Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two forms of abnormal fibrillary protein deposition are considered: amyloidosis and fibrillary (immunotactoid) glomerulonephritis. Amyloid is characterised by an antiparallel, beta-pleated configuration which imparts to it a unique apple-green birefringence after Congo red staining. Inspite of its fairly constant physical properties, the chemical composition of amyloid fibrils is amazingly diverse, encomposing AA protein, light chain fragments, transthyretin, procalcitonin, islet amyloid polypeptide, atrial natriuretic peptides, beta-amyloid protein, beta-2-microglobulin, cystatin C, gelsolin, apolipoprotein A1, lyzozyme and their mutant variants. Amyloid P component and heparan sulphate proteoglycan are ubiquitous non-fibrillary amyloid components which have significant roles in the amyloidogenetic process, as do also precursor fibril proteins. Different amyloid fibril proteins relate to different amyloidosis syndromes and different histological patterns, and provide the basis for new diagnostic approaches to this disorder. Glomerular deposits in fibrillary glomerulonephritis (FGN), although often mistaken for amyloid, differ from it in its negative Congophilia, wider fibril width and highly organised, microtubular-tactoidal appearance ultrastructurally. FGN is essentially a primary glomerulopathy resulting in progressive renal failure. Despite certain differences, intriguing similarities between both entities of fibrillary deposition pose a challenge to researchers as to the mechanisms of abnormal protein crystallization and fibril formation in tissues.
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PMID:Fibrillary deposits: amyloids and tactoids. 890 98

Optimal application of biological mass spectrometry (MS) in combination with two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) of human cerebrospinal fluid (CSF) can lead to the identification of new potential biological markers of neurological disorders. To this end, we analyzed a number of 2-D PAGE protein spots in a human CSF pool using spot co-localization, N-terminal sequencing, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and nanoliquid chromatography-electrospray ionization-time of flight-mass spectrometry (nanoLC-ESI-TOF-MS) with tandem MS switching. Our constructed CSF master contained 469 spots after image analysis and processing of 2-D gels. Upon visual inspection of our CSF master with the CSF pattern available on the ExPASy server, it was possible to locate and annotate 15 proteins. N-terminal sequence analysis and MALDI-MS peptide mass fingerprint analysis of both silver- and Coomassie Brilliant Blue (CBB) G-250-stained protein spots after in situ trypsin digest not only confirmed nine of the visually annotated spots but additionally resolved the identity of another 13 spots. Six of these proteins were not annotated on the 2-D ExPASy map: complement C3 alpha-chain (1321-1663), complement factor B, cystatin C, calgranulin A, hemoglobin beta-chain, and beta-2-microglobulin. It was clear that MALDI-MS identification from CBB G-250-stained, rather than from silver-stained, spots was more successful. In cases where no N-terminal sequence and/or no clear MALDI-MS result was available, nanoLC-ESI-TOF-MS and tandem MS automated switching was used to clarify and/or identify these protein spots by generating amino acid sequence tags. In addition, enrichment of the concentration of low-abundant proteins on 2-D PAGE was obtained by removal of albumin and immunoglobulins from the CSF pool using affinity chromatography. Subsequent analysis by 2-D PAGE of the fractionated CSF pool showed various new silver-stainable protein spots, of which four were identified by nanoLC-ESI-TOF-MS and tandem MS switching. No significant homology was found in either protein or DNA databases, indicating than these spots were unknown proteins.
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PMID:Identification of two-dimensionally separated human cerebrospinal fluid proteins by N-terminal sequencing, matrix-assisted laser desorption/ionization--mass spectrometry, nanoliquid chromatography-electrospray ionization-time of flight-mass spectrometry, and tandem mass spectrometry. 1089 37

Biomolecular interaction analysis mass spectrometry (BIA/MS) is a two-dimensional analytical technique that quantitatively and qualitatively detects analytes of interests. In the first dimension, surface plasmon resonance (SPR) is utilized for detection of biomolecules in their native environment. Because SPR detection is non-destructive, analyte(s) retained on the SPR-active sensor surface can be analyzed in a second dimension using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The qualitative nature of the MALDI-TOF MS analysis complements the quantitative character of SPR sensing and overcomes the shortcomings of the SPR detection stemming from the inability to differentiate and characterize multi-protein complexes and non-specific binding. In this work, the benefit of performing MS analysis following SPR sensing is established. Retrieval and detection of four markers present in biological fluids (cystatin C, beta-2-microglobulin, urinary protein 1 and retinol binding protein) was explored to demonstrate the effectiveness of BIA/MS in simultaneous detection of clinically related biomarkers and delineation of non-specific binding. Furthermore, the BIA/MS limit of detection at very low SPR responses was investigated. Finally, detection of in-vivo assembled protein complexes was achieved for the first time using BIA/MS.
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PMID:Analysis of native proteins from biological fluids by biomolecular interaction analysis mass spectrometry (BIA/MS): exploring the limit of detection, identification of non-specific binding and detection of multi-protein complexes. 1167 91

The feasibility of multi-affinity ligand surfaces in biomolecular interaction analysis-mass spectrometry (BIA/MS) was explored in this work. Multi-protein affinity surfaces were constructed by utilizing antibodies to beta-2-microglobulin, cystatin C, retinol binding protein, transthyretin, serum amyloid P and C-reactive protein. In the initial experiments, all six antibodies were immobilized on a single site (flow cell) on the sensor chip surface, followed by verification of the surface activity via separate injections of purified proteins. After an injection of diluted human plasma aliquot over the antibodies-derivatized surfaces, and subsequent MALDI-TOF MS analysis, signals representing five out of the six targeted proteins were observed in the mass spectra. Further, to avoid the complexity of the spectra, the six proteins were divided into two groups (according to their molecular weight) and immobilized on two separate surfaces on a single sensor chip, followed by an injection of human plasma aliquot. The resulting mass spectra showed signals from all proteins. Also, the convolution resulting from the multiply charged ion species was eliminated. The ability to create such multi-affinity surfaces indicates that smaller-size ligand areas/spots can be employed in the BIA/MS protein interaction screening experiments, and opens up the possibilities for construction of novel multi-arrayed SPR-MS platforms and methods for high-throughput parallel protein interaction investigations.
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PMID:Design and use of multi-affinity surfaces in biomolecular interaction analysis-mass spectrometry (BIA/MS): a step toward the design of SPR/MS arrays. 1255 34

The utility of biomolecular interaction analysis-mass spectrometry (BIA/MS) in screening for protein-protein interactions was explored in this work. Experiments were performed in which proteins served as ligands for screening of possible interactions with other proteins from human plasma and urine. The proteins utilized were beta-2-microglobulin, cystatin C (cysC), retinol binding protein (RBP), transthyretin (TTR), alpha-1-microglobulin, C-reactive protein, transferrin and papain. The immobilization of functionally active proteins was confirmed via interactions with antibodies to the corresponding proteins. Various dilutions of human urine and plasma were injected over the protein-derivatized surfaces. It was observed that the urine injections generally yielded smaller SPR responses than those observed after the plasma injections. The BIA/MS experiments did not reveal novel protein-protein interactions, although several established interactions (such as those between RBP and TTR, and cysC and papain) were validated. Few protein ligand deficiencies (such as truncations) leading to false negative and false positive BIA/MS results were also discovered.
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PMID:Delineating protein-protein interactions via biomolecular interaction analysis-mass spectrometry. 1255 33

Reported here, human urine samples were analyzed for beta-2-microglobulin (beta2m), transthyretin (TTR), cystatin C, urine protein 1 (UP1), retinol binding protein (RBP), albumin, transferrin, and human neutrophil defensin peptides (HNP) using mass spectrometric immunoassay (MSIA). MSIA is a unique analytical technique, which allows for the generation of distinct protein profiles of specific target proteins from each subject, which may be subsequently used in comparative protein expression profiling between all subjects. Comparative profiling allows for the rapid identification of variations within individual protein expression profiles. Although the majority of analyses performed in this study revealed homology between study participants, roughly one-quarter showed variation in the protein profiles. Some of these observed variants included a point mutation in TTR, absence of wild-type RBP, monomeric forms UP1, a novel beta2m glycated end product and altered HNP ratios. MSIA has been previously used in the analysis of blood proteins, but this study shows how MSIA easily transitions to the analysis, of urine samples. This study displays how qualitative urine protein differentiation is readily achievable with MSIA and is useful in identifying proteomic differences between subjects that might be otherwise overlooked with other analytical techniques due to complexity of the resulting data or insufficient sensitivity.
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PMID:Comparative urine protein phenotyping using mass spectrometric immunoassay. 1271 33

The diagnosis of Alzheimer's disease (AD), the most common form of dementia in the general population, usually relies upon the presence of typical clinical features and structural changes on brain magnetic resonance imaging. Over the last decade, a number of biological abnormalities have been reported in the cerebrospinal fluid (CSF) of AD patients, in particular altered levels of the tau protein and the 1-42 fragment of the amyloid precursor protein. These, however, have not yet proved sensitive and specific enough to be included in the diagnostic criteria for AD, leaving plenty of room for the search of novel biomarkers. The present study describes the analysis of CSF polypeptides by a protein-chip array technology called surface enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS). Using this approach, we detected statistically significant quantitative differences (p < 0.05) regarding four overexpressed and one underexpressed polypeptides in the CSF of AD patients as compared to healthy controls. Four of them were further purified by strong anionic exchange chromatography (SAX) and identified by MS analysis as cystatin C, two beta-2-microglobulin isoforms, an unknown 7.7 kDa polypeptide, and a 4.8 kDa VGF polypeptide. The combination of the five polypeptides for the diagnosis of AD allowed to classified six AD patients out of the nine included in this study and all the ten controls, which means in this small cohort that the specificity and sensitivity are 100% and 66%, respectively. This study, based on the protein-chip array technology, demonstrates the presence in the CSF of novel potential biomarkers for AD, which may be used for the diagnosis and perhaps the assessment of the severity and progression of the disease.
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PMID:A panel of cerebrospinal fluid potential biomarkers for the diagnosis of Alzheimer's disease. 1292 74

The p21Waf1/Cip1/Sdi1 cyclin-dependent kinase inhibitor is a key regulator of cell cycle progression and has also been observed to influence the expression of genes associated with several age-related disorders. Previous work has shown that expression of p21 in tumour cells mediates an antiapoptotic and mitogenic paracrine effect, which is in contrast to the arrested state of p21-expressing cells. Here, we have employed SELDI-MS technology to characterise, at a proteomic level, factors released from HT-1080 human fibrosarcoma cells displaying inducible p21 expression. Conditioned media from induced and noninduced cells were profiled on a range of diverse ProteinChip arrays and subjected to SELDI-MS analysis. Evaluation of proteins binding onto IMAC, Q10 or CM10 surfaces led to the discovery of a number of putative p21-regulated factors. We further validated three p21-regulated proteins observed at 10.2, 11.7 and 13.4 kDa. Using Q Ceramic HyperD fractionation columns, we were able to selectively enrich for each of these three proteins. Subsequent SDS-PAGE and MS analysis of tryptic digests identified the 13.4 kDa protein as cystatin C and the 10.2 kDa protein as pro-platelet basic protein (PPBP). Judging by the apparent MW and the pI of the 11.7 kDa protein, we reasoned that it may be beta-2-microglobulin, which was confirmed by subsequent identification. Increased levels of cystatin C and beta-2-microglobulin in conditioned media from p21-expressing cells was confirmed by antibody capture experiments using anticystatin C and anti-beta-2-microglobulin antibodies on preactivated PS-20 arrays. Western blot analysis demonstrated increased expression of intracellular and extracellular cystatin C and beta-2-microglobulin in p21-expressing cells, compared to noninduced controls. Increased levels of PPBP were validated in cell lysates from p21-expressing cells. The three secreted factors that we have identified in this study, have all been shown previously to have growth modulating effects and, as such, may contribute to the observed mitogenic and anti-apoptotic paracrine activity of p21-expressing [corrected] cells.
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PMID:Proteomic analysis of factors released from p21-overexpressing tumour cells. 1673 31

Biosensors that utilize surface plasmon resonance (SPR) as a method of detection of protein interactions can be used for selective separation of proteins prior to MS analysis. The combination of SPR and MS results in a unique multiplexed detection technology capable of both quantitative and qualitative protein analysis. To further the development of a high-throughput SPR-MS approach, the possibility of arraying binding ligands on SPR chips for affinity capture of proteins and their MS analysis was explored. Antibodies to beta-2-microglobulin, cystatin C, transferrin, and insulin-like growth factors I and II were arrayed on a large number of SPR chips. Human plasma samples were injected over the antibody array chips in an SPR Biosensor, after which on-chip MS analysis was performed to detect the bound proteins. Signals from the targeted proteins were observed for each antibody-derivatized chip, indicating successful antibody immobilization and protein capture. The SPR-MS arrays are robust, highly reproducible, and are capable of high-throughput analysis.
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PMID:Surface plasmon resonance-enabled mass spectrometry arrays. 1691 66

Proteomic analysis enables us to identify dementia-related protein profiles of both genetic and environmental origins. In this review, current proteomics technologies are described including many examples of clinical proteomics studies. Many of these studies present only results of the discovery phase. Progression to the validation phase was achieved by developing more advanced proteomics technologies such as fluorescence two-dimensional differential gel electrophoresis or isobaric tagging for relative and absolute protein quantification. These technologies will lead to the design of several new Alzheimer's disease-related protein panels for the analysis of CSF. On these new panels, established markers such as tau and Abeta42 will be used in combination with novel markers, for example beta-2-microglobulin, brain-derived neurotrophic factor 1 and fragments of cystatin C. However, there are still limitations to using proteomic assays. The preparation of homogeneous sample material is difficult due the complexity of brain tissue. Laser capture microdissection and recently developed more sensitive proteomics methods, for example fluorescence saturation labelling, will overcome these limitations. Combining proteomics with approaches at the level of the genome and transcriptome followed by interpretation by systems biology will soon shed further light on dementia-related pathogenesis.
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PMID:The role of proteomics in dementia and Alzheimer's disease. 1925 91


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