Abstract
Thermal stabilization of the complex between polycytidylic acid [poly(C)] and the modified schizophyllan (SPG) whose hydrophilic side-chain glucose groups are selectively removed utilizing mild Smith-degradation has been investigated. With the decrease in the side-chain glucose groups of schizophyllan, the complex with poly(C) can be considerably stabilized compared with unmodified SPG; for example, the Tm value after the removal of the side-chain glucose groups from 33.3 (unmodified) to 1.0 is enhanced by 14°C. In addition, the thermal stabilization effect is even operative under the physiological conditions ([NaCl] = 0.15 mol dm-3). This effect is exerted owing to the construction of the hydrophobic atmosphere around the complex. Although schizophyllan lost the side-chain glucose groups, it still kept the protection effect of the bound poly(C) chain against RNaseA-mediated hydrolysis as observed for unmodified schizophyllan. The assessment of the cytotoxicity for A375:human malignant melanoma, and HL60:human promyelocytic leukemia revealed that the modified schizophyllan scarcely increases the cytotoxicity. These results indicate that the present modification for schizophyllan is of great significance in a viewpoint to develop the practical gene carriers operative even under the physiological conditions.
Original language | English |
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Pages (from-to) | 403-411 |
Number of pages | 9 |
Journal | Biopolymers |
Volume | 75 |
Issue number | 5 |
DOIs | |
Publication status | Published - Dec 5 2004 |
All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Biomaterials
- Organic Chemistry