl residue. The N,N'-dicyclohexylcarbodiimide-modified glutamyl residue is the only identical acidic position in both proteins and occurs in the middle of a hydrophobic sequence of about 25 residues.

Adenosine Triphosphatases↗

Isolation of precursors of cytochrome oxidase from Neurospora crassa: application of subunit-specific antibodies and protein A from Staphylococcus aureus.

A novel immunological procedure has been applied for the isolation of precursors of cytochrome oxidase. It involves antibodies to individual subunits of the oxidase and protein A from Staphylococcus aureus linked to a Sepharose support. Unassembled (free) 'subunits' as well as a labile complex containing five polypeptide components of the oxidase were isolated from mitochondrial extracts by this technique. The procedure is superior to the previously used double-immuno-precipitation method, because of its quantitative nature, its sensitivity, rapidity and versatility. Thus, sequential titrations of precursor proteins by addition of various subunit-specific immuno-globulins to an individual extract become feasible. Furthermore, the technique is suitable for the isolation of precursors on a large scale. To avoid contamination of the polypeptide preparations with immunoglobulin, the antibodies were covalently coupled to protein A, which had been previously linked to Sepharose. A radioactive preparation of unassembled subunit 1 of cytochrome oxidase was isolated by such a modified support and its cyanogen-bromide-cleavage products were compared to those of subunit 1 obtained from the assembled enzyme.

Animals↗

[Annual rhythms in frequency of electroencephalographic patterns (author's transl)].

A series of electroencephalographic features were measured for about 11,500 patients from a clinical population, over a period of five years (1972 to 1976) and were documented using a standarized procedure. It could be shown that for males a definite yearly rhythm was present for the relative frequencies of alpha-type, partial beta-type, and low voltage EEGs, as well as for continuous and grouped dysrhythmias, the amplitudes of which were in the main 20--30% of the average. For females on the other hand, apart from grouped dysrhythmias, no such yearly rhythms could be proven, at the most such with a periodicity of between 14 and 16 months. The data often display trends that are more distinct than the rhythmicity and as such these should be taken into consideration when deciding upon the model used for statistical regression.

Alpha Rhythm↗

Amino-acid sequence of a coelenterate toxin: toxin II from Anemonia sulcata.

Toxin II from Anemonia sulcata, the main component of the sea anemone venom, consists of 47 amino acid residues which are interconnected by three disulfide bridges. The S-aminoethylated polypeptide was coupled to activated glass beads and sequenced to position 33 by automated solid-phase Edman degradation. Blanks arising from anchor points and the rest of the sequence were determined from tryptic peptides of the [14C]carboxymethylated toxin. Toxin II shows no significant homologies with other known sequences of neurotoxins or cardiotoxins. It might constitute a new class of polypeptide toxins.

Amino Acid Sequence↗