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Peptidome analysis of cerebrospinal fluid by LC-MALDI MS.

Hölttä M, Zetterberg H, Mirgorodskaya E, Mattsson N, Blennow K, Gobom J - PLoS ONE (2012)

Bottom Line: Analysis of the extracts by offline LC-MALDI MS resulted in the detection of 3,000-4,000 peptide-like features.Out of these, 730 peptides were identified by MS/MS.The identified peptides were found to originate from 104 proteins, of which several have been reported to be involved in different disorders of the central nervous system.

View Article: PubMed Central - PubMed

Affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.

ABSTRACT
We report on the analysis of endogenous peptides in cerebrospinal fluid (CSF) by mass spectrometry. A method was developed for preparation of peptide extracts from CSF. Analysis of the extracts by offline LC-MALDI MS resulted in the detection of 3,000-4,000 peptide-like features. Out of these, 730 peptides were identified by MS/MS. The majority of these peptides have not been previously reported in CSF. The identified peptides were found to originate from 104 proteins, of which several have been reported to be involved in different disorders of the central nervous system. These results support the notion that CSF peptidomics may be viable complement to proteomics in the search of biomarkers of CNS disorders.

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Related in: MedlinePlus

Identified endogenous peptides from (a) Amyloid beta A4 protein isoform h precursor (A4_HUMAN, commonly referred to as APP) and (b) from Amyloid-like protein 1 isoform 1 (APLP1).The peptides identified from A4_HUMAN are all located within the β-amyloid peptide, starting at or in proximity of the N-terminus of the peptide, defined by the BACE cleavage site. Correspondingly, four of the peptides identified in APLP1 are generated by BACE cleavage C-terminally to Arg-567.
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pone-0042555-g005: Identified endogenous peptides from (a) Amyloid beta A4 protein isoform h precursor (A4_HUMAN, commonly referred to as APP) and (b) from Amyloid-like protein 1 isoform 1 (APLP1).The peptides identified from A4_HUMAN are all located within the β-amyloid peptide, starting at or in proximity of the N-terminus of the peptide, defined by the BACE cleavage site. Correspondingly, four of the peptides identified in APLP1 are generated by BACE cleavage C-terminally to Arg-567.

Mentions: The amyloid beta A4 protein (amyloid precursor protein, APP) plays a central role in the pathophysiological processes in AD, which is characterized by progrediating neuronal degeneration with amyloid deposits [32]. By enzymatic processing of APP, the peptide amyloid beta (Aβ) 1–42 is generated which is highly prone to aggregation and is the major constituent of the amyloid plaques that form in the brain. Aβ1–42 is also used as a CSF biomarker for AD [33]. In this study, we detected Aβ1–14, 1–15, 1–16, 1–17, 1–19, and 5–15 (Figure 5 a). The existence of several of these fragments have been recently reported in CSF in a study using immunoprecipitation in combination with mass spectrometry [34]. The C-termini of these fragments span the α-secretase cleavage site and may thus be markers of non amyloidogenic APP processing that may be protective from AD [35]. The identification of Aβ5–15 is the first report of this truncated form in CSF. The identification of Aβ peptides starting at position 5 is especially interesting since such peptides may represent the activity of an APP processing pathway that is up-regulated after inhibition of the major Aβ producing enzyme BACE1 [36], [37] and CSF Aβ5-X peptides may be useful as pharmacodynamic markers in trials of BACE1-inhibitors [38].


Peptidome analysis of cerebrospinal fluid by LC-MALDI MS.

Hölttä M, Zetterberg H, Mirgorodskaya E, Mattsson N, Blennow K, Gobom J - PLoS ONE (2012)

Identified endogenous peptides from (a) Amyloid beta A4 protein isoform h precursor (A4_HUMAN, commonly referred to as APP) and (b) from Amyloid-like protein 1 isoform 1 (APLP1).The peptides identified from A4_HUMAN are all located within the β-amyloid peptide, starting at or in proximity of the N-terminus of the peptide, defined by the BACE cleavage site. Correspondingly, four of the peptides identified in APLP1 are generated by BACE cleavage C-terminally to Arg-567.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3412831&req=5

pone-0042555-g005: Identified endogenous peptides from (a) Amyloid beta A4 protein isoform h precursor (A4_HUMAN, commonly referred to as APP) and (b) from Amyloid-like protein 1 isoform 1 (APLP1).The peptides identified from A4_HUMAN are all located within the β-amyloid peptide, starting at or in proximity of the N-terminus of the peptide, defined by the BACE cleavage site. Correspondingly, four of the peptides identified in APLP1 are generated by BACE cleavage C-terminally to Arg-567.
Mentions: The amyloid beta A4 protein (amyloid precursor protein, APP) plays a central role in the pathophysiological processes in AD, which is characterized by progrediating neuronal degeneration with amyloid deposits [32]. By enzymatic processing of APP, the peptide amyloid beta (Aβ) 1–42 is generated which is highly prone to aggregation and is the major constituent of the amyloid plaques that form in the brain. Aβ1–42 is also used as a CSF biomarker for AD [33]. In this study, we detected Aβ1–14, 1–15, 1–16, 1–17, 1–19, and 5–15 (Figure 5 a). The existence of several of these fragments have been recently reported in CSF in a study using immunoprecipitation in combination with mass spectrometry [34]. The C-termini of these fragments span the α-secretase cleavage site and may thus be markers of non amyloidogenic APP processing that may be protective from AD [35]. The identification of Aβ5–15 is the first report of this truncated form in CSF. The identification of Aβ peptides starting at position 5 is especially interesting since such peptides may represent the activity of an APP processing pathway that is up-regulated after inhibition of the major Aβ producing enzyme BACE1 [36], [37] and CSF Aβ5-X peptides may be useful as pharmacodynamic markers in trials of BACE1-inhibitors [38].

Bottom Line: Analysis of the extracts by offline LC-MALDI MS resulted in the detection of 3,000-4,000 peptide-like features.Out of these, 730 peptides were identified by MS/MS.The identified peptides were found to originate from 104 proteins, of which several have been reported to be involved in different disorders of the central nervous system.

View Article: PubMed Central - PubMed

Affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.

ABSTRACT
We report on the analysis of endogenous peptides in cerebrospinal fluid (CSF) by mass spectrometry. A method was developed for preparation of peptide extracts from CSF. Analysis of the extracts by offline LC-MALDI MS resulted in the detection of 3,000-4,000 peptide-like features. Out of these, 730 peptides were identified by MS/MS. The majority of these peptides have not been previously reported in CSF. The identified peptides were found to originate from 104 proteins, of which several have been reported to be involved in different disorders of the central nervous system. These results support the notion that CSF peptidomics may be viable complement to proteomics in the search of biomarkers of CNS disorders.

Show MeSH
Related in: MedlinePlus