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Biomedical subjects

W Machleidt

Publications and source records attributed to W Machleidt.

At least 91 records · Page 5Linked to original sources
PubMed1983

Protein inhibitors of cysteine proteinases. III. Amino-acid sequence of cystatin from chicken egg white.

Cystatin, the protein inhibitor of cysteine proteinases from chicken egg white was purified by a new method. The two major forms with pI 6.5 (Peak I) and 5.6 (Peak II) were separated. Molecular masses of both forms are approx. 12700 Da as determined by gel chromatography; Form A from Peak I has a molecular mass of 12191 Da as calculated from its amino-acid sequence. The complete amino-acid sequence of Form A was determined by automated solid-phase Edman degradation of the whole inhibitor and its cyanogen bromide fragments. It contains 108 amino-acid residues. Form B from Peak II represents an elongation of Form A by 8 amino-acid residues at the N-terminus. Cystatin contains four cysteine residues, presumably forming two disulphide bridges. Comparison of the amino-acid sequences and near ultraviolet circular dichroism spectra of stefin, the cysteine proteinase inhibitor from human granulocytes, and cystatin shows that the two proteins are entirely different. According to the primary structures, probably neither proteinase inhibitor is involved in a thiol-disulphide exchange mechanism in the interaction with its target enzyme.

Amino Acid Sequence↗
PubMed1983

Amino-acid sequence of the smallest protein of the cytochrome c1 subcomplex from beef heart mitochondria.

A cytochrome c1 subcomplex was obtained from purified complex III. The subcomplex consists of three protein subunits, present at an equimolar stoichiometry. The primary structures of two of these proteins, the heme-carrying cytochrome c1 and a protein with a molecular mass of 9175 Da, have been published by Wakabayashi et al. The covalent structure of the smallest subunit is presented in this paper. This protein consists of 62 amino acid residues; its molecular mass was calculated to be 7189 Da. The sequence was determined by complete solid-phase Edman degradation of the uncleaved polypeptide and was confirmed by sequencing the C-terminal fragment resulting from cleavage of a single tryptophyl bond.

Amino Acid Sequence↗
PubMed1983

[Circadian, infradian and seasonal changes in neural conduction velocity with reference to effects of temperature; I.: Circadian rhythm].

Using results of two collectives (one cross-section study covering 212 individuals and a longitudinal study of 10 individuals over a period of 4 days with 4 examinations/individual/day) circadian, infradian and seasonal influences on the changes observed are considered. The skin temperatures displayed significant circadian variations subsequent to electrical stimulation in 4 of 5 topographic regions from which the measurements were performed. Before stimulation in only one of five regions significant circadian changes were observed. Thus stimulation caused an increase in amplitude but no changes in phase. Pre- and post-stimulation rhythms were in phase. There was found a two-peaked circadian rhythm with maxima at late noon and at midnight. Probably there were systematic differences in skin temperature in the upper extremities compared to the lower ones. The latter showed a minimum in the early morning hours. The circadian effects are presented almost completely free of temperature influences for the sensory NCV of the n. medianus on the hand. As opposed to the simultaneously acquired 2-peaked circadian rhythm of the skin temperature an almost continuous decrease in the NCV can be observed from the early morning until midnight. After midnight there was an abrupt increase of the NCV by about 5%. The significant influences of the time-of-day on the NCV of the upper- and lower-arm could not be attained independent of temperature influences. It was nonetheless apparent that the motor and sensory NCV of the lower arm increased throughout the day in contrast to the NCV of the hand. Possibly, local' influences interfered thereby with the autonomic rhythm of the nerve.

Adolescent↗
PubMed1983

[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↗
PubMed1982

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↗
PubMed1980

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↗
PubMed1978

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↗
PubMed1978

[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↗