Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many tumour-specific antigens in gastrointestinal cancers have carbohydrate immuno-determinants. These epitopes can be identified by lectins and monoclonal antibodies. By using fluorescein-isothiocyanate (FITC)-conjugated peanut agglutinin (PNA) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) we have investigated glycoproteins carrying altered carbohydrate epitopes in normal and carcinomatous human colorectal mucosa. In normal mucosa PNA stained goblet cell glycoconjugates in the supranuclear (Golgi) distribution. After neuraminidase pretreatment PNA stained actual mucin goblet itself at all levels of the crypts. Colorectal carcinomas displayed a strong and direct binding of PNA to apical cell membranes of carcinomatous cells and intraluminal secretions. Analysis of the glycoproteins by SDS-PAGE and PNA-labelling revealed four carcinoma-associated glycoproteins (26kD, 32kD, 35kD and 50kD). In addition, four glycoproteins (29kD, 30kD, 33kD and 36kD) common to normal and carcinomatous colorectal mucosa could be identified. All of these glycoproteins differed in their molecular weight from those in red cell controls which bind PNA only after desialylation. The study shows that the expression of PNA-binding sites in colorectal carcinomas signifies a cancer-associated carbohydrate alteration. Four carcinoma-associated glycoprotein antigens could be detected by this lectin. The antigens we have identified might be useful in the isolation and purification of more selective reagents for the serologic detection of colorectal cancer.
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PMID:Identification of glycoproteins expressing tumour-associated PNA-binding sites in colorectal carcinomas by SDS-GEL electrophoresis and PNA-labelling. 243 45

Class II antigens from the Xenopus laevis MHC (f haplotype) were identified by using a rabbit antihuman class II beta-chain serum (anti-p29boost). This xenoantiserum inhibits bidirectional Xenopus MLR (but not PHA-stimulation), recognizes the same molecules as certain MHC-linked Xenopus alloantisera, and immunoprecipitates class II molecules from Xenopus cells consistent with the tissue distribution of mammalian class II molecules. The Xenopus class II molecules are composed of two different chains, both of which are 30 to 35kD transmembrane glycoproteins. The alpha-chains have some N-terminal sequence homology with mammalian class II alpha-chains (both I-E/DR and I-A/DC); the beta-chains are directly recognized by anti-p29boost and have a markedly increased SDS gel mobility under nonreducing conditions. During biosynthesis, they are noncovalently associated with a number of other chains, including ones at 25kD, 33kD, and 40 to 45kD. The alpha-chains bear three N-linked glycans (two Endo H insensitive in mature material) and the beta-chains bear two (one Endo H insensitive). Unlike most mammalian class II molecules, the deglycosylated beta-chains are significantly larger and more acidic than the alpha-chains.
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PMID:Xenopus MHC class II molecules. I. Identification and structural characterization. 315 30

Two highly metastatic human tumor cell lines, SLU-M1 SLU-M2, were established by in vivo selection in Balb/c-nu/nu mice of SLU-1 xenotransplants derived from an adenocarcinoma of the sigmoid colon. Metastatic spread was screened by transplantation of tissues from various organs of s.c.-tumor-bearing nu/nu mice. A monoclonal antibody, mab ME6H2, prepared against a membrane fraction of HT29 cells, also derived from an adenocarcinoma of the colon, showed high 125I-mab ME6H2 binding only to HT29 and SLU-1 cells, whereas hardly any binding was recorded for SLU-M1 and SLU-M2 cells. All cells of the HT29 and SLU-1 populations exhibited a positive immunofluoresence (IF) but only 1-5% of the SLU-M2 and 10-15% of the SLU-M1 subpopulation. A number of other tumor cell lines did not express the ME6H2 target antigen except for line MCF7, derived from an adenocarcinoma of the breast, which showed an IF positive reaction of 100% of the cells but only 25% of mab binding compared to HT29 and SLU-1 cells. The data indicate that expression of the ME6H2 target antigen is adenocarcinoma-specific and lack of expression is a marker for the metastatic potential of these cells. Mab ME6H2 was rapidly internalized upon binding to viable HT29 cells, resulting in an enhancement of cell growth in vitro and tumor growth in vivo. The mab ME6H2-defined target antigen was isolated from cell lysates by antibody affinity chromatography and was identified as a double band in SDS-PAGE with 31kD and 33kD molecular mass usually present in equal amounts.
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PMID:Lack of expression of a 31/33kD surface protein on human colon carcinoma cells is a marker for metastasizing potential. 787 5

Epithelial-mesenchymal interactions are crucial for various epithelial tissue organizations and epimorphin is one of the important signaling molecules from the mesenchyme. The sequence analysis of a human homologue revealed that both of primary and predicted secondary structures of epimorphin are highly conserved among species and this molecule has some isoforms including a putative soluble type. I found that human epimorphins also have a large discrepancy in molecular masses as the case of mouse (around 33kD are predicted by the sequences whereas two protein bands of 60-70kD and 150kD are detected in the cells), and it can be explained, at least in part, by the SDS-resistant complexes formed in the microsomal membranes.
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PMID:Molecular cloning of human epimorphin: identification of isoforms and their unique properties. 846 9