| 1. |
- Bergquist, Jonas, et al.
(författare)
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New Approaches to Neurochemistry
- 2009
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Ingår i: Mass Spectrometry. - : John Wiley & Sons, Inc.. - 9780471713951 ; , s. 321-335
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Brinkmalm-Westman, Ann, 1966, et al.
(författare)
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Separation Methods
- 2009
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Ingår i: Mass Spectrometry: Instrumentation, Interpretation, and Applications. Eds. Rolf Ekman, Jerzy Silberring, Ann Westman-Brinkmalm, Agnieszka Kraj. - New York : Wiley. - 9780471713951 ; , s. 105-115
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter contains sections titled: * Chromatography * Electric-Field Driven Separations * References
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| 3. |
- Kraj, Agnieszka, et al.
(författare)
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Fingerprinting of 3, 4-methylenedioxy-methamphetamine markers by desorption/ionization on porous silicon
- 2006
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Ingår i: European journal of mass spectrometry. - : SAGE Publications. - 1469-0667 .- 1751-6838. ; 12:4, s. 253-259
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Tidskriftsartikel (refereegranskat)abstract
- Desorption/ionization on porous silicon (DIOS) is a method which extends the application range of matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry. This technique eliminates matrix background in the low mass range; DIOS is especially advantageous in research on small organic molecules and their metabolites in biological samples. DIOS mass spectrometry was applied for 3, 4-methylenedioxymethamphetamine, (MDMA, Ecstasy) impurities identification. Trace component profiling enables the identification of by-product characteristics for the synthesis route of MDMA. Ecstasy, a synthetic psychoactive drug, is highly popular among young people, and often used as a recreational drug, most commonly during disco parties. MDMA enhances feeling of euphoria by increasing the level of neurotransmitters such as serotonin, dopamine and norepinephrine and causes acute behavioral and psychological effects. MDMA is almost exclusively produced illegally, primarily in Western Europe. The new method for MDMA impurities profiling has been developed to trace the origin of MDMA pills. For comparison and classification of the impurity profiles, principal components analysis was used.
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| 4. |
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| 5. |
- Nylander, Ingrid, et al.
(författare)
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Opioid peptides in drug dependence and neurological diseases
- 1998
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Ingår i: Neurochemical markers of degenerative nervous diseases and drug addiction. - : VSP, Utrecht, The Netherlands. - 9067642770 - 978 90 67 64277 4 ; , s. 171-192
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Paulson, Linda, 1971, et al.
(författare)
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Proteomics and peptidomics in neuroscience. Experience of capabilities and limitations in a neurochemical laboratory.
- 2005
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Ingår i: Journal of mass spectrometry : JMS. - : Wiley. - 1076-5174 .- 1096-9888. ; 40:2, s. 202-13
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Forskningsöversikt (refereegranskat)abstract
- The increasing use of proteomics has created a basis for new strategies to develop methodologies for rapid identification of protein patterns in living organisms. It has also become evident that proteomics has other potential applications than protein and peptide identification, e.g. protein characterization, with the aim of revealing their structure, function(s) and interactions of proteins. In comparative proteomics studies, the protein expression of a certain biological system is compared with another system or the same system under perturbed conditions. Global identification of proteins in neuroscience is extremely complex, owing to the limited availability of biological material and very low concentrations of the molecules. Moreover, in addition to proteins, there are number of peptides that must also be considered in global studies on the central nervous system. In this overview, we focus on and discuss problems related to the different sources of biological material and sample handling, which are part of all preparatory and analytical steps. Straightforward protocols are desirable to avoid excessive purification steps, since loss of material at each step is inevitable. We would like to merge the two worlds of proteomics/peptidomics and neuroscience, and finally we consider different practical and technical aspects, illustrated with examples from our laboratory.
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| 7. |
- Sandin, Johan, et al.
(författare)
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Differential metabolism of dynorphins in substantia nigra, striatum and hippocampus
- 1997
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 18:7, s. 949-956
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Tidskriftsartikel (refereegranskat)abstract
- To map the proteolytic enzymes metabolizing dynorphins in brain structures, size-exclusion chromatography linked to electrospray ionization mass spectrometry was used. Enzymes extracted from rat hippocampus, striatum, and substantia nigra were tested for their capability of converting dynorphin-related peptides. Dynorphin A was the most resistant to proteolytic conversion, whereas Big dynorphin and dynorphin B-29 were slowly converted to dynorphin A and dynorphins A and B, respectively. Dynorphin B and alpha-neoendorphin were the least resistant. Dynorphin B was rapidly converted to Leu-enkephalin in the striatum and hippocampus but to Leu-enkephalin-Arg6 in the substantia nigra. alpha-Neoendorphin was converted to Leu-enkephalin in all tissues investigated.
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| 8. |
- Sandin, Johan, et al.
(författare)
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Metabolism of beta-endorphin in plasma studied by liquid chromatography-electrospray ionization mass spectrometry
- 1998
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 73:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- Degradation of synthetic human beta-endorphin by a human plasma proteinase was studied with high-performance liquid chromatography in combination with mass spectrometry. The peptide was metabolized at a rate of 25 pmol/min to the major fragments beta-endorphin (1-19) and (20-31), the latter reported as a potent inhibitor of morphine- and beta-endorphin-induced analgesia in mice. The proteinase responsible for this process was classified as a metal-dependent serine proteinase and was effectively inactivated by phenylmethylsulfonyl fluoride and ethylenediaminetetraacetic acid. Identification of the products formed during the enzymatic reaction was performed by liquid chromatography on-line with electrospray mass spectrometry, using a reversed-phase or a novel size-exclusion column capable of separating molecules between 0.1-7 kilodaltons. Peptide sequences were verified by tandem mass spectrometry experiments. The conversion of beta-endorphin may have physiological implications in the mechanism of pain. The obtained data suggest that several precautions should be considered during recovery and measurement of beta-endorphin in plasma by immunological techniques. The applied strategy may also be useful for studying metabolism of various peptidergic compounds with potential pharmacological significance.
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| 9. |
- Silberring, Jerzy, et al.
(författare)
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Characterization of immunoreactive dynorphin B and beta-endorphin in human plasma
- 1998
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 19:8, s. 1329-1337
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Tidskriftsartikel (refereegranskat)abstract
- Dynorphins and beta-endorphin in human plasma were characterized and studied quantitatively using radioimmunoassay, high-performance liquid chromatography (HPLC), and mass spectrometry. Most immunoreactive (ir) dynorphin B and beta-endorphin in human plasma coeluted with authentic peptides in analysis. Dynorphin A was not detected. Added to human plasma it was rapidly converted into Leu-enkephalin-Arg6 followed by elimination of the C-terminal arginine after prolonged incubation. The rate of dynorphin A conversion was estimated at 40 pmol/min/microl plasma. This process was inhibited by the thiol protease inhibitor, PHMB and by EDTA. Dynorphin B, alpha-neoendorphin and big dynorphin were virtually not metabolized by plasma proteases under the same conditions. beta-endorphin was processed into beta-endorphin(1-19) and the corresponding C-terminal counterpart beta-endorphin(20-31) at a rate of about 25 pmol/min/microl of plasma. Based on the above data, a reliable strategy was established to measure dynorphin B- and beta-endorphin-ir in human plasma samples. The basal levels in a male control group were 0.99 +/- 0.11 (n = 11) and 16.3 +/- 1.5 (n = 11) fmol/ml plasma, respectively.
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| 10. |
- Suder, Piotr, et al.
(författare)
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Identification of bikunin as an endogenous inhibitor of dynorphin convertase in human cerebrospinal fluid
- 2006
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 273:22, s. 5113-5120
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Tidskriftsartikel (refereegranskat)abstract
- Dynorphin-converting enzymes constitute a group of peptidases capable of converting dynorphins to enkephalins. Through the action of these enzymes, the dynorphin-related peptides bind to delta-opioid instead of kappa-opioid receptors, leading to a change in the biological function of the neuropeptides. In this article, we describe the identification of the protein bikunin as an endogenous, competitive inhibitor of a dynorphin-converting enzyme in human cerebrospinal fluid. This protein is present together with its target enzyme in the same body fluids. The K-M value of the convertase was found to be 9 mu M, and the K-i value of the inhibitor was 1.7 nM. The finding indicates that bikunin may play a significant role as a regulatory mechanism of neuropeptides, where one bioactive peptide is converted to a shorter sequence, which in turn, can affect the action of its longer form.
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