Characterization of a sialic-acid-rich mucus glycoprotein secreted by a premalignant human colorectal adenoma cell line
✍ Scribed by Anthony P. Corfield; John R. Clamp; Angela D. Casey; Christos Paraskeva
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- French
- Weight
- 832 KB
- Volume
- 46
- Category
- Article
- ISSN
- 0020-7136
No coin nor oath required. For personal study only.
✦ Synopsis
The human colonic cell line PC/AA, derived from an adenoma, retains in vitro colonic cell differentiation, notably the production of mucus glycoproteins. The PC/AA adenoma cells produce an extracellular gel layer in culture. The PC/AA gel could be isolated by extraction of the cell cultures with guanidine hydrochloride. The extracted material was purified by gel filtration and caesium chloride density-gradient centrifugation and showed properties typical of mucus glycoproteins, namely, a carbohydrate content above 60% of dry weight rich in N-acetylgalactosamine and sialic acid and low in mannose; an amino acid composition with high serine threonine and proline content; a molecular weight above 1,000 kDa on Sepharose CL 48 chromatography and on SDS-polyacrylamide gel electrophoresis under reducing conditions (>ZOO kDa); a buoyant density of approximately I .48 g/ml and the release of oligosaccharides by the alkaline pelimination reaction. Comparison of the gel mucus glycoprotein purified from premalignant PC/AA cells with normal human colon much showed that it has a higher sialic acid content. This suggests that higher sialic acid levels may precede the development of malignancy.
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