Search PubMed⌕ Search

Biomedical subjects

W Staudenmann

Publications and source records attributed to W Staudenmann.

22 records · Page 2Linked to original sources

Parvalbumin isoforms in chicken muscle and thymus. Amino acid sequence analysis of muscle parvalbumin by tandem mass spectrometry.

Parvalbumins are high-affinity Ca(2+)-binding proteins characterized by an EF-hand structure. Muscles of lower vertebrates contain up to five isoparvalbumins whereas higher vertebrates were believed to contain only one isoform per species. Recently Brewer et al. [Brewer, J.M., Wunderlich, J.K., & Ragland, W. (1990) Biochimie 72, 653-660] purified and sequenced a protein that they named avian thymic hormone, from chicken thymus. This protein, promoting immunological maturation of bone marrow cells in culture, was identified as a parvalbumin. The amino acid composition of this thymic parvalbumin was, however, considerably different from those of chicken muscle parvalbumin [Strehler, E.E., Eppenberger, H.M., & Heizman, C.W. (1977) FEBS Lett. 75, 127-133], suggesting the existence of two tissue-specific parvalbumins in chicken. We purified parvalbumin from chicken muscle, determined its complete amino acid sequence by tandem mass spectrometry, and showed that this protein is rather homologous to muscle parvalbumins from other species but different in 45 positions from the thymic parvalbumin. We discuss the possibility that a parvalbumin gene family might exist in higher vertebrates, expressed in a tissue-specific and developmentally regulated manner.

Amino Acid Sequence↗

Identification of new steroids in patients with 17 alpha-hydroxylase deficiency by capillary gas chromatography/mass spectrometry.

Urines of two children with 17 alpha-hydroxylase deficiency contained a number of 5-pregnane- and pregnenediols, -triols and -tetrols with a hydroxy or oxo group in position 11 of the steroid ring. They are formed mainly from progesterone via 11-hydroxyprogesterone, pregnanolone and corticosterone, respectively, or from pregnenolone. Three metabolites not previously described, 16-hydroxypregnenolone, 6,21-dihydroxypregnanediol and 6-hydroxytetrahydrocorticosterone, were identified.

Adrenal Hyperplasia, Congenital↗

High-performance liquid chromatography with column switching for the analysis of biogenic amine metabolites and pterins.

An automatic high-performance liquid chromatographic system with facilities for column switching is described which involves minimal pre-treatment of biological samples, separates complex mixtures of compounds in a short period of time and uses fluorimetric or amperometric detection. The system has been applied to the analysis of oxidized pterins in urine and reduced pterins in cerebrospinal fluid and rat brain fractions (R- and S-enantiomers of tetrahydrobiopterin resolved). The system can also be used for the analysis of most of the dopamine and serotonin metabolites in cerebrospinal fluid and brain fractions from norepinephrine to serotonin.

Animals↗

Probing protein function using a combination of gene knockout and proteome analysis by mass spectrometry.

Recently the determination of the genome sequences of three procaryotes (Haemophilus influenzae, Methanococcus jannaschii and Mycoplasma genitalium) as well as the first eucaryotic genome (Saccharomyces cerevisiae) were completed. Between 40-60% of the genes were found to code for proteins to which no function could be assigned. We describe an approach which combines proteome analysis (mapping of expressed proteins isolated by two-dimensional polyacrylamide gel electrophoresis to the genome) with genetic manipulations to study the complex pattern of protein regulation occurring in Escherichia coli in response to sulfate starvation. We have previously described the upregulation of eight spots on two-dimensional (2-D) gels in response to sulfate starvation and the assignment of six of these to entries in the E. coli genome sequence (Quadroni et al., Eur. J. Biochem. 1996, 239, 773-781). Here we describe the identification of the remaining two proteins which are encoded in a sulfate-controlled operon in the 21.5' region of the E. coli genome. Upregulated protein spots were cut from multiple 2-D gels collected and run on a modified funnel gel to concentrate the proteins and remove the sodium dodecyl sulfate before digestion. The peptide masses obtained from the digests were used to search the SwissProt database or a six-frame translation of the EMBL DNA database using a peptide mass fingerprinting algorithm. A digest can be reanalyzed after deuterium exchange to obtain a second, orthogonal data set to increase the confidence level of protein identification. The digests of the remaining unidentified proteins were used for peptide fragment generation using either post-source decay in a matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometer or collision-induced dissociation (CID) coupled mass spectrometry (MS/MS) with triple stage quadrupole or ion trap mass spectrometers. The spectra were used as peptide fragment fingerprints to search the SwissProt and EMBL databases.

Amino Acid Sequence↗