Revised primary structures of rat pituitary gamma-lipotrophin and beta-endorphin.

In-depth investigations, by high performance liquid chromatographic purification, radio-immunoassay, mass spectrometry, tandem mass spectrometry, Edman sequencing and limited C-terminal ladder sequencing, were prompted by mass spectrometric charting experiments which suggested that the amino acid sequences for rat gamma-lipotrophin and beta-endorphin require revision. The results for gamma-lipotrophin identify a histidine for glutamine substitution at position 12, and heterogeneity in the expressed protein presumably due to partial dehydration. Partial dehydration for acidic joining peptide, previously reported by Toney et al was corroborated.

Proferrorosamines and phytopathogenicity in Erwinia spp.

Proferrorosamine A (pFR A) of the plant pathogenic bacterium Erwinia rhapontici was shown to inhibit growth of wheat and cress seedlings at the > or = 10 ppm level. When the seeds were continuously exposed to 100 ppm pFR A, the germination of cress and wheat seeds was inhibited up to 90% and 80%, respectively. The inhibition could be reversed through addition of equimolar amounts of ferrous iron, which indicates that the strong iron chelating capability of pFR A is responsible for the observed effect.

Proferrioxamine synthesis in Erwinia amylovora in response to precursor or hydroxylysine feeding: metabolic profiling with liquid chromatography-electrospray mass spectrometry.

Metabolic profiling by capillary liquid chromatography-electrospray mass spectrometry was used to monitor shifts in the proferrioxamine profiles of Erwinia amylovora in response to externally supplied potential proferrioxamine precursors, selected stable-isotope-labeled precursors and atypical precursors. Based on the qualitative and quantitative shifts in the proferrioxamine profiles, lysine and arginine are unambiguous, and agmatine, ornithine, diaminobutyric acid and the corresponding C3-5 diamines are highly likely precursors for proferrioxamine biosynthesis in E. amylovora.

On the collision-activated fragmentation of proferrioxamines: Evidence for a succinimide-mediated mechanism.

The fragmentation mechanism of acyclic proferrioxamines has been studied by tandem mass spectrometry in a triple stage quadrupole mass analyzer by using activation in the collision cell as well as in the high pressure region prior to the first mass analyzer. The data suggest that proferrioxamines fragment preferentially at the hydroxamate bonds via cyclic rearrangement to succinimide derivatives. This pattern was observed most clearly for the peracetyl derivatives, in which the influence of terminal functional groups was masked.

Metabolism of polyamines and basic amino acids in Erwinia amylovora: application of liquid chromatography/electrospray mass spectrometry to proferrioxamine precursor feeding and inhibition studies.

Erwinia amylovora, the etiological agent of fire blight, produces a family of proferrioxamine siderophores, which may be essential for the pathogen to establish itself in its hosts. If so, then control of fire blight may perhaps be possible via interference with proferrioxamine biosynthesis. Proof of this hypothesis requires prior knowledge of the corresponding biosynthetic pathways in E.

Profiling of basic amino acids and polyamines in microbial culture supernatants by electrospray mass spectrometry.

As part of our efforts to investigate the biosynthesis of proferrioxamines in Erwinia amylovora, it was of interest to develop a methodology with which a large number of basic amino acids, di- and polyamines, and C- and N-hydroxy derivatives thereof could be monitored simultaneously. Towards this end, the on-line coupling of electrospray mass spectrometry with ion chromatography or reversed-phase chromatography was explored. Tandem mass spectrometry was found to be an excellent method for obtaining relevant structural information on underivatized polyamines and basic amino acid, including N-hydroxy derivatives.

Gas chromatography/electron impact mass spectrometry, fast atom bombardment mass spectrometry, mass-analyzed ion kinetic energy spectroscopy and B/E linked scan analysis of triaryl phosphates and triethylene glycol fatty acid esters.

Tris(isopropylphenyl/phenyl) phosphates and triethylene glycol dicaprate/caprylate mixtures of typical industrial compositions have been analyzed by fast atom bombardment (FAB) mass spectrometry, FAB collisional activation (CA) mass-analyzed ion kinetic energy spectroscopy and FAB/electron impact (EI) CA B/E linked scans. Data obtained by these state-of-the-art methodologies are compared qualitatively and semi-quantitatively with those provided by classical gas chromatography (GC)/EI MS. To identify the plasticizers in cases of suspected contamination, GC/EI MS still appears to be the method of choice whenever ultimate sensitivity and specificity are needed.

Mass spectrometric charting of bovine posterior/intermediate pituitary peptides.

The feasibility for charting neuropeptides in neuroendocrine tissues on the basis of the universal property and inherent specificity of their molecular weights was explored. As a model, a comprehensive MS analysis of extractable peptides from bovine posterior/intermediate pituitary was performed. Two suitable MS techniques--namely, plasma-desorption time-of-flight and fast atom bombardment MS--were evaluated, and each method could identify more than 20 peptides, including N-terminally acetylated and C-terminally amidated species.

6-Acetylmorphine: a natural product present in mammalian brain.

Recently, we described three substances in bovine hypothalamus, adrenal, and rat brain recognized by antisera raised against morphine, and we identified one as morphine and another as codeine by GC/MS. We now report the identification of the third immunoreactive (ir) morphinan from bovine brain as 6-acetylmorphine by chemical conversion to morphine, GC/MS, and high-resolution mass measurement. 6-Acetylmorphine has not previously been described as a natural product in plants or animals, but it has long been known as the metabolite in part responsible for the biological properties of heroin.

Plasticizers as contaminants in commercial ethanol.

A batch of 95% ethanol caused unusually strong disordering of biomembranes, which could be detected either by fluorescence anisotropy in synaptosomal membranes or by electron paramagnetic resonance spectroscopy in erythrocyte membranes. The contaminated batches of ethanol were visibly fluorescent when evaporated on filter paper. The adulterants were separated by capillary gas chromatography and the ubiquitous pollutant dioctylphthalate was identified by its low resolution electron impact mass spectrum.

Characterization of 2,3-dihydroxybenzoic acid from Nocardia asteroides GUH-2.

Culture filtrates of virulent Nocardia asteroides GUH-2 after growth in acetate minimal medium displayed an absorbance maximum at 320 nm. After isolation by polyamide extraction and anion chromatography, a UV-active compound with this absorbance was shown to be 2,3-dihydroxybenzoic acid (DHB) by nuclear magnetic resonance, gas chromatographic, and mass spectrometric techniques. DHB production under several culture conditions was quantified by a standard high-pressure liquid chromatography assay.

Pancreastatin, a novel pancreatic peptide that inhibits insulin secretion.

In mammalian tissues the C-terminal amide structure has been found to occur only in neuroactive or hormonally-active peptides. About half known neuropeptide and peptide hormones have this unique chemical feature. Using a chemical detection method, a search for previously unknown peptides that possess the C-terminal amide structure in extracts of brain and intestine was carried out and a number of novel neuropeptides and hormonal peptides, designated neuropeptide Y, PHI, peptide YY, galanin and neuropeptide K were isolated.

Morphine and codeine from mammalian brain.

Recently, we described the presence of six immunoreactive (ir) morphinans in bovine adrenal and hypothalamus and identified one as morphine [Goldstein, A., Barrett, R. W.