Spontaneous intracerebral hemorrhage.
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Anti-Inflammatory Agents, Non-Steroidal↗
Biomedical subjects
R J Waugh
Publications and source records attributed to R J Waugh.
Dietary fiber and weight gain.
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Diet, Fat-Restricted↗
Structural characterization of the covalent attachment of leukotriene A3 to leukotriene A4 hydrolase.
Leukotriene A4 (LTA4) hydrolase catalyzes the conversion of the unstable epoxide LTA4 [5(S)-trans-5,6-oxido-11,14-cis-eicosatetraenoic acid] into proinflammatory LTB4. During the process of catalyzing this reaction, the enzyme is suicide inactivated by its substrate. In addition, LTA3, and analogue of LTA4 that lacks the C14-C15 double bond, is a potent suicide inhibitor of LTA4 hydrolase. We have synthesized [3H]LTA3 and used this ligand to demonstrate that LTA3 can covalently label LTA4 hydrolase and that this labeling is specifically competed for by bestatin and LTA4. Incubation of recombinant human LTA4 hydrolase with LTA3 followed by proteolysis (endoproteinase Lys-C) resulted in a peptide map with a single modified peptide defining the location of the LTA3 covalent attachment region. This modified 21-amino-acid peptide had a UV absorption spectrum corresponding to a conjugated triene chromophore which established conservation of this structural unit after covalent interaction of LTA3 with LTA4 hydrolase. MALDI-TOF mass spectrometric analysis of the 21-amino-acid peptide adduct revealed an abundant MH+ at m/z 2658, consistent with the predicted nominal mass of the sequenced peptide with the addition of a single LTA3 moiety. Proteolysis of LTA4 hydrolase modified with LTA3 was performed sequentially with endo-Asp-N and endo-Lys-C. The resulting peptide isolated by reverse-phase high-performance liquid chromatography was analyzed by mass spectroscopy revealing two related peptides, D371-K385 (m/z 2018.0) and D375-K385 (m/z 1577.8), both of which retained the elements of LTA3. Postsource decay of m/z 1577.8 resulted in an abundant ion at m/z 536 and an ion of lesser abundance at m/z 856 consistent with cleavage between V381 and P382 that supported assignment of the modified tyrosine residue at Y383. These results suggest nucleophilic attack of a tyrosine residue (Y383) at the conjugated triene epoxide of LTA3 resulting in a triene ether carbinol covalent adduct.
Amino Acid Sequence↗
The maculatin peptides from the skin glands of the tree frog Litoria genimaculata: a comparison of the structures and antibacterial activities of maculatin 1.1 and caerin 1.1.
Six peptides have been isolated and characterized from the dorsal glands of the tree frog Litoria genimaculata. One of these is the known hypotensive peptide caerulein; the others have been named maculatins. The amino acid sequences of the maculatin peptides have been determined using a combination of fast atom bombardment mass spectrometry and automated Edman sequencing. Four of the maculatin peptides show antibiotic activity, with maculatin 1.1 [GLFGVLAKVAAHVVPAIAEHF(NH2)] showing the most pronounced activity, particularly against gram-positive organisms. Maculatin 1.1 resembles the known caerin 1 antibiotic peptides, except that four of the central amino acid residues (of the caerin 1 system) are missing in maculatin 1.1. A comparison of the antibiotic activity of maculatin 1.1 with those of caerin 1.1 is reported.
Amino Acid Sequence↗
New caerin antibacterial peptides from the skin glands of the Australian tree frog Litoria xanthomera. Part 2. Sequence determination using mass spectrometry and associated techniques.
Mass spectrometric sequencing, enzymic digestion and Edman degradation provide the structures of the two antimicrobial peptides from the skin glands of the Australian tree frog Litoria xanthomera as:- Gly Leu Phe Ser Val Leu Gly Ala Val Ala Lys His Val Leu Pro His Val Val Pro Val Ile Ala Glu Lys Leu (NH2) (caerin 1.6), and Gly Leu Phe Lys Val Leu Gly Ser Val Ala Lys His Leu Leu Pro His Val Ala Pro Val Ile Ala Glu Lys Leu (NH2) (caerin 1.7).
Amino Acid Sequence↗
Identification and relative quantitation of F2-isoprostane regioisomers formed in vivo in the rat.
F2-isoprostanes are a complex mixture of isomers formed in four regioisomeric family types by free radical-initiated oxidation of arachidonic acid present in membrane phospholipids. F2-isoprostanes isolated from the livers of rats treated with carbon tetrachloride were separated by initial reverse phase HPLC and detected using electrospray ionization mass spectrometry with the characteristic loss of 44 u (C2H4O) from the common 1,3-diol cyclopropane ring found in these eicosanoids. Collision induced decomposition of the carboxylate anions from the separated F2-isoprostanes formed abundant ions characteristic for regioisomers of Type I (m/z 115), Type III (m/z 127), and Type IV (m/z 193), which made possible characterization of these three family subtypes by LC/MS/MS. Capillary GC/MS was employed to further identify the F2-isoprostane regioisomers using electron ionization mass spectrometry and to obtain characteristic mass spectra of the pentafluorobenzyl ester trimethylsilyl ether derivatives. Quantitation of the F2-isoprostanes separated by both reverse-phase HPLC and capillary GC/MS was carried out using negative ion chemical ionization mass spectrometry. The most abundant isomers identified were Type I and IV regioisomers constituting 33 and 25% of the total products, respectively. As expected, the Type II and III regioisomer products were of less abundance. Over 45 F2-isoprostanes could be separated in this complex mixture, suggesting random production of each regioisomeric subtype in this in vivo model.
Animals↗
Characterization of underivatized tetrapeptides by negative-ion fast-atom bombardment mass spectrometry.
The [M-H]- ions derived from tetrapeptides generally show two different collision-induced backbone cleavages which allow the determination of the amino acid sequence of the peptide. The first of these involves the formation of the carboxylate anions of either constituent amino acids or fragment peptides. In the second, amino acids or fragment peptides are eliminated as neutrals. There are a number of residues which undergo characteristic side-chain fragmentations irrespective of their position in the tetrapeptide, e.g. Ser, Thr, Cys, Met, Phe, and Tyr. However, there are also some residues which, when situated at the C-terminal end of the peptide, promote pronounced fragmentation at the C-terminal position which occurs to the exclusion of the normal backbone cleavages. We conclude that the data obtained from these negative-ion cleavages are analytically useful, and complement those provided by the cognate positive-ion technique.
Amino Acid Sequence↗
A simple method for differentiating Leu and Ile in peptides. The negative-ion mass spectra of [M-H]- ions of phenylthiohydantoin Leu and Ile.
Phenylthiohydantoin (PTH) amino acid derivatives are formed during sequential Edman degradation of peptides and proteins. Isomeric Leu and Ile (which differ only in respectively having iso-butyl and sec-butyl chains, and are often difficult to distinguish by conventional mass spectrometric techniques) may be readily identified by the characteristic decompositions of the [M-H]- ions of their PTH derivatives. The Leu spectrum shows major loss of propane, while that of the Ile derivative shows elimination of both methane and ethane. This method may be used routinely with 10 microgram quantities of peptide material.
Isoleucine↗
Plain word for "passed flatus".
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Athletic Injuries↗
Administrative receivership and troika management.
The authors describe the use of troika management and administrative receivership to upgrade a unit in a state mental hospital. The experiment included a three person unit chief, transitional leadership, and collective decision making.
Administrative Personnel↗
New caerin antibacterial peptides from the skin glands of the Australian tree frog Litoria xanthomera.
The secretion of the skin glands of the 'orange-thighed frog' Litoria xanthomera contains seven peptides. One of these is the know hypotensive peptide caerulein. Two new peptides, caerin 1.6 [GLFSVLGAVAKHVLPHVVPVIAEKL(NH2)], and caerin 1.7 [GLFKVLGSVAKHLLPHVAPVIAEKL(NH2)] show antibacterial properties. Two other peptides lack the first two amino acid residues of caerins 1.6 and 1.7 and show no antibacterial activity. The identification of the peptides in Litoria xanthomera confirms that this species is related to Litoria caerula, Litoria gilleni and Litoria splendida but not as closely as those three species are related to each other.
Amino Acid Sequence↗
The structures of the frenatin peptides from the skin secretion of the giant tree frog Litoria infrafrenata.
The granular dorsal glands of the giant tree frog Litoria infrafrenata contain five peptides including caerulein (a known neuropeptide), and four new peptides named franatins 1 (MH+ = 1140 Da), 2 (1423), 3 (2180), 4 (2493). The amino acid sequences of the frenatins are detailed: their structures do not correspond to those of peptides isolated from other amphibians or animals. Frenatin 3, Gly-Leu-Met-Ser-Val-Leu -Gly-His-Ala-Val-Gly-Asn-Val-Leu-Gly-Gly-Leu-Phe-Lys-Ser-(OH), has wide spectrum antimicrobial properties.
Amino Acid Sequence↗