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Rigdova K.,University of Swansea | Wang Y.,University of Swansea | Ward M.,Proteome science Plc | Griffiths W.J.,University of Swansea
Biochemical and Biophysical Research Communications

Here we report a new method for oxosteroid identification utilizing "tandem mass tag hydrazine" (TMTH) carbonyl-reactive derivatisation reagent. TMTH is a reagent with a chargeable tertiary amino group attached through a linker to a carbonyl-reactive hydrazine group. Thirty oxosteroids were analysed after derivatisation with TMTH by electrospray ionization mass spectrometry (ESI-MS) and were found to give high ion-currents compared to underivatised molecules. ESI-tandem mass spectrometry (MS/MS) analysis of the derivatives yielded characteristic fragmentation patterns with specific mass reporter ions derived from the TMT group. A shotgun ESI-MS method incorporating TMTH derivatisation was applied to a urine sample. © 2014 The Authors. Published by Elsevier Inc. Source

Velayudhan L.,Kings College London | Velayudhan L.,University of Leicester | Killick R.,Kings College London | Hye A.,Kings College London | And 9 more authors.
Journal of Alzheimer's Disease

Diagnosis of the progressive neurodegenerative disorder Alzheimer's disease (AD) can only definitively be made postmortem. The most promising AD biomarkers identified to date are found in cerebrospinal fluid (CSF). Among these, one of the most interesting candidates is transthyretin (TTR), the carrier of thyroxine and retinol, which also binds with amyloid-β (Aβ), and it has been suggested that it protects against Aβ deposition. A biomarker detectable in plasma would have great diagnostic value and could be of use for determining disease progression and the monitoring of therapeutic efficacy due to its greater accessibility over CSF-based markers. We aimed to validate TTR as a prognostic marker in AD and to determine its relation with cognitive measures. We examined the plasma protein levels of TTR in 90 people with late-onset AD and 50 age-matched non-demented controls (NDC) by immunoblotting and found lower plasma TTR levels in AD compared to NDC (p = 0.004). We then quantified plasma TTR by enzyme-linked immunosorbent assays in a larger independent cohort (n = 270) including subjects with mild to severe AD. Plasma TTR levels were significantly lower in AD cases with rapid cognitive decline and with severe cognitive impairment. Regression analyses showed plasma TTR levels also predicted cognitive decline over the ensuing 6 months. These data indicate that plasma TTR is a strong candidate AD biomarker that should be included in the development of blood based biomarker panels for disease diagnosis and also suggests that plasma TTR is a marker of disease severity and progression. © 2012 - IOS Press and the authors. All rights reserved. Source

Thambisetty M.,U.S. National Institute on Aging | Simmons A.,Kings College London | Hye A.,Kings College London | Campbell J.,Proteome science Plc | And 13 more authors.

Peripheral biomarkers of Alzheimer's disease (AD) reflecting early neuropathological change are critical to the development of treatments for this condition. The most widely used indicator of AD pathology in life at present is neuroimaging evidence of brain atrophy. We therefore performed a proteomic analysis of plasma to derive biomarkers associated with brain atrophy in AD. Using gel based proteomics we previously identified seven plasma proteins that were significantly associated with hippocampal volume in a combined cohort of subjects with AD (N = 27) and MCI (N = 17). In the current report, we validated this finding in a large independent cohort of AD (N = 79), MCI (N = 88) and control (N = 95) subjects using alternative complementary methods-quantitative immunoassays for protein concentrations and estimation of pathology by whole brain volume. We confirmed that plasma concentrations of five proteins, together with age and sex, explained more than 35% of variance in whole brain volume in AD patients. These proteins are complement components C3 and C3a, complement factor-I, γ-fibrinogen and alpha-1-microglobulin. Our findings suggest that these plasma proteins are strong predictors of in vivo AD pathology. Moreover, these proteins are involved in complement activation and coagulation, providing further evidence for an intrinsic role of these pathways in AD pathogenesis. Source

King's College London and PROTEOME science PLC | Date: 2012-11-21

The present invention provides materials and methods relating to screening for compounds useful in the treatment of Alzheimers disease and related conditions. In particular, screening methods using tyrosine kinases are provided, as are methods relating to the role of tyrosine kinases as therapeutic targets.

Proteome science PLC and King's College London | Date: 2014-07-24

Methods of screening for candidate compounds capable of inhibiting activity of fyn in phosphorylating tau protein at Y394 or binding to fyn to inhibit interaction with tau protein at Y394, including determining whether, and optionally the extent, the candidate compounds have these capabilities under conditions where fyn has these capabilities in the absence of the candidate compound. Methods of screening for substances capable of promoting dephosphorylation of tau protein by a phosphatase at a site of tau protein including contacting a candidate substance, the tau protein and a phosphatase capable of dephosphorylating the tau protein under conditions where the phosphatase is capable of dephosphorylating the site in absence of the candidate substance, where the kinase is fyn; determining whether, and optionally the extent, the candidate substance promotes dephosphorylation of the tau protein at the site; and selecting the candidate substance which promotes dephosphorylation of the tau protein the sites.

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