Examination of corneal proteoglycans and glycosaminoglycans by rotary shadowing and electron microscopy
| Autor: | John E. Scott, Christine Cummings, John D. Gregory, Helmut W. Stuhlsatz, Helmut Greiling, Shridhar P. Damle |
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| Rok vydání: | 1990 |
| Předmět: |
Keratan sulfate
Alginates Molecular Conformation Dermatan Sulfate Methylcellulose Biochemistry Dermatan sulfate law.invention Glycosaminoglycan Cornea chemistry.chemical_compound Structural Biology law Hyaluronic acid Keratin medicine Animals Humans Hyaluronic Acid Molecular Biology chemistry.chemical_classification Heparin Chondroitin Sulfates General Medicine Molecular biology Microscopy Electron medicine.anatomical_structure chemistry Keratan Sulfate Methyl cellulose Cattle Proteoglycans Heparitin Sulfate Rabbits Electron microscope |
| Zdroj: | International journal of biological macromolecules. 12(3) |
| ISSN: | 0141-8130 |
| Popis: | Proteoglycans (PGs) from cornea and their relevant glycosaminoglycan (GAG) chains, dermatan sulphate (DS) and keratin sulphate (KS), were examined by electron microscopy following rotary shadowing, and compared with hyaluronan (HA), chondroitin sulphate (CS), alginate, heparin, heparan sulphate (HS) and methyl cellulose. Corneal DS PG had the tadpole shape previously seen in scleral DS FG, and the images from corneal KS PG could be interpreted similarly, although the GAG (KS) chains were very much fainter than those of DS PG GAG. Isolated GAG (KS, DS, CS, HA, etc.) examined in the same way showed images that decreased very significantly in clarity and contrast, in the sequence HA greater than DS greater than CS greater than KS. The presence of secondary and tertiary structures in the GAGs may be at least partly responsible for these variations. HA appeared to be double stranded, and DS frequently self-aggregated, KS and HS showed tendencies to coil into globular shapes. It is concluded that it is unsafe to assume the absence of GAGs, based on these techniques, and quantitative measurements of length may be subject to error. The results on corneal DS PG confirm and extend the hypothesis that PGs specifically associated with collagen fibrils are tadpole shaped. |
| Databáze: | OpenAIRE |
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