The wheat germ agglutinin-fractionated proteome of subjects with Alzheimer's disease and mild cognitive impairment hippocampus and inferior parietal lobule: Implications for disease pathogenesis and progression.

Lectin affinity chromatography is a powerful separation technique that fractionates proteins by selectively binding to specific carbohydrate moieties characteristic of protein glycosylation type. Wheat germ agglutinin (WGA) selectively binds terminal N-acetylglucosamine (O-GlcNAc) and sialic acid moieties characteristic of O-linked glycosylation. The current study utilizes WGA affinity chromatography to fractionate proteins from hippocampus and inferior parietal lobule (IPL) from subjects with Alzheimer's disease (AD) and arguably its earliest form, mild cognitive impairment (MCI).

In vivo oxidative stress in brain of Alzheimer disease transgenic mice: Requirement for methionine 35 in amyloid beta-peptide of APP.

Numerous studies have demonstrated oxidative damage in the central nervous system in subjects with Alzheimer disease and in animal models of this dementing disorder. In this study, we show that transgenic mice modeling Alzheimer disease-PDAPP mice with Swedish and Indiana mutations in the human amyloid precursor protein (APP)-develop oxidative damage in brain, including elevated levels of protein oxidation (indexed by protein carbonyls and 3-nitrotyrosine) and lipid peroxidation (indexed by protein-bound 4-hydroxy-2-nonenal). This oxidative damage requires the presence of a single methionine residue at position 35 of the amyloid beta-peptide (Abeta), because all indices of oxidative damage in brain were completely prevented in genetically and age-matched PDAPP mice with an M631L mutation in APP.

Peptides and proteins in plasma and cerebrospinal fluid as biomarkers for the prediction, diagnosis, and monitoring of therapeutic efficacy of Alzheimer's disease.

Alzheimer's disease (AD) affects millions of persons worldwide. Earlier detection and/or diagnosis of AD would permit earlier intervention, which conceivably could delay progression of this dementing disorder. In order to accomplish this goal, reliable and specific biomarkers are needed.

Proteomics in animal models of Alzheimer's and Parkinson's diseases.

The risk of developing neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD) increases with age. AD and PD are the two most common neurodegenerative diseases that currently affect millions of persons within the United States population. While many clues about the mechanisms of these disorders have been uncovered, to date, the molecular mechanisms associated with the cause of these diseases are not completely understood.

Development of a high-throughput IMS-IMS-MS approach for analyzing mixtures of biomolecules.

A high-throughput approach for biomolecule analysis is demonstrated for a mixture of peptides from tryptic digest of four proteins as well as a tryptic digests of human plasma. In this method a chip based electrospray autosampler coupled to a hybrid ion mobility (IMS) mass spectrometer (MS) is utilized to achieve rapid sample analysis. This high-throughput measurement is realized by exploiting the direct infusion capability of the chip based electrospray with its rapid sample manipulating capability as well as a high sensitive IMS-MS with a recently developed IMS-IMS separation technique that can be multiplexed to provide greater throughput.

Quantitative proteomics of a presymptomatic A53T alpha-synuclein Drosophila model of Parkinson disease.

A global isotopic labeling strategy combined with multidimensional liquid chromatographies and tandem mass spectrometry was used for quantitative proteome analysis of a presymptomatic A53T alpha-synuclein Drosophila model of Parkinson disease (PD). Multiple internal standard proteins at different concentration ratios were spiked into samples from PD-like and control animals to assess quantification accuracy. Two biological replicates isotopically labeled in forward and reverse directions were analyzed.

Examining the proteome of Drosophila across organism lifespan.

A survey of the proteome of Drosophila melanogaster at nine time points across the adult lifespan based on several mass-spectrometry-based techniques is presented. In total, there is evidence for 5902 unique peptides corresponding to 1699 different proteins. Of hundreds of relatively abundant components, many appear to be highly dynamic as the adult fly ages.

Lifetime proteomic profiling of an A30P alpha-synuclein Drosophila model of Parkinson's disease.

A survey of the proteome changes in an A30P alpha-synuclein Drosophila model of Parkinson's disease (PD) in comparison to age-matched controls is presented for seven different ages across the adult lifespan. The data were acquired by a shotgun proteomic approach that involves multidimensional liquid chromatographies coupled to mass spectrometry and database searching techniques. Semiquantitative analysis to assess relative changes in protein expression between the Drosophila PD model and age-matched controls provides evidence that 28, 19, 12, 5, 7, 23, and 17 proteins are significantly differentially expressed at days 1, 10, 20, 30, 40, 50, and 60, respectively.

Protein expression in a Drosophila model of Parkinson's disease.

Liquid chromatographies coupled to mass spectrometry and database analysis techniques are used to carry out a large-scale proteome characterization for a Drosophila model of Parkinson's disease. Semiquantitative analysis is performed on A30P alpha-synuclein expressing transgenic Drosophila and a control lacking the gene at presymptomatic, early, and advanced disease stages. Changes in gene expression at the level of the proteome are compared with changes reported from published transcriptome measurements.

Proteome profiling for assessing diversity: analysis of individual heads of Drosophila melanogaster using LC-ion mobility-MS.

The proteomes of three heads of individual Drosophila melanogaster organisms have been analyzed and compared by a combination of liquid chromatography, ion mobility spectrometry, and mass spectrometry approaches. In total, 197 proteins are identified among all three individuals (an average of 120 +/- 20 proteins per individual), of which at least 101 proteins are present in all three individuals. Within all three datasets, more than 25 000 molecular ions (an average of 9000 +/- 2000 per individual) corresponding to protonated precursor ions of individual peptides have been observed.

Mapping the proteome of Drosophila melanogaster: analysis of embryos and adult heads by LC-IMS-MS methods.

Multidimensional separations combined with mass spectrometry are used to study the proteins that are present in two states of Drosophila melanogaster: the whole embryo and the adult head. The approach includes the incorporation of a gas-phase separation dimension in which ions are dispersed according to differences in their mobilities and is described as a means of providing a detailed analytical map of the proteins that are present. Overall, we find evidence for 1133 unique proteins.

Nanoflow LC/IMS-MS and LC/IMS-CID/MS of protein mixtures.

A simple ion trap/ion mobility/time-of-flight (TOF) mass spectrometer has been coupled with nanoflow liquid chromatography to examine the feasibility of analyzing mixtures of intact proteins. In this approach proteins are separated using reversed-phase chromatography. As components elute from the column, they are electrosprayed into the gas phase and separated again in a drift tube prior to being dispersed and analyzed in a TOF mass spectrometer.